fm radio handbook in <pdf>

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IzmUv B‚n\ Hcp Sn.hn. B‚ n\sb°pdn®v ]dbptºmƒ \ΩpsS a\ nseØp∂Xv bmKn B‚n\bpsS Nn{XamWv. ssUt]mfw dn^vfIvSdpw UbdIvtSgvkpsa√map≈ bmKn B‚n\bn¬ \n∂pw hyXykvXamb Hcp B‚n\bmWv IzmUv B‚n\. bmKn B‚n\sb At]£n®v sNehv Ipdhpw IqSpX¬ ^ehp (better result) ap≈XmWnXv. IzmUv B≥cn\m \n¿ΩmWw hnhcn°p∂Xn\p ap≥]mbn bmKn B‚n\sb°pdn®v kw£n]vXambn hnhcn°mw.

bmKn B‚n\ P∏m≥Imc\mbncp∂ bmKn F∂ F©n\ob¿ cq]I¬∏\ sNbvX B‚n\bmWv bmKn B‚n\ Hcp dns^vfIvS¿ Hcp t^mƒUUv ssUt]mƒ, Ht∂m AXne[nItam UbdIvSdpIƒ F∂nh tN¿∂XmWv Hcp bmKn B‚ n\. ChbpsS Hmtcm∂ns‚bpw \ofhpw Ch XΩnep≈ AIehpw Hmtcm Sn.hn. kwt{]jW {^oIz≥kn°\pkcn®mWv Xocpam\n°s∏Sp∂Xv. AXmXp ÿesØ Sn.hn. kwt{]jW {]oIz≥kn°\pkcn®v bmKn B‚n\bmbncnI°pw B ÿesØ ISIfn¬ \n∂pw hmßphm≥ In´p∂Xv.

FM Radio Dxing Nandakumar Hobby home publications, Cochin - 22 Phone : 9349287808

dn^vsfIvS¿ (Reflector) bmKn B‚n\bpsS dn^vsfIvSdn\mbncn°pw G‰hpw \ofw IqSpX¬. CXv Aeqan\nbw IpgepIƒ sImt≠m sNºp IpgepIƒ sImt≠m \n¿Ωn°p∂p. Sn.hn. {]kcWnsb e£yam°n h®ncn°p∂ bmKn B‚n\bn¬ G‰hpw AIeØn¬ Ccn°p∂Xv dn^vsfIvSdmbncn°pw.

Price Rs: 100

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apJ-hpc inesbt∏mepw Aenbn°m≥ Ignhp≈ kwKoXsØ Cjv S an√mØXv inemlrZb≥am¿ am{Xambncn°pat√m ! tdUntbmbpsS Imew Ign™p F∂ [mcWbn¬ tdUntbm X´n≥]pdØv Dt]£n®hcpw, B{InISbn¬ hn‰hcpw Ct∏mƒ F^v.Fw. tdUntbm At\zjn®v XpSßnbncn°pIbmWv. kzImcy taJebn¬ ]pXnb ]pXnb F^v.Fw. tdUntbm tÃj\pIƒ tIcfØn¬ Bcw`n®v XpSßnbtXmsS hn‰gnbp∂ samss_¬ t^mWpIfn¬ 60 iXam\Ønepw F^v . Fw. tdUntbm D≈hbmsW∂v I®hS°m¿ km£ys∏SpØp∂p. F∂m¬ tIcfØns‚ `q{]IrXnbpsS {]tXyIXaqehpw, F^v.Fw. tdUntbm XcwKßfpsS t\¿tcJm k©mcKXn aqehpw, \ΩpsS \m´nse P\kmam\yØn\v Cu ]pXnb tdUntbm tÃj\pIfn¬ \n∂p≈ ]cn]mSnIƒ BkzZn°m\mImsX h∂ncn°pIbmWv. CXns\mcp ]cnlmcsa∂ \nebn¬ F^v.Fw. kwKoX t{]anIfpw, hnZqc F^v.Fw. tÃj\pIƒ {ihn°pI F∂Xv PohnXhrXw t]mep≈ tlm_nbmbn sIm≠p\S°p∂ \nch[n sSIv\ojy≥amcpsS klmbtØmsS Xømdm°nbncn°p∂ Cu ]pkvXIw, kwKoX t{]anIfmb F^v.Fw. t{imXm°ƒ°v XßepsS t^hdn‰v tÃj\pIƒ hy‡ambn e`n°m≥ Bhiyamb kmt¶XnI ⁄m\w e`yam°pw.

8

ASp-Ø-Xmbn Aep-an-\nbw Ipg¬ aS-°p-hm≥ XpSßmw. BZyw AS-bm-fs-- ∏-Sp-Øn-bXv (35 sk.ao.) aS°msX AXn\SpØ 70 sk.ao. ASbmfØn¬ BZyw aS°pI. XpS¿∂v ASpØ 70 sk.ao. ASbmfØnepw aS°pI. At∏mƒ CXv c≠p ImepIƒ°v \ofw IqSnb (Nn{Xw 6) BIrXnbnembncn°pw. XpS¿∂v BZyw ASbmfs∏SpØnb (16.75) `mKØpw \memasØ ASbmfØn\pw (16.75) aS°pI. Ct∏mƒ B‚ n\ kaNXpcmIrXnbn¬ Bbncn°pw. HcphiØv \Sp`mKØmbn Ipgens‚ A{K߃ XΩn¬ t\cnb AIeØn¬ Ccn°p∂XpImWmw. CXp ]ckv]cw kv]¿in®n´ps≠lvIn¬ Aƒ∏w ]pdtIm´v hf®v AIØWw. Cu `mKamWv ^oUv t]mbn‚ v. ChnsS\n∂pw thWw ^oU¿ hb¿ AYhm tI_nƒ IWIvSv sNøm≥. Aeqan\nbw Ipg¬ hfbv°ptºmƒ A¬∏w {i≤n°Ww. tai∏pdtØm, HcpXSn°´bntem h®v AXns‚ AcnIn¬ ASbmfs∏SpØnb`mKw tN¿Øv h®v kmh[m\w hf®m¬ Aeqan\nbw Ipg¬ s]m´nt∏mImsX \∂mbn hfbpw. hf™ `mKw ]c∂ncn°psa∂p am{Xw. hfbv°phm≥ {]bmkamsW¶n¬ Ipgen\p≈n¬ aW¬ \nd®n´p hf®m¬ H´pw Xs∂ s]m´mXncn°pIbpw sNøpw. B‚ n\bpsS ^oUv t]mbn‚ n¬, ASpØncn°p∂ A{K߃ c≠pw Np‰nIbp]tbmKn®v ASnØp ]cØpI. Ch XΩn¬ t\cnb AIew (Hcp 3 mm) D≠mbncp∂m¬ aXn. ]cØnb `mKØv {Un¬ D]tbmKn®v sNdnb Zzmc߃ CSpI. Cu Zzmcßfn¬ ]n®f (Brass) \´pw t_mƒ´pap]tbmKn®v Hmtcm SmKpIƒ Dd∏n°Ww. (SmKv As√¶n¬ seKv sNºpsIm≠p≠m°nbn´p≈Xpw hen∏w IqSnb A{Kw \´pwt_mƒ´pw D]tbmKn®v Dd∏n°p∂Xn\pw hen∏w Ipd™

5

UbdIvSdpIƒ (Directors) Hcp bmKn B‚ n\bn¬ Ht∂m AXne[nItam UbdIvSdpIƒ D≠mImw. dn^vfIvSdnt\bpw ssUt]mfnt\bpw Imƒ \ofw Ipd™ UbdIvSdpIfpsS ÿm\w Ch c≠pw Ign™mWv . UbdIv S dpIfpw Aeqan\nbw As√¶n¬ sNºpIpgepIƒ sIm≠mWv \n¿Ωn°s∏Sp∂Xv. UbdIvSdpIfpsS FÆw IqSp∂Xn\\pkcn®v B‚n\m sKbn\pw IqSpsas∂mcp [mcWbp≠v. IqSpX¬ UbdIvSdpIfp≈ \ofw IqSnb B‚n\ Hcp A¥ mbn Nnesc¶nepw IcpXp∂p≠v.

t^mƒUvUv ssUt]mƒ (Folded Dipole) dn^vfIvSdn\pw UbdIvSdn\pw CS°p hcp∂ Fensa‚mWv t^mƒUUv ssUt]mƒ. CXpw Aeqan\nbw As√¶n¬ sNºp Ipg¬ sIm≠mWv \n¿Ωn®ncn°p∂Xv. t^mƒUUv ssUt]mfns\°pdn®v A¬∏w IqSn a\ nem°p∂Xv \∂mbncn°pw. lm^v thhv sUt]mfn (Half Wave Dipole) ¬ \n∂pamWv t^mƒUUv ssUt]mƒ D≠mbXv. kwt{]jWw sNøs∏Sp∂ CeIv t {Sm ams·‰nIv F\¿PnbpsS XcwKcq]w Nn{Xw 4˛¬ sImSpØncn°p∂p. Cu XcwKØns‚ F\¿Pn Fanj≥ XeØn\v ssd‰v BwKnfmbn ÿm]n®ncn°p∂ Hcp B‚n\bmWv CXv kzoIcn°phm≥ G‰hpw A\ptbmPyw. Cu XcwKØns‚ {IÃv As√¶n¬ {S^v (t]mkn‰ohv As√¶n¬ s\K‰ohv) `mKw kzoIcn°p∂Xn\mbn BsI thhv sewKv X v F∂ {Ko°v A£cw sIm≠v kqNn∏n°ptºmƒ B‚n\bpsS \ofw 1/2 s‚ ]IpXn \ofap≈ B‚n\ D]tbmKn®m¬ AXv \√ Hcp Syq¨Uv k¿Iyq´mbncn°pw. lm^v ssUt]mƒ B‚n\bn¬ AXns\ Xpey\ofap≈ c≠p IjWßfmbn apdn®v Hcp C≥kpte‰n¬, t\cnb

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AIeØn¬ (1/4 skao.) Øn¬ Dd∏n®ncn°p∂p. t\csØ kqNn∏n®ncn°p∂Xpt]mse Aeqan\nbw/sNºp IpgemWnXn\p ]tbmKn°p∂Xv.

ep-Iƒ 9mm (3/8”) hen-∏-ap-≈-h-bmWv D]-tbm-Kn-°p-∂-Xv. B‚nt\bpw XΩn¬ _‘n-∏n-°p-∂-Xn\v 1/2 ” ]nhnkn ss]∏p-I-fmWv D]-tbm-Kn-°p-∂X - v.

CØcsamcp lm^v thhv ssUt]mfns‚ sk≥{S¬ Cw]U≥kv GItZiw 72 Hmwkv Bbncn°pw. t{]mtbmKnIambn CXv 75 Hmwkv F∂v IcpXnt∏mcp∂p.

\n¿ΩmWw

c≠v lm^v thhv ssUt]mƒ B‚ n\Iƒ tN¿Øv \n¿Ωn°p∂XmWv t^mƒUUv ssUt]mƒ. t^mƒUUv ssUt]mfns‚ sk≥{S¬ Cw]U≥kv 288 Hmwkv AYhm {]mtbmKnIambn 300 Hmwkv Bbncn°pw.

sIm®n≥ F^v.Fw. {Sm≥kvan-‰-dn¬ \n∂p-ap≈ kn·-epIƒ kzoI-cn-°m-\p≈ Hcp IzmUv B‚n-\-sb-°p-dn®v BZy-ambn hnh-cn-°mw. BImihmWn 102.3 ¬ kwt{]-jWw sNøp∂ BImihmWn sIm®n, {^n©v Gcn-bm-bn¬ t]mepw, e`n-°phm≥ Cu B‚n-\bpw dn^vf-IvS-dp-w am{Xw aXn-bm-Ipw.

B‚n\ IzmUv B‚n\ bmKn B‚n-\b - psS {][m\ \yq\-Xb - mb Cw]-U≥kv ankv am®nwKv ]cn-l-cn-®p-sIm-≠p≈ Hcp B‚n-\-bmWv IzmUv B‚n\. F∂o ta≥a-Ifpw CXn-\p-≠v. B‚n-\bpw dn^vf-IvSp-am{Xw D]-tbm-Kn-®m¬ {^n©v Gcn-bm-bn¬ t]mepw \∂mbn FM kwt{]jWw kzoI-cn-°m≥ Ign-bp-∂p-≠.v IzmUv B‚n-\b - psS sk≥{S¬ Cw]-U≥kv 75 Bbn-cn-°pw. ]e ]T-\-ß-fn¬ \n∂pw a\- n-em°p-∂Xv IzmUv B‚n-\°v bmKn B‚n-\-sb-°mƒ 2dB sKbn≥ IqSp-X¬ Ds≠-∂m-Wv. bmKn B‚n-\-bpsS \n¿Ωm-W-Øn-se-∂-t]mse CXnepw Aep-an-\nbw As√-¶n¬ sNºv Ipgp-ep-I-fmWv D]-tbm-Kn-°p-∂Xv. sNºv Ipg-ep-Iƒ BsW-¶n¬ Xn≥ hmƒ ssS∏v (Thinwall type) aXn-bmIpw. sNºp Ipg-ep-Iƒ Ce-Itv Sm-tπ‰v sNøp-∂Xv \∂mbncn-°pw. sNºp-Ip-g-ep-Iƒ°v Xmc-X-tay\ hne IqSp-X-em-bn-cn-°p-sa-∂-Xn\m¬ Aeq-an-\nbw Ipg-ep-Iƒ D]-tbm-Kn-°mw. Aeq-an-\nbw Ipg-

IrXyw 280 sk. an. \of-ap≈ 9 mm As√-¶n¬ 3b8 C©v Aeq-an-\nbw Ipg¬ sIm≠mWv CXn-\p-th-≠n-bp≈ B‚n\m \n¿Ωn-t°-≠-Xv. Cu Ipg-ens\ ka-N-Xp-cm-Ir-Xn-bn¬ aS-°-Ww. At∏mƒ Hmtcm hihpw 70 sk.-an. \ofw hcp-sa∂p ImWmw. F∂m¬ B‚n-\-bpsS ^oUv t]mbn‚ v (^oU¿ hb¿ IW-IvSv sNtø≠ ÿew) Hcp hi-Øns‚ a≤y-`m-K-Ømbn htc-≠-Xp≠v. AXn-\m¬ Xmsg-s°m-Sp-Øn-cn-°p∂ Af-hp-Iƒ Aep-an-\nbw Ipg-en¬ am¿°¿ sIm≠v AS-bm-fs - ∏-Sp-Øn-bn´v hf-b° v p-∂X - mWv \√-X.v Hc-{KØv \n∂pw 35 sk. an. AS-bm-f-s∏-Sp-Øp-I. AhnsS \n∂pw 70 sk. an AS-bm-f-s∏-Sp-Øp-I. XpS¿∂v c≠v 70 sk. an. AS-bm-f-s∏-Sp-Øp-I. _m°n-bp≈ `mK-Øn\v 35 sk. an. Bbncn°pw \ofw.

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AdnbmØXv F∂pw. At∏mƒ Dxing \v AdnbmØ Zqcw F∂ A¿∞w e`n°p∂p. F^v. Fw. tdUntbm Dxing efnXamb am¿§ßƒ 1.

sk≥kn‰nhn‰n IqSnb dnkohdpIƒ D]tbmKn°pI F∂XmWv G‰hpw efnXamb am¿§w, Im¿ ÃocntbmIfmWv G‰hpw sk≥kn‰nhn‰n D≈ F^v.Fw. tdUntbm sk£\pIƒ ASßnbncn°p∂Xv AXn\m¬ Im¿ÃocntbmIƒ ho´n¬ D]tbmKn®m¬ sa®s∏´ coXnbn¬ F^v.Fw. {ihn°mw.

2.

Kmßv I¨≥k¿ F∂ SyqWnwKv kwhn[m\ap≈ tdUntbmIƒ D]tbmKn°pI. kvIm\nwKv tdUntbmIƒ°v km[mcWKXnbn¬ sk≥kn‰nhn‰n Ipdhmbncn°pw.

3.

ho´n¬ \nehn¬ sSenhnj≥ B‚ n\Iƒ D]tbmKn°p∂ps≠¶n¬ AXn¬ \n∂v Hcp hb¿ IWIvSv sNbvXv tdUntbmbpsS Gcnbepambn _‘n∏n°pI.

4.

sa‰¬ t_mIvkn¬ Akw_nƒ sNbvXv Hmt´mdn£Iƒ, _kpIƒ XpSßnb hml\ßfn¬ ^n‰v sNøp∂Xn \mbn e`n°p∂ Xcw sU¬ln tdUntbmIƒ D]tbmKn°pI. CØcw tdUntbm hmßptºmƒ tkmWn, ^nen]vkv, XpSßnb Iº\n IC D≈h hmßcpXv, ssN\m IC D≈h Xs∂ thWsa∂v IS°mct\mSv {]tXyIw ]d™v hmßWw. \njn° CeIvt{SmWnIvkv sU¬ln CØcw sslsk≥kn‰n hn‰n dnkohdpIƒ \n¿Ωn°p∂p≠v.

5.

]gbXcw F^v.Fw. tdUntbmIƒ D]tbmKn°pI. Ct∏mƒ hcp∂ F^v.Fw. tdUntbmIfn¬ IF sk£≥ F∂ SyqWnwKv hn`mKw IC IfmWv ssIImcyw sNøp∂Xv.

A{Kw tkmƒU¿ sNøp∂Xn\pw, ]‰p∂XcØnep≈XmWv. {Sm≥kv t ^m¿adpIfn¬ \n∂pw tNkn nte°v IWIv S v sNøp∂Xn\pw Hmt´msamss_epIfnepw CXv D]tbmKn°p∂p≠v.) Chbn¬ H∂ns‚ A{KØn¬ tIm˛BIvknb¬ tI_nfns‚ tImdpw at‰Xns‚ A{KØn¬ jo¬Upw tkmƒU¿ sNbøWw. bmKn B‚n\mbnset∏mse \´pw t_mƒ´pw D]tbmKn®v ^oU¿ hb¿ IWIvSp sNbvXm¬ t]mcm. tkmƒU¿ sNøpI Xs∂ thWw. tIm˛BIvknb¬ tI_nfns‚ at‰ A‰Øv Snhn, B‚ n\ tkm°‰n¬ IpØp∂Xn\mbn Hcp ]n∂n¬ IWIvSp sNøWw. IzmUv B‚ n\m kwt{]£Ww sNøp∂ tÃjs‚ B‚n\mbv°v A`napJambn thWw {^n©v Gcnbbn¬ 10 ao‰¿ DbcØnse¶nepw Cu B‚n\ ^n‰v sNøm≥ {ian°pI. Cu B‚ n\tbmsSm∏w _qÿ D]tbmKnt°≠ Bhiyan√. D]tbmKnt°≠ Bhiyan√. D]tbmKn°pIbmsW¶nev 75 Hmwkv C≥]p´v / Hu´v ] p´v Cw]U≥kp≈ _qÿ Xs∂ D]tbmKn°Ww. DZmlcWw more FM Ãocntbm _qÿ.

F^v.Fw. kn·epIfpsS k©mc]Yw t\¿tcJbn¬ am{Xta k©cn°pIbp≈q F∂ F^v.Fw. tdUntbm XcwKßfpsS {]tXyIX ImcWw F{Xi‡nIqSnb {Sm≥kvan‰¿ D]tbmKn®mepw `qanbpsS I¿th®¿aqew 50 Intemao‰¿ ZqcØnepw A∏pdtØ°v Hcp F^v.Fw. tÃj\nse {]t£]Ww FØpI F∂Xv Xnbdn‰n°embn {]mtbmKnIa√. kkyeXmZnIƒ F^v.Fw. kn·epIsf \∂mbn BKncWw sNøpw F∂Xpw, Ip∂pw, aebpw, Xmgvhmcßfpw \nd™ tIcfØns‚ `q{]IrXnbpw Cu 50 Intemao‰¿ F∂ Zqc]cn[nsb ho≠pw Ipdbv°p∂p. Aßs\ hcptºmƒ Hcp F^v.Fw. tdUntbm kvt‰j\n¬ \n∂pap≈ {]t£]Ww km[mcW

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B‚ n\Iƒ D]tbmKn®v kzoIcn°mhp∂ ]cn[n 25˛30 Intemao‰dpIƒ am{Xambn Npcpßp∂p.

Nn{Xw 1 t\m°pI F^v.Fw. tdUntbm tÃj\n¬ \n∂v 50 Intemao‰¿ Ign™m¬ F^v.Fw. kn·epIƒ e`yamsW¶n¬ t]mepw AXv iq\ymImiØnte°v \jvSamhpIbmsW∂v ImWmw. At∏mƒ Nn{Xw 1 se hoSv F.bn¬ F^v.Fw. tÃj≥ e`yamhWsa¶n¬ hoSn\v apIfn¬ Hcp B‚n\ ÿm]n®m¬ aXnbmIp∂XmWv.

aeIfpw, Ip∂pIfpw, ^vfm‰v kap®bßfpw F^v.Fw. kn·epIsf XS s∏SpØp∂p. hoSv F˛bnepw _n˛bnepw D≈h¿°v F^v.Fw. tdUntbm {ihWw _p≤napt´dnbXmbn amdnbnbncn°p∂p. Nn{Xw 3 t\m°pI. hoSv F, _n. F∂nhSßfnse Xmak°m¿°v \√coXnbn¬ \n¿Ωn® F^v.Fw. B‚n\ D]tbmKnt°≠nhcpw.

F^v.Fw. tdUntbm Dxing hnZqcXbn¬ \n∂p≈ F^v.Fw. tÃj\pIƒ tIƒ°pI F∂Xv Hcp hyXykv X amb tlm_nbmWv . temIØns‚ hnhn[`mKßfn¬ CXpt]mep≈hcpsS Iq´mbva ¢∫pIƒ {]h¿Øn°p∂p. hmcm¥yßfn¬ GsX¶nepw aeapIfn¬ HØv IqSn X߃ \n¿Ωn® D]IcW߃ D]tbmKn®v hfsc hnZqcXbn¬ \n∂p≈ F^v.Fw. tÃj\pIƒ {ihn®v IqSpX¬ tÃj\pIƒ°mbn XßfpsS D]IcW߃ Syq¨ sNbvXpsIm≠ncn°pw CØc°m¿. hnZqcXbn¬ \n∂p≈ tdUntbm {]t£]W߃ kzoIcn°p∂Xns\bmWv tdUntbm Dxing F∂v ]dbp∂Xv. CXnse D F∂Xv Distance F∂Xns‚ Npcp°amWv X F∂m¬

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CXv \ap°v ]pdØv \n∂v Syq¨ sNøm≥ km[n°n√. ]gb F^v.Fw. tdUntbmIfnse IF sk£\pIƒ \ap°v Hcp Asse≥sa‚ v kv{Iq ssUh¿ D]tbmKn®v \∂mbn Syq¨ sNøm≥ km[n°pw. CXpaqew ho°mbn e`n°p∂ tdUntbm tÃjs‚ dnk]v£≥ \ap°v sa®s∏SpØm≥ km[n°pw.

tIƒhn-bpsS BtLm-j-ambn C\n F^v Fw XcwKw \jvS-s∏´ {]uUn-bn-te°v ]pXnb F^v Fw Xcw-K-ØneqsS Xncn®p \S-°p-Ib - mWv tdUn-tbm. kmt¶-XnI IpXn∏n¬ CSbv°v Fhn-sStbm ssItamiw h∂ knwlm-k\w Xncn-®p-]n-Sn-°m-\p≈ Ah-kc - amWv tdUn-tbm°v Hcp-ßnbn-cn-°p-∂-Xv. ap≥X-e-ap-d-bpsS Krlm-Xpc kvac-W-I-fn¬ \nd™p \n¬°pIbpw B[p-\n-IbpK-Øn¬ \ndw aßn-t∏m-Ip-Ibpw sNbvX tdUntbm-bpsS AXn-i-‡-amb Xncn-®p-h-c-hn\v km£yw hln-°m-s\m-cpßp-I-bmWv ]pXnb Imew. \jvS-s∏´ {]uUn-bn-te°v ]pXnb F^v Fw Xcw-K-Øn-eqsS Xncn®p \S-°p-I-bmWv tdUn-tbm. kmt¶-Xn-IIp-Xn-∏n¬ CSbv°v Fhn-sStbm sh®v \jvS-amb knwlm-k\w Xncn®p-]n-Sn-°m-\p≈ Ah-k-c-amWv tdUn-tbm°v Hcp-ßn-bn-cn-°p-∂-Xv.

6.

t]m¿´_nƒ sSenhnj\pIfn¬ D]tbmKn°p∂Xcw dm_n‰v Cb¿ sSenkvtIm∏nIv B‚n\ D]tbmKn°pI. CØcw B‚n\Iƒ AXns‚ BapIƒ Db¿Ønbpw XmgvØnbpw, s]mknj≥ am‰nbpw h®m¬ \√ dnk]v£≥ e`n°pw. sslsk≥kn‰hn‰n dnkohdpIƒs°m∏w D]tbmKn®m¬ \√ dnkƒ´v e`n°pw. 7.

^vfm‰v hb¿ D]tbmKn°pI B‚ n\bn¬ \n∂v tdUntbmbnte°v IW£≥ sImSp°m≥, ]gbIme ªm°v & ssh‰v sSenhnj≥ B‚n\ IWIvSv sNøm≥ D]tbmKn®ncp∂ dn_¨ tI_nƒ (^vfm‰v hb¿) D]tbmKn°pI. CXn\p]tbmKn °p∂ tI_nƒ \√ KpWta≥abp≈Xmbncn°Ww. hg°ap≈Xmbncn°Ww. (hfsc Ãn^mbncn°p∂h tamiw tIm∏¿ D]tbmKn®Xmbncn°pw)

tIc-fØ - nse BZy kzmImcy F^v Fw tÃj-\mb tdUntbm amwtKm 91.9 {]t£-]Ww XpSßn-b-tXmsS F^v. Fw tdUntbm cwKØv hnπ-h-I-c-amb am‰-Øn\pw a’-c-Øn\pw Ac-sßm-cp-ßp-I -bm-Wv. ae-bmf at\m-c-a-bpsS Cu F^v. Fw kwcw`w tImgn-t°mSv \K-c-Øn\v 50 Intem-ao-‰¿ Np‰-f-hn-ep≈ t{imXm-°ƒ°v e`y-am-hpw. tIc-fØ - n¬ {]h¿Ø-\m-\p-aXn e`n® 17 kzImcy F^v Fw tdUntbm tÃj-\p-I-fn¬ BZy-tØ-XmWv tdUntbm amwtKm.

8. k¨ s\‰vh¿°ns‚ tdUntbm {_m≥Umb 93.5 Fkv F^v Fw tImgn-t°m-Sp-\n∂v Unwkw-_¿ Ggv apX¬ {]t£-]Ww XpSßn°-gn-™p. sslZ-cm-_m-Zv, _mw•q¿, Pbv]q¿, `qh-t\-iz¿, I´-°v, Xncp∏-Xn, eIv\u, t`m∏m¬ XpS-ßnb \K-c-ß-fn¬ XcwKw Xo¿Ø {_m≥UmWv 93.5 Fkv F^v Fw. C¥y-bnetßm-f-an-tßm-f-ap≈ 31

dm_n‰v Cb¿ B‚n\ D]tbmKn°pI.

\ofw BhiyØn\v am{Xw F^v.Fw. B‚ n\bn¬ \n∂v tdUntbmbnte°p≈ hbdns‚ \ofw BhiyØn\v am{Xta BImhq. Cu hb¿ Npcp´n hbv ° pItbm, \neØnSpItbm sNøp∂Xv dnk]v£≥ Izmfn‰n tamiam°pw.

14

15

9.

kn.Un., Un.hn.Un, Sn.hn., Iºyq´¿ apXembh {]h¿Øn°ptºmƒ F^v.Fw. dnk]v£≥ tamiambncn°pw. BbXn\m¬ C‚¿^nbd≥kv D≠m°p∂ D]IcW߃ Hm^v sNbvXnSpI.

10.

sshZypXn sse\pIfpsS ASnbn¬ B‚n\ ^n‰v sNøcpXv. sshZypXn sse\pIfpambn kpc£nXamb AIew ]men°pI.

F^v.Fw. ssUt]mƒ B‚n\ G‰hpw efnXamb Hcp hn`mKw B‚n\IfmWv ssUt]mƒ B‚n\Iƒ. 9 mm (3/8) Aepan\nbw ss]∏v D]tbmKn®v Ch \n¿Ωn°mw. (km[mcW FIvtÃW¬ Snhn B‚n\Ifn¬ hf™ BIrXnbn¬ ImWp∂XmWv ssUt]mƒ)

F^v.Fw. eq∏v B‚n\ 3/20 CeIv{Sn°¬ hb¿ D]tbmKn®v hfsc efnXambn \n¿Ωn°mhp∂ Hcn\w B‚n\bmWv eq∏v B‚n\. 88 apX¬ 108 MHz hscbp≈ F√m {^oIz≥knbpw H∂n®v e`yamIp∂ Hcp sshUv _m≥Uv B‚n\bmWnXv. AXn\m¬ \nßfpsS {]tZiØv e`yamIp∂ GXv tÃj\pw Cu B‚n\ D]tbmKn®v hyIyambn kzoIcn°mw. 70 sk.ao. \ofap≈ c≠v ]´nI IjW߃ Cu B‚n\ \n¿Ωn°m≥ BhiyamWv. Ch Nn{XØn¬ ImWp∂ coXnbn¬ t{Imkv tPmbn‚ v sNbvXv Dd∏n°pI. CXns\ amÃv F∂v hnfn°pw. Cßs\ \n¿Ωns®Sp°p∂ B‚n\ amÃn¬ H∂c C©ns‚ BWnIƒ Xdbv°pI. B‚ n\ \n¿Ωn°m≥ D]tbmKn°p∂ hb¿ ssKUv sNøp∂Xn\v th≠nbmWv BWn Xdbv°p∂Xv. Nn{XØn¬ hb¿ ^n‰v sNbvXncn°p∂ coXn

\∂mbn t\m°n a\ nem°nbXn\v tijw Ãm¿´v F∂ t]mbn‚nse BWnbn¬ sIm≠v h∂v Ahkm\n∏n°pI. Ãm¿´v F∂ t]mbn‚n¬ hb¿ ^n‰v sNøm≥ \Ωƒ D]tbmKn°p∂ 3/ 20 CeIv{Sn°¬ hbdns‚ A¬∏w C≥kptej≥ If™v BWnbn¬ \∂mbn ]ncn®v Dd∏n°mw. End t]mbn‚nepw Cßs\ sNøWw. B‚n\ \n¿ΩmWØn\v tijw Cu t]mbn‚pIƒ, B‚n\ tI_nfpambn tkmƒU¿ sNbvXv Dd∏n°mw. As√¶n¬ \∂mbn C≥kptej≥ tS∏v H´n®mepw aXn. sh≈w Cdßn eqkv tIm¨SmIvSv D≠mImXncn°m≥ th≠nbmWnXv. amÃnse hb¿ IS∂v t]mIp∂ a‰v ssKUnwKv BWnIfn¬ hb¿ sNºv Iºn D]tbmKn®v sI´n Dd∏n®m¬ aXnbmIp∂XmWv. B‚n\ \n¿Ωn°m\mbn GItZiw 31/2 ao‰¿ 3/20 hb¿ \ap°v BhiyamWv. BZyambn Cu hb¿ \√ shbneØv c≠v aq∂v aWn°q¿ hen®v sI´nbnSpI. NqSmIptºmƒ hb¿ henbpw. Cu hb¿ FSpØv DS≥Xs∂ amÃn¬ eq∏v sNøpI. End t]mbn‚n¬ FØnbXn\v tijw _m°nbp≈ hb¿ apdn®v IfbpI. shbneØn´v kok¨ sNømØ hb¿ D]tbmKn®v B‚n\ \n¿Ωn®m¬ shbnte¬°ptºmƒ B‚n\ hb¿ eqkmbn dnk]v£≥ tamiamIm≥ CSbp≠v. eq∏v B‚ n\ amÃn¬ \∂mbn hpUv ss{]adpw s]bn‚paSn°p∂Xv Zo¿LIme CuSv \n¬∏n\v BhiyamWv. Cu B‚n\bpsS X ASbmfØn\v ]n∂nembn GI ¢mºpIƒ Xd®v B‚n\ ss]∏n¬ Db¿Øn DbcØn¬ LSn∏n°mw.

20

CXn¬ ]m´p-Iƒ, kao-]-ÿ-e-ß-fnse aX-]-chpw cmjv{So-bhpw ˛kmwkv°m-cn-I-hp-amb NS-ßp-I-fpsS Adn-bn-∏p-Iƒ, ka-Im-enIw F∂t]- c n¬ hm¿Øm hni- I - e \w, B- t cm- K y- h n- h - c - ß ƒ AS- ß nb sl¬Øv Sn]vkv, Km-‘n-b≥ Nn¥-Iƒ ]¶p-sh-°p∂ Km‘n-t{]m{Kmw,- Xo-h≠n kabw XpS-ßn-b-h-bm-Wp-≈-Xv.- X-ß-fpsS kz¥w aoUnb- F∂ tXm∂¬ P\-߃°n-S-bn¬ hf¿Øn-sb-Sp-°m≥ sIm®n F^v.-Fw. \p Ign-™p. sImta-gvkvsse-tk-js‚ `mK-ambn h∂ t^m¨ ˛ C≥ t{]m{Km-ap-I-fnse A\u¨k¿amtcmSv kz¥w {]iv\߃ IpSpw-_-Ønse H-cw-K-Øn-t\m-sS∂ \ne-bn¬ t{]£-I¿ ]¶psh-°m-dp-≠-t{X. kzmImcy F^v.-Fw. Nm\-ep-Iƒ h∂mepw P\-߃°v sIm®n\n-e-b-tØm-Sp≈ hnizm-kyX AXn\v apX¬°q-´mhpw. CXv Cu k¿°m¿ tÃj\v hfsc KpWw sNøp-Ibpw sNøpw. ]t£ BImi-hm-Wn-bpsS \yqkv Gsd sa®s∏Sp-tØ-≠-Xp-≠v. C\nbpw AXv s{]m^-j-W¬ Bbn-´n-√. Hcp-k¿°m¿ kYm-]-\-Øn\v kl-P-am-bn´p≈ \qem-am-e-I-fm-Wvt{]m-{Km-ap-Isf k¿§m-fl-I-am-°p-∂-Xn\v Ch¿°v XS- w. Ct∏gpw hbepw hoSpw, Ihn-Xm-]m-cm-bWw, ¢m-kn°¬ kw-KoXw XpS-ßnb ]cºcmKX ]cn-]m-Sn-If - n¬ IpSp-ßn-°nS°pI-bm-Wv. CØcw t{]m{Km-ap-Isf ssI-søm-gn-b-W-sa-∂-√. AXv \ne\n¬s° Xs∂ IqSp-X¬ anI® ]cn-]mSnIƒ \¬Ip∂ hn[-Øn¬ sshhn- [ y- h ¬°- c n- ° Wwhtc- ≠ - X p- ≠ v . km‰- s se‰v tdUntbm bmYm¿∞yambn- c n- ° p∂ C°m- e Øv , C¥y- b n¬ C{X- b - [ nIw B¿ss°hv k v tcJIƒ kq£n- ° p- ∂ BIm- i - h m- W n°v Hcp tdUntbm Nm\¬ km‰v-sse‰v aptJ\ XpS-ßm-hp-∂-Xm-Wv. Ct∏mƒ hy‡n-Iƒ apX¬ ÿm]-\-߃ hsc km‰-sse‰v tdUntbm XpS-ßnbn-´p-≠v. ]©m-_n-Iƒ°v am{X-ambn \S-Øp∂ ]©m_v tdUntbm CØ-c-Øn-ep-≈-Xm-Wv. amdnb kml-N-cy-Øn¬ BIm-hm-Wn-bpw a’c-Øn-\n-d-ßp-tºmƒ AXv ]ªnIv tdUntbm F∂ k¶¬∏sØ A´na-dn-°ptamsb∂v ImØn-cp-∂p-Im-W-Ww.

17

\K-c-ß-fn¬°qSn {]t£-]Ww hym]n-∏n-°m≥ Hcp-ßp-I-bmWv Fkv. F^v Fw. Gjy-s\-‰ns‚ s_Ãv F^v Fw 95 Xriq-cnepw IÆq-cnepw {]t£-]Ww Bcw-`n-®p. Kƒ^v \mSp-If - n¬ kzmIcy tdUntbm {]t£]-W-hn-π-h-Øn\v t\XrXzw \¬In Ct∏mƒ Xs∂ Gjy-s\‰v tdUntbm {]t£-]-W-Øn¬ kPo-h-am-Wv. kzImcy F^v. Fw tdUntbm tÃj-\p-I-fpsS hc-thmsS t{imXm-°ƒ°v tdUntbm ]pXnb A\p-`-h-ambn amdp-sa-∂mWv hnebn-cp-Ø-s∏-Sp-∂-Xv. Hcp ImeØv F√m hoSp-I-fn-tebpw km∂n-≤y-ambn-cp∂ tdUntbm AXn¬ Ihn™ kzm[o\w kao] `mhn-bn¬ t\Sp-sa-∂mWv ]pXnb s{S‚ v kqNn-∏n-°p-∂-Xv. bph-Xz-Øns‚ apJap-{Z-bmbn amdnb samss_¬ t^mWn¬ F^v.Fw e`y-am-hp∂p F∂Xv CXns‚ {]nbw Db¿Øpw. bm{Xm-th-f-I-fn¬ t{imXm-hns\ ]n≥XpS-cp∂ km∂n-≤y-ambn hml-\-ß-fnepw F^v Fw ÿm\w t\Sn-°gn™p. {^oIz≥kn tamUp-te-j≥ kmt¶-Xn-I-hn-Zy-bn-emWv ]pØ≥ tdUntbm A\p-`-h-Øns‚ \nZm-\w. tdUntbm \ne-b-Øn¬ \n∂v 40 apX¬ 100 hsc Intem-ao-‰¿ Np‰-f-hn¬ Cu coXn-bn¬ {]t£]Ww km[y- a m- h pw. 87.5 MHz \pw 108 MHz \pw CS- b n- e p≈ {^oIz≥knbmWv F^v Fw {]t£-]Ww kzoI-cn-°m\mhpI. XcwKssZ¿Lyw Ipd-hm-b-Xn-\m¬ a‰p XS- -߃ i_vZsØ kmc-ambn _m[n-°m-dn-√. AXp-sIm-≠pXs∂ F^v Fw {]t£-]Ww UnPn‰¬ hy‡-X-tbmsS e`y-am-hp-∂Xv. tdUntbm k¶¬∏-Øns‚ AXn-cp-Isf t`Zn-°p∂ {ihym\p-`-h-amWv F^v Fw ]I¿∂p \¬Ip-hm≥ Xøm-sd-Sp-°p-∂-Xv. \hkmt¶-XnI ]n≥_-e-tØm-sS-bmWv tdUn-tbm-bpsS ]pXp-X-cwKw IS-∂p-h-cp-∂-Xv. {]t£-]W Ie-bn¬ tdUntbm tPm°n-I-fpsS hmKvNm-Xp-cy-Øns‚ A\p-`-h-X-ehpw C\n bmYm¿∞y-am-hp-I-bmWv.

18

Xncp-h-\-¥-]p-cw, sIm®n, Xriq¿, tImgn-t°m-Sv, IÆq¿ F∂o A©v \K-c-ß-sf-bmWv tIc-f-Øn¬ 17 F^v Fw {^oIz≥kn-Iƒ A\p-h-Zn-°-s∏-´n-´p-≈-Xv. CXn¬ ae-bmf at\m-c-a, amXr-`q-an, k¨{Kq∏ns‚ Im¬ tdUntbm F∂nh \mev {^oIz≥kn-Iƒ hoXhpw Gjyms\-‰v, AUvem_vkv F∂nh c≠v {^oIz≥kn-Iƒ hoXhpw tdUntbm an¿®n Hcp {^oIz≥kn-bp-amWv kz¥-am-°n-bn-´p-≈-Xv. ae-bmf at\mca sIm®n, Xriq¿, tImgn-t°m-Sv, IÆq¿ F∂n-h-S-ß-fnepw amXr`qan Xncp-h-\-¥-]p-cw, sIm®n, Xriq¿, IÆq¿ F∂n-h-S-ß-fnepw F^v Fw tÃj-\p-Iƒ°p≈ ssek≥kv t\Sn-bn-´p-≠v. Xncp-h-\¥]p-cw, Xriq¿, tImgn-t°m-Sv, IÆq¿ F∂n-h-S-ß-fn¬ F^v Fw tÃj≥ XpS-ßm-\mWv Im¬ tdUntbm ssek≥kv t\Sn-b-Xv. Gjyms\-‰n\v Xriq¿, IÆq¿ F∂n-h-S-ß-fnepw F^v Fw \ne-b-߃ Bcw`n°m\mWv ssek≥kv e`n-®n-´p-≈-Xv. tdUntbm an¿®n°v Xncp-h-\¥-]p-c-ØmWv {]h¿Ø-\m-\p-aXn e`n-®-Xv. Ch-sb√mw bmYm¿∞yam-bm¬ tIcfw tIƒhn-bpsS BtLm-jØ - n-te°v IS-°p-sa∂v \nkwibw ]d-bmw.

C\n F^v Fw tdUn-tbm-Iƒ kuP-\y-ambpw kzImcy F^v Fw tÃj-\p-Iƒ C∂v tIcfw Iø-S-°m-\p≈ Hcp-°-Øn-em-Wv. 17-˛-Hmfw ÿm]-\-߃°v k¿∆okv XpS-ßm\p≈ A\p-aXn In´n-°-gn-™p. CXn-\n-S-bn¬ h¿j-ß-fmbn k¿°m-cn-s‚ ]cn-an-Xa - mb hn`-hß - f - n¬ \n∂p-sIm≠v Hcp tÃj≥ AXns‚ hnPbw ]d-bp-∂p-≠v. sIm®n-bnse F^v Fw tdUntbm tÃj≥ 1989 HIvtSm_¿ H∂n-\mWv CXv Bcw-`n-°p-∂-Xv. tIc-f-Øn¬ At∏m-gp-≠m-bn-cp∂ tdUn-tbm-\n-e-b-ß-sfm-s°bpw aoUnbw thhn-em-bn-cp-∂p. tÃj\p-I-sf-Xs∂ aq∂mbn Xncn-®n-´p-≠v. tem°¬, t\m¨--˛tem°¬, doPnb-W¬. CXn¬ IÆqcpw tZhn-Ip-fhpw t\m¨ ˛ tem°¬ BWv. tImgn- t °m- S v , Xncp- h - \ - ¥ - ] p- c w, Xriq¿ F∂nh doPn- b - W - e pw. sIm®nsb Hcn-°epw tem°¬ C\-Øn¬s∏Sp-tØ-≠-Xn-√. CXns\ tem°¬ B°n-b-tXmsS Xs∂ AXn-s‚ XpS°w ]m-fn. sIm®nbpsS Pntbm-˛s - ]m-fn-‰n-°¬ {]m[m\yw Chn-SpsØ cmjv{Sob {]h¿Ø-

19

Itcm a‰v A[n-Im-cn-Itfm Xncn-®-dn-bm-Ø-XmWv Imc-Ww. hfsc Ipd™ ^≠pw Ipd™ Ãm^p-IfpamWv sIm®n-°p-≠m-bn-cp-∂-Xv. sIm®n tÃj≥ Bcw-`n-°p-∂Xv ChnSpsØ ao≥]n-Sp-Ø-°msc D∂w sh®p-sIm-≠m-Wv. Hcp sNdnb ]cn-[n-°-IsØ Imcy-ß-ƒ am{Xw ssIImcyw sNøp-I. doPn-b-W¬, t\m¨˛tem-°¬ tÃj-\p-Iƒ°v KpW-ta-∑b - p≈ ÃpUn-tbm, a‰v C≥{^m-k{v S-IN - ¿ kuI-cy-߃ \¬Iptºmƒ tIc-f-Øns‚ hmWnPy Xe-ÿm-\-amb sIm®nsb A[n-IrX¿ Ah-K-Wn-®-Xn\vsd ^e-amWv \n m-c-amb hn`-h-ßfpw D]-I-cW-ßfpw am{Xw A\p-hZ- n®v sIm≠v Cu tÃj≥ XpS-ßn-bXpw C∂pw tem°¬ ]Z-hn-bn¬ Xs∂ XpS-cp-∂-Xpw. BZy-Im-e-ß-fn¬ H‰ {Sm≥kvan-js\ D≠m-bn-cp∂p≈p. sshIn´v 6 apX¬ 9.30 hsc. ]n∂oSv cmhnse 6 aX¬ 9 hscbpw {Sm≥kvan-j≥ XpS-ßn. tI{µ-Ønse A[n-Im-cn-Iƒ tem°≥ tÃj\v c≠v {Sm≥kvan-j≥ th≠ F∂ ImcWw ]d™v cmhn-e-tØXv d±v sNbvXp. ]s£ At∏m-tg°pw P\-ß-fpsS ssZ\w-Zn\ Imcy-ß-fn¬ AXn-{]-[m-\-amb ]¶v Cu tÃj≥ \n¿h-ln-®p-sIm-≠n-cp-∂p. bm{Xm-k-abw Adn-bp-∂Xv apX¬ kn\n-am-Km-\-߃ tIƒ°p-∂-Xp-h-sc-bp≈ Hcp taJe. P\-߃ Cu Xocp-am-\-Øn-s\-Xnsc i‡-amb {]t£m-`-߃ \S-Øn. CXn-s\Øp-S¿∂v ]gb ka-b-߃ ho≠pw ÿm]n-°p-Ibpw H∏w a[ym” {]t£-]-Whpw sIm≠p-h-cn-Ibpw sNbvXp. Aßs\ aqs∂-Æ-ambn {S≥kvan-j≥ ˛ {]`mXw, a-[ym-”w, kmbm-”w. tem°¬ Ãm‰kv D≈ tÃj≥ aq∂v {Sm≥kvan-j≥ \S-Øp-∂Xv C¥y-bn¬ Xs∂ A]q¿∆-am-Wv. IqSmsX sIm®n tÃj≥ AXns‚ {]h¿Ø-\-Ønse {]mK¤yw ]e-Xh - W - s - X-fn-bn-®n-´p-≠v. AJn-e- tI-cf tdUn-tbm- \mSI a-’-c-Øn¬ ]e XhW tÃj≥ H∂mw ÿm\w \ne\n¿Øn. Ch¿ D≠m-°n-s°m-Sp-°p∂ dh\yq hcp-am\w ]cn-K-Wn-°p-tºmƒ D∂-Xm[n-Im-cn-Iƒ°v CXns‚ tem°¬ ]Z-hn-I-f™v IqSp-X¬ Ãm^p-Isfbpw C≥{^m-kvs{S-®dpw kmt¶-XnI anI-hp≈ ÃpUn-tbmbpw A\ph-Zn-°m-hp-∂-Xm-Wv. cmhnse 6.55 apX¬ 8.30 aWn-hsc {]t£-]Ww sNøp∂ F^v.-Fw.-U-b-dn-bmWv Ch-cpsS hcp-am\ t{kmX- v.- P-\ßsf Chcpambn G‰hpw IqSp-X¬ ASp-∏n-°p-∂-Xp-amb t{]m{Kmw.

24

lm^v thhv ssUt]mƒ aXn-bm-Ip-sa-∂-Xn-\m¬ 3.1 = ao‰¿ 2 Cu \ofw hcp∂ Hcp 3/8 Aeq-an-\nbw ss]∏v FSpØv D≈n¬ aW¬ \nd®v km-h[m-\-Øn¬ hf-s®-Sp-°-Ww. As√-¶n¬ Hcp ]´nI IjW-Øn¬ Nn{XØn¬ ImWp∂Xp t]mse sSen-hn-j≥ B‚o\ IWIvSv sNøm≥ D]-tbm-Kn-°p∂ dn_¨ tI_nƒ ap≥]-d™ \ - o-fØ - n¬ apdn®v BWn-bS- n-®p-w Dd-∏n°mw. IW-£≥ t]mbn-‚ v XmgvhiØv hcp∂ hn[-Øn¬ thWw B‚n\ GI ss]∏v D]-tbm-Kn®v Db-c-Øn¬ Dd-∏n-t°-≠-Xm-Wv. CXn\mbn B‚n\ amkv‰n¬ GI ¢mºp-Iƒ GI ss]∏v Dd-∏n-°mw. eq∏v B‚n-\-bn¬ \n∂v tdUn-tbm-bn-te°v dn_¨ tI_nƒ D]-tbm-Kn®v IW-£≥ sImSp-°mw. B‚n\bpsS s]mkn-k-j≥ hyXymkw hcpØn IqSp-X¬tÃj-\p-I-fn¬ hy‡-ambn e`n-°p-∂ -Zn-i-bn¬ B‚n\ Dd-∏n-°p-I.

21

ae-bmf at\m-ca, k¨ Sn.-hn. _n ]n- F¬ XpS-ßnb am≤ya `oa≥am-scms° tIc-f-Ønse {]apJ \K-c-ß-fn¬ F^v.- Fw. tdUntbm {]t£-]Ww Bcw-`n-°p-∂-Xns‚ Hcp-°-߃ Ahkm\L-´Ønem-Wv. 2008 XpS-°-tØmsS Ch-cn¬ Nne-cpsS tÃj-\pIfpsS {]h¿Ø\w Bcw-`n-°pw. kz¥w F^v.Fw tdUntbm kt‰-j-\p-I-fpsS {]Nm-c-W-Øn\mbn Xß-fpsS tÃj≥am{Xw e`n-°-Ø-°-hn-[-Øn¬ tÃj≥ tem°p- sNbvX(a‰v tÃj-\p-Iƒ Syq¨ sNbvXv e`n-°mØ hn[-Øn¬ tem°v sNb-X) F^v.-Fw. tdUn-tbm-Iƒ kuP-\y-ambn t{imXm°ƒ°v \¬Im≥ Ch-cnse Hcp {]apJ Iº\n Xøm-sd-Sp-°p-∂-Xmbn clky tI{µßfn¬ \n∂v Ce-Ivt{Sm-WnIvkv tlm_o k¿Iyq-´n\v hnhcw e`n®p. Cu kvIq∏v hmb-\-°m-cp-ambn ]¶p-sh-°p∂-Xn¬ BÀm-Z-ap-≠v. ssN\-bn¬\n∂v Cd-°p-a-Xn-sNbvX UnPn-‰¬ F^v.Fw.- td-UntbmIƒ Ct∏mƒXs∂ 30 cq] apX¬ hne°v Fd-Wm-IpfØv e`n-°p-∂-Xn-\m¬ C°mcyw Nncn®v Xt≈≠ Imcy-an-√t√m!

ssUt]mƒ B‚n\ ssUt]mƒ B‚n\ am{Xw D]-tbm-Kn-°p-∂h - ¿ B‚n\ km[mcW ^n‰p-sN-øp∂ slmdn-tkm-≠¬ s]mkn-j-\n¬ \n∂pw hyXyÿ-ambn sh¿´n-°¬ s]mfm-cn-‰n-bn¬ ^n‰p sNbvXp t\m°q. hfsc hnZp-c-amb tÃj-\p-Iƒ \nß-fpsS tdUn-tbm-bn¬ e`n-°p-∂-Xp-ImWmw. (F.M _qÃ-dp-Iƒ D]-tbm-Kn°Ww.) sh¿´n°¬ s]mfm-cn-‰nbn¬ 10 apX¬ 20 Un{Kn-hsc A¬∏m¬∏w Sn¬‰v sNbvXv ssUt∏mƒ ^n‰v sNøp∂Xv dnk-]vj≥ tImfn-‰n-Iq´pw

FM ^o¬Uv kvs{SMvXv ao‰¿ hnZqc FM tÃj-\p-Iƒ Syq¨ sNøp-∂-Xn\v dxr am¿°v hfsc klm-b-amb Hcp k¿Iyq-´mWv C\n sImSp-°p-∂-Xv. CXnse ao‰dmbn A\-temKv aƒ´n ao‰¿ 250 ssat{Im Bºn-b¿ ske-£-\n-en´v D]-tbm-Kn°mw

FM Loop Antenna

22

23

ssUt]m-fns‚ \ofw =2.929 % x 95% =2.782 meter

tdUntbm amt¶m FM tdUntbm \µ-Ip-am¿ ae-bmf at\m-c-a-bpsS fm tdUntbm Nm\¬ tdUntbm amt¶m 91.9 saKm-sl-Uvkn¬ tImgn-t°mSv, IÆq¿, Xr»q¿, F∂nhnSßfn¬ {]t£]Ww Bcw`n®p. tÃj\n¬\n∂v 50 Intem-ao-‰¿ Np‰-f-hn¬ CXns‚ {]t£-]Ww e`n°pw {^n©v Gcn-bm-bn¬ \n∂v Cu FM Nm\¬ hy‡-ambn e`n-°p-∂-Xn-\p≈ B‚o-\m-bpsS \n¿ΩmW hnhc-߃ C\n -hn-h-cn-°p-∂p. hnZpc{]tZ-i-ß-fn¬ FM tÃj-\p-Iƒ hy‡-am-bn- e-`-n°p∂-Xn\v {]tXy-I-ambn Xøm-dm-°p∂ B‚o\-Iƒ hfsc {][m\ ]¶ph-ln-°p-∂p. GXv tÃjs‚bmtWm B‚o\ \ap°v \n¿Ωn-t°-≠Xv B tÃ-js‚ {^oIz≥kn Adn-™n-cn-°Ww. AXn\v tijw Xmsg sImSp-Øn-cn-°p∂ t^m¿ape A\p-k-cn®v B‚o\m ssUt]m-fns‚ \ofw I≠p-]n-Sn-°mw. 300(-tIm¨Ã‚ v) ssUt]mƒ \ofw ao‰-dn¬ = F ({^o-Iz≥kn)

Ct∏mƒ In´p∂Xv Ce-Iv{Sn-°¬ thhv seMvXv Bbn-cn-°pw. AXns‚ 95% Bbn-cn°pw. ^nkn-°¬ seMvXv AYhm ssUt]mfns‚ bYm¿∞-Øn-ep≈ \ofw DZm-lcWw sIm®n fm kt‰-j≥ {^oIz≥kn =102.4 #nk tÃj≥ Ce-Iv{Sn-°¬ thhv seMvXv =300 102.4 MHz

= 2.929 M

ChnsS e`n-®n-cn-°p-∂Xv ^pƒthhv ssUt]mƒ seMvXv BWv. F∂m¬ FM e`n°phm≥ lmhv thhv ssUt]mƒ BsW-¶nepw aXn. At∏mƒ lm^v thhv ssUt]m-fns‚ \ofw = 2.782 = 1.391 meter ssUt]mƒ B°n FSp-°p-∂-Xn\v Syq_n\p≈n¬ aW¬ \nd®v hf-s®-Sp-°m-hp∂XmWv. ssUt]mƒ hf-s®-Sp-°p-∂Xv XΩnep≈ AIew 3 As√-¶n¬ 4 C©v aXn-bmhpw. ssUt]m-fns‚ a eoUv `qan-bp-ambn hb¿sIm≠v _‘n-°-Ww. b eoUv tdUn-tbmbpsS sSen-kvtIm-∏n°v B‚n-\m-bn¬ sImSp-°p-I. ssUt]mƒ 10 meter Db-c-Øn¬ shbv°p-∂Xv hy‡-X-D-≠m-hm≥ klm-bn-°pw. AXp-t]mse Ub-d-£≥Xn-cn®v SyqWnwKv hyXym-k-s∏-Sp-Øm-hp-∂Xm-Wv. CXvt]mse Xs∂ \ap°v tdUntbm amt¶m B‚n-\-bpsS ssUt]mƒ \n¿Ωn-°mw. 300 91.9 MHz 3.26 x 95% ˛ 3.1 meter

.

=3.26 meter

28

25

Wv. c≠m-asØ am¿§-Øn¬ {]t£-]Ww sNtø≠ HmUntbm {^oIz≥kn-bpsS Bπn-‰yq-Un-ep-≠m-Ip∂ am‰-߃°-\pkrXambn am‰w Icn-b¿ {^oIz≥kn-bpsS {^oIz≥kn-bn-ep-≠m-Ip-∂p. CØcw tamUp-te-js\ {^oIz≥kn tamUn-te-j≥ AYhm FM F∂p-hn-fn°p-∂p. FM {Sm≥kvan-j≥ D]-tbm-Kn-°p-tºmƒ G‰hpw IqSp-X¬ knKn\¬ Sp t\mbvkv tdtjym (SNR) km[y-am-Wv F∂-Xn-\m¬ a‰v i_vZß-sfm∂pw CS-bn¬ IS-°msX hfsc sXfn™ iw_vZw e`n-°pw F∂-XmWv G‰hpw henb {]tXy-IX. sSen-hn-j≥ ]nIvN¿ sSen-ImÃv sNøp-hm≥ Bπn-‰yqUv tamUpte-j\pw i_vZw {]t£-]n-°m≥ {^oIz≥kn tamUp-te-j-\p-am-Wv D]-tbm-Kn-°p-∂-sX-∂p-IqSn Hm¿°p-a-t√m. bqtdm- ∏ nepw Ata- c n- ° - b nepw C¥y- b nepw FM t{_mUv Imkvddv _m≥Uv 88 MHZ to108 MHZ -B-Wv.

Ãocntbm FM B‚n\

]m¿´v enÃv tr-1 c 2570/2n918

c1 - 56 pf

d1-d2 in 60 c2,c3,c4,1kp r1-r5 220 em-250 ssat{Im-Bºv ao‰¿ r1- 270 r2 -47 k r3-1k5 - r4 180 r.vr1 4k7 {]osk‰v

FM. Booster hfsc ho°mb FM kn·-ep-Iƒ Hcp sNdnb ssl{^oIz≥kn {]o Bwπn-^-b¿ D]-tbm-Kn®v _qÃv sNbvXm¬ am{Xsa hy‡-ambn \ap°v {ihn-°m≥ km[yamIq. CXn\v D]-tbm-Kn-°mhp∂ hfsc efn-X-amS k¿Iyq-´mWv ChnsS sImSp-Øn-cn-°p-∂Xv Cu k¿Iyq-´ns‚ Pcb te Hu´pw H∏w \¬In-bn-cn-°p-∂Xv. sk¬^v I¨kv{SIv‰¿ am¿°v hfsc {]tbm-P\ {]Z-am-bn-cn°pw

26

27

tImbn¬ L2.22 tKPv C≥kp-te-‰Uv tIm∏¿ hb¿ D]-tbmKn®v 3 Np‰p-Iƒ 5 mm Ub-ao-‰-¿ B‚n\ C≥ ]p´n\pw Hu´v ]p´n\pw A\p-tbm-Py-amb tkm°-‰p-Iƒ D]-tbm-Kn-°p-I. _qÃ-dn-\p≈ ]h¿ ksπ \√ hÆw ^n¬‰¿ sNbvX sdKp-te-‰Uv dc Bbn-cn-°p-∂Xv DØ-a-am-bn-cn-°pw. 12 thmƒ´v UPS _m‰-dnbpw D]-tbm-Kn°mw. (k¿Iyq-´v) hnj-a-Xbpw CØcw {]t£-]-W-Øn¬ IqSpw. AXn-\m¬ HmUntbm {^oIz≥kn t\cn´p {]t£-]-W-Ø\v D]-tbm-Kn-°msX AXn¬ \n∂pw Db¿∂ Hcp {^oIz≥kn-bp-ambn Ie¿Øn {]t£]Ww sNøp-I-bm-Wv ]Xnhv.

]m¿´v enÃv c1 5pf ,c2, 12 pf c,3,12pf c4.01 vci,vc2 22pf trimmer ri 33k r2 330 r r3 1k5 L1 tImbn¬ 4Np-‰p-Iƒ 22 sws C≥kp-te-‰Uv tIm∏¿ hb¿ D]-tbm-Kn®v 5 mm Ub-ao-‰¿ (sP¬ t]\-bpsS hÆ-ap≈ do^n-√ns‚ ]pdsa Np‰n-sb-Sp-°mw.) F¿Øv sskUn¬ \n∂v H∂m-asØ Np‰ns‚ apIƒ `mKØv A¬∏w C≥kp-te-j≥ If™v AhnsS \n∂pw Sm∏nßv FSp°mw

Cßs\ Ie¿Øm≥ As√-¶n¬ s]mXn-bm-\mbn D]-tbmKn-°p∂ {^oIz≥knsb Imcn-b¿ {^oIz≥kn (carrier frequency) As√¶n¬ tdUntbm {^oIz≥kn (rf) F∂p hnfn-°p-∂p. Hcp tdUn-tbmtÃ-js‚ {^oIz≥kn Cu Icn-b¿ {^oIz≥kn Bbn-cn-°pw. Icn-b¿ {^oIz≥kn°v Bπn-‰yqUv (amplitude) {^oIz≥kn (freequenct) F∂nh at‰-sXmcp {^oIz≥kn-°p-ap-≈-Xp-t]mseXs∂ D≠m-bn-cn°pw. {]t£-]Ww sNtø≠ HmUn-tbm-{^o-Iz≥kn-bpsS Bwπn-‰yq-Unt\m {^oIz≥kn-°p-≈Xp t]mse Xs∂ D≠m-bn-cn°pw. {]t£-]Ww sNtø≠ HmUntbm {^oIz≥kn-bpsS Bπn-‰yq-Unt\m {^oIz≥knt°m A\p-kr-X-ambn Imcn-b¿ {^oIz≥kn°v am‰w hcpØns°m≠mWv Cu Ie¿Ø¬ AYhm s]mXnb¬ \S-°p-∂-Xv. Cu {]{In-bsb tamUp-te-j≥ F∂p hnfn-°p-∂p. CXv c≠v Xc-Øep-≠v. (1) (1) Bπn-‰yqUv tamUp-te-j≥ (A.M) (2) {^oIz≥kn tamUp-te-j≥ (F.M) {]t£]Ww sNtø≠ HmUntbm {^oIz≥kn-bpsS Bwπn‰yqUn¬ D≠m-Ip∂ am‰-߃°-\p-krX-ambn Imcn-b¿ {^oIz≥knbpsS Bπn-‰yq-Unepw am‰-ß-fp-≠m-Ip∂ Xc-Øn-ep≈ tamUp-tejs\ bmWv Bπn-‰yqUv tamUp-te-j≥ AYhm (A.M) F∂p hnfn-°p∂-Xv. Ct∏mƒ k¿∆ km[m-c-W-amb tamUp-te-j≥ am¿§w CXm-

32

FM Receivers Frequency modulation is used in radio broadcast in the bandwidth range from 88 MHz til 108 MHz. This range is being marked as “FM” on the band scales of the radio receivers, and the devices that are able to receive such signals are called the FM receivers. Radio broadcast transmitters are using the amplitude modulation on LW, MW and SW bandwidths. According to international treaties, each of the transmitters has a 9 kHz wide broadcasting channel, therefore making maximum frequency of the information being transferred fNFmax=4.5 kHz, according to the characteristics of the AM signal. To put it more simple, the highest frequency of the sound that can be heard from the loudspeaker of an AM receiver is 4.5 kHz, all above it will be simply truncated in the circuitry. Considering the speech itself, this isn’t so important since the most important components are located below these 4.5 kHz (during the telephone transfer, all the components above 3.2 kHz are being cut, and nobody is complaining). Things stand different, however, for the transfer of music. Music has much more sound components, with their frequencies spreading up to 15 kHz, so truncating them above 4.5 kHz does deteriorate the transmission quality. The radio-broadcast FM transmitter has a 250 kHz wide channel on its disposal, therefore allowing for the maximum frequency of the information (acc. to the characteristics of the FM signal) to be fNFmax=15 kHz. That means that music is being fully transferred and its quality is significantly better than in the case of the AM transfer. The FM transfer has some other advantages, perhaps the most significant of them being the possibility of eliminating various disturbances that are manifesting themselves as snapping, squeaking etc. The main disadvantage, however, is not the result of the frequency modulation itself, but rather of the fact that this method is being used on high frequencies, and that high-frequency electromagnetic waves behave themself as light, spreading themselves in straight line, not reflecting from the ionosphere etc. This is why obtaining this kind of radiolink requires optical visibility between the transmission and reception antennas, which is not the case for the links obtained on frequencies which

29

A¬∏w Nne-th-dp-sa-¶nepw FM tÃj-\n¬ \n∂pw Ipd-®pIqSn AI∂ ÿe-ß-fn¬t∏mepw FM ]cn-]m-Sn-Iƒ kzoI-cn-°p-∂Xn\v km[y-am-Ip∂ Hcp B‚n-\-bm-WnXv. IqSmsX FM Ãocntbm kzoI-c-W-Øn\v th≠n Unssk≥ sNø-s∏-´n-cn-°p∂ Cu B‚n\ `mhn-bnse kwKo-Xm-kzm-Z-\-Øn\v Hcp klmbn Bbncn-°pw. ]co£-Ws - a∂ \nebv°v CXv \n¿Ωn-®m¬ \nß-fpsS ÿe-Øn-\S- ptØm Aev∏w AI-etbm D≈ Ãocntbm FM tÃj≥ kzoI-cn-°m≥ Ignt™-°mw. FSpØp ]d-tb≠ as‰mcp {]tXy-IX Cu B‚n\ GsX¶nepw Hcp {]tXyI FM kvt‰j≥ am{Xw kzoI-cn-°m≥ kwhn-[m\w sNø-s∏-´n-´p-≈-X√ F∂-Xm-Wv. FM _m‚nse 88 MHz apX¬ 108 MHz hscbp≈ ]q¿Æ- a mb {^oIz≥kn- I ƒ kzoI- c n- ° m≥ th≠n Unssk≥ sNbvX-Xn-\m¬ FM _m‚nse GXv tÃj≥ kzoI-cn°m\pw CXp aXn-bmIpw FM, B‚n-\-I-fnepw TV B‚n-\-I-fnepap]tbm-Kn-°p∂ Aeq-an-\nbw Ipg¬ Cu B‚n\ \n¿Ωn-°p-∂X - n\v Bhiy-an√. (C-Øcw IpgepIƒ hf-bv°p-∂-Xn\pw apdn-°p-∂-Xn\psa√mw _p≤n-ap-´p≈ tPmen-bm-W-t√m.?) ]I-c-ambn ]e-I-°-jW-Øn¬ kv{IqsN-bvXp-d-∏n-®n-´p≈ I´n-bp≈ Aeq-an-\nbw t^mbn¬ BWv Fen-sa‚p-I-fmbn {]h¿Øn-∏n-°p-∂-Xv. Cu Fen-sa‚p-Isf XΩn¬ _‘n-∏-°m≥ 18 tKPv Aeq-an-\nbw Iºnbpw D]-tbm-Kn-°p-∂p.

\n¿ΩmWw H≥]-XcbSn \ofhpw c≠n©p hoXnbpw H-cn©p I\-hp-ap≈ aq∂p ]e-I-°-j-W-ß-fn¬ thWw Aeq-an-\nbw t^mbn¬ Dd-∏n°m≥ (]-eI °jvW-ß-fpsS hen∏w tI´v A¤p-X-s∏-tS-≠, -CX¬∏w henb B‚n\ Xs∂-bm-Wv. HmSn´ hoSp-I-fn¬ HmSp ]mIm≥ th≠n Igp-t°m-en¬ Xd-°p∂ ]´nI As√-¶n¬ ]´n-tbm¬ CXn\p th≠n D]-tbm-Kn-°mw. GsX-¶nepw ]mgv XSn-bpsS ]´nI Bbmepw aXn. CuSp \n¬°-W-sa-¶n¬ \√ XSn D]-tbm-Kn-°p-Itbm s]bn‚p sNbvXv kwc-£n-°pItbm thW-sa∂p am{Xw.

30

Aeq- a n- \ nbw t^mbn¬ Ac C©p hoXnbpw 54 C©v \ofhpap≈Xv Bdp IjWw thWw. Hmtcm ]´n-Ib - nepw c≠p-IjWw hoX-amWv Dd-∏n-t°-≠-Xv. ]´n-I-bpsS HØ-a-≤y-Øn¬ Hmtcm C©v AI-e-Øn¬ Ch Aeq-an-\nbw As√-¶n¬ {_mkv kv{Iq D]-tbmKn®v Dd-∏n-°pI. At∏mƒ Hcp-]´- n-Ib - nse c≠v Aeq-an-\nbw t^mbn¬ IjW-߃ XΩn¬ 2 C©v AI-e-߃ D≠m-bn-cn-°pw. 54 C©p \of-ap≈ t^mbn-ep-Iƒ°v tijw ]´n-I-bpsS c≠-‰Øpw aq∂v C©v hoXw shdpsX InS-°pw. Cßs\ aqs∂Æw Xøm-dm-°p-I. ]Xn-\m-dSn \of-ap≈ Hcp Aeq-an-\nbw Ipg¬ FSpØv CXn¬ Xøm-dm°n sh®n-cn-°p∂ aq∂v Fen-sa‚p-Ifpw U ¢mºv D]-tbm-Kn®v Dd-∏n-°p-I. Hc-‰-Ømbn BZysØ Fen-sa‚ v Dd-∏n® tijw B Fensa‚nse Aeq-an-\nbw t^mbn¬ \n∂pw IrXyw 64 C©v AI-eØn¬ c≠m-asØ Fen-sa‚nse Aeq-an-\nbw t^mbn¬ hc-Ø-°hn[w c≠m-aØ - Xpw ¢mºp-]t- bm-Kn®v Dd-∏n-°p-I. CXp t]mse Xs∂ c≠pw aq∂pw Fen-sa‚p-Iƒ XΩn¬ IrXyw 64 C©v AIew kq£n®p-sIm-≠v aq∂m-asØ Fen-sa‚pw ¢mºw sNøpI. XpS¿∂v aq∂v Fen-sa‚p-Ifpw XΩn¬ XΩn¬ Aeq-an-\nbw Iºn-sIm≠v C\n ]d-bp-∂X - p-t]mse _‘n-∏n-°W - w. BZysØ Fensa‚n¬ c≠n-©-I-e-Øn¬ c≠v Aeq-an-\nbw t^mbn¬ IjW-߃ Dd-∏n-®n-´p-≠t√m? CXn¬ H-sc-Æ-Øns‚ A{K-Øn¬ D≈ kv{Iq A¬∏-ambn Ab-®n´v AXn¬ 18 tKPv Aeq-an-\nbw Iºn-bpsS Hc‰w Np‰n-bn´v B kv{Iq ho≠pw Dd-∏n-°p-I. Nn{X-Øn¬ ImWp-∂-Xpt]mse Aeq-an-\nbw Iºn c≠m-asØ Fen-sa‚nse heXp hiØp≈ t^mbn-enepw XpS¿∂v aq∂m-asØ Fen-sa‚nse CS-Xp-h-iØp≈ t^mbn-enepw _‘n-∏n-°p-I. _m°n Iºn 40 C©p \ofØn¬ U BIr-Xn-bn¬ hf®v aq∂m-asØ Fen-sa‚ns‚ Iºn IWIvSp sNømØ t^mbnen¬ IW-IvSp-sN-øp-I. XpS¿∂v 2,1 F∂ Fensa‚nse Iºn IWIvSp sNømØ t^mbn-ep-I-fn¬ IqSn IWIvSpsNbvXp Iºn-bpsS IW-£≥ Ah-km-\n-∏n-°mw. Ct∏mƒ 1, 2 F∂o Fen-sa‚p-I-fpsS CSbv°pw c≠v aq∂v F∂o Fen-sa‚p-I-

31

fpsS CSbv°pw Iºn H∂n\p aosX H∂mbn t{Imkv sNøp-∂p≠v Cu t{Imkn-ßn¬ Iºn XΩn¬ kv]¿in-°msX t\m°-Ww. AXpt]mse Xs∂ Fen-sa‚p-Iƒ Dd-∏n-®n-cn-°p∂ Aeq-an-\nbw Ipg-enepw Iºn kv]¿in-°-cp-Xv. Cu B‚n-\-bn¬ \n∂pw FM tdUn-tbm-bn-te°p≈ IW£≥ eoUn\v Hcp 300 dn_¨ tI_nƒ D]-tbm-Kn-°-Ww. TV B‚n\-bn¬ \n∂pw TV bnte°v IWIvSp sNøp∂ AtX tI_nƒ Xs∂. CXv B‚n-\-bpsS U t]mse hf® `mKØv hf™ `mK-Øp-\n∂pw ]{¥-≠n©v AIsebmbn (A-s√-¶n¬ aq∂m-asØ Fen-sa‚n¬ \n∂pw 28 C©v AI-e-Øn¬ thWw IWIvSv sNøm≥. tI_n-fns‚ at‰ A{Kw tdUn-tbm-bpsS FM B‚n\m sS¿Ωn\-en¬ \¬Ip-I. ]m¿´v enÃv (]-´n-I-I-jvW-߃ ) H∂Xc ASn \ofw, c≠n©v hoXn. -3 FÆw Aeq-an-\nbw hb¿ Aeq-an-\nbw Ipg¬ k{Iq-Iƒ XpS-ßn-bh. (Aeqan\nbw t^mbn¬ ]gb I∏mkn‰dpIfn¬ \n∂v e`n°pw)

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33 FM Receiver with one Transistor and Audio Amplifier

are less than 40 MHz. In practical terms, it is possible to receive the SW signal from anywhere on Earth, whilst the range of an UHF link is limited to the horizon. Or, as Hamlet would say: “The quality or the range, that is the question!” Can we have it both, somehow? Yes we can, and it is already being done, over the satellite links, using the same equipment as for the TV signal receipt and an audio amplifier connected to the audio output of the satellite receiver. For now, in the earthly conditions, those that are interested in the worldwide news will make and use the AM receivers, and music lovers will stick to the FM’s. And what can those interested in both do? Well, they make AM-FM receivers :) The direct-type (TRF) FM receivers have never been produced, the industry started right away with the superheterodynes,In amateur life, however, the direct FM receivers do exist, having very simple electronic diagrams and being easy to manufacture. These receivers have very strong positive feedback, making the intermittent oscillations in it, and are therefore being called the super-reaction receivers.

The Simplest FM Receiver We have made this receiver on the experimental plate, and it was playing for days in our lab. Its electronic diagram is given on Pic.3.46. Regretfully we had to disassemble it, since we needed the plate for one of the devices described later in this book. This, too, is a reaction-type receiver, where the BF256 transistor, coil L and capacitors C, C* and C2 form the Hartley oscillator. Its frequency is being adjusted by means of the variable capacitor C to be equal to the frequency of the station that we wish to listen to. The LF signal is being taken from the R1 resistor, and led into the audio amplifier. * The coil L is self-supporting (doesn’t have the body), made of 5 quirks of CuL wire, its diameter being from 0.8 to 1 mm. It is spooled on some cylindrical object (pencil, pen etc., the best thing is the round part of a 9 mm drill), in one layer, quirks put tight to each other, as shown in the left, framed part of the picture. When the coil is finished, it is taken off the cylinder and stretched a little, so that the quirks do not touch each other. Its final length should be about 10 mm. The mid coil leg, which is to be connected

On Pic.3.43 you can se the electronic circuit of an extremely simple direct FM receiver. The T2 transistor together with the R1 resistor, the coil L the variable capacitor C and internal capacitances of the T1 transistor, comprises the so-called Kolpitz oscillator. The resonance frequency of this oscillator is being set by C to correspond to the one of the station that we wish to hear (meaning it has to be altered between 88 and 108 MHz). The signal, i.e. the information being used in the transmitter to perform the modulation, is extracted on the R1 resistor, and being led from it to the high-resistance headphones, over the coupling capacitor C1.

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The Simplest FM Receiver with Audio Amplifier The radio-broadcast FM transmitters operate with output power that is much smaller than that of the AM transmitters. That is why the LF signal coming from the device on Pic.3.43 is rather small, urging the use of very sensitive headphones. They are much more expensive than the “ordinary” ones, making it better to use the cheap headphones in connection with audio amplifier. One such solution where TDA7050 IC is used is given on the Pic.3.44. The R3 resistor and capacitors C5 and C6 are to be added only if the operation of the device is unstable. There optimum values are to be found experimentally, starting with those shown in the picture.

* The capacitance of the variable capacitor should be able to change from a couple of pF (Cmin) to app. 20 pF. During the testing off this device, we were using the capacitor from Pic.3.8. The legs marked as FO and G were used, the G leg being connected to the ground. When all the trimmers from the circuit on the Pic.3.8 are set to minimum capacitance, the capacitance between the FO and G legs should be adjustable between 7 and 27 pF. * The coil L has 4 quirks of lacquer-isolated copper wire (CuL), bended to have a 4 mm internal diameter. The practical realization of this coil is explained in text connected with Pic.4.9. During the setup of the bandwidth, the inductance of the coil can be altered by changing the distance between the quirks. If the coil is stretched the inductance decreases, and vice versa. If this cannot give the desired results, new coil must be made. * The telescopic antenna taken from a disused device can be used. If you can’t find one, you obtain very good results with a piece of isolated copper wire, about 60 cm long (the optimum length to be found experimentally).

For loudspeaker reproduction any of the previously described amplifiers can be used, e.g. that from Pic.3.21 (which we have been using, very successfully), or one of the devices described in P.E.4 and P.E.5. Since in these amplifiers a battery with voltage bigger than 3 V is used, using of R3 and C5 is obligatory. The R3 is counted from the formula where UBAT is battery voltage, and 0.235 mA is the current through R1, that supplies T1 and T2. E.g. if UBAT=9 V, it is then and the nearest existing resistor is used. Capacitors C5 and C6 comprise, together with R3, a pass-filter for very low frequencies, which is used to separate the HF and LF parts of the receiver. The battery itself acts as a short-circuit for the AC currents. But when it ages its resistance increases and there is no more short-circuit. That is why C3 and C4 are added, to accomplish it.

40 the oscillator, accomplish the reception of AM stations from all the bandwidths from 70 kHz till 200 MHz.

Superheterodyne FM Receivers The FM receivers being described in chapter 3.15 are the amateur solutions. These are extremely simple devices, that cannot perform the noiseless tuning, automatic oscillator frequency regulation and other features that ensure very high quality of the reproduction, being expected from an UHF FM receiver. The true solution is the superheterodyne FM receiver, whose block-diagram is given on Pic.4.6.Station signals are taken from the dipole antenna and led through the appropriate cable into the input circuit (UK). Inside it, the signal selection is performed, of station whose frequency is fS, this signal is then amplified in the HF amplifier and led into the mixer. As in the case of earlier described AM receiver, the inter-frequency signal is obtained at the mixer output, whose carrier frequency is fm=10.7 MHz (this is the standard value, used in all radio-broadcast FM receivers). The IF signal is being amplified in the IF amplifier and led on the amplitude limiter (Ogr.). In this stage the signal whose amplitude exceeds certain level is being cut off, accomplishing with this the elimination of the parasite amplitude modulation, which is performed by various noise sources during the transmission (atmospheric charges, various electrical devices etc.), which significantly improves the signal quality. The signal then goes to the FM signal detector, where the information being modulated in the transmitter is extrapolated from the signal, followed by the LF part of the receiver. With AFC the circuit that performs the automatic frequency regulation of the local oscillator is labelled

37 to the left end of the C3 capacitor, is made by taking off couple of millimetres of the lacquer from the wire, approximately in the middle of the coil. This place is then tinned and a piece of thin wire is soldered to it. The other end of this wire is soldered onto the PCB, on its place, to be connected to the left end of C2. * For the variable capacitor C the one from the Pic.3.8 (legs FO and G, G goes to Gnd). If you are using some other capacitor, that has bigger capacitance, and you cannot achieve the reception of the full FM bandwidth (88 til 108 MHz), try changing the value of the C*. Its capacitance is to be determined experimentally, usually being about a dozen pF.

* HFC is the high-frequency choke. Together with C2, it makes a filter that prevents the HF current to flow through the R1, simultaneously allowing for DC and LF current to go through. The muffler is, in fact, a coil that has 16 quirks of 0.6 mm CuL wire, spooled on a round part of a 3 mm drill. * This receiver works well even without the external antenna. It can, of course, be connected to it, as shown in dashed line. Instead of antenna, a 50 mm piece of wire can also be used.

FM Receiver with (just) one Transistor On the left side of the Pic.3.46 you can see the diagram of another very simple FM receiver, that has only one transistor as the active element. That is, as one can see, the HF part of the receiver from Pic.3.45, where

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the reproduction is being accomplished over the high-resistance headphones. But, as previously noticed, they are pretty expensive, therefore making it better to use the “regular” headphones and a simple amplifier, as shown on the right side of the Pic.3.46.

The Fully (not exactly 100%) Superheterodyne AM Receiver No.1 Its electrical diagram is given on Pic.4.4. It is easily being noticed that this is the receiver from Pic.4.2 with inter-frequency (IF) amplifier with ZN415E added. By adding ZN415 IC multiple enhancements are performed. Thanks to its huge input resistance, the MFT’s oscillatory circuit is not choked, resulting in better selectivity. The sensitivity of the device is extremely increased since this IC has big amplification and the AAR (automatic amplification regulation) is also accomplished, making the usage of this device easier and more comfortable.* It is very important to obtain the necessary value of the DC voltage in pin 6 of the ZN415 for its proper operation. Acc. to the table on Pic.3.36 it has to be about 1.3 V, and its setting is done via the TP1 trimmer. The receiver is set to some weaker station, the sound volume is made very low with potentiometer P, and the slider of the TP1 is carefully moved until the best reception is made. If that doesn’t work, one should try changing the value of R5 resistor; this is to be done also if the supply voltage being used is other than 12 V. In case of voltage on the pin being much bigger than 1.3 V, and cannot be reduced on the trimmer, short-circuit one of the diodes.* The voltage stabilizer with 78L06 isn’t needed if the receiver is supplied from the 6 V battery.* The receiver from Pic.4.2 needs input circuit to be 100% complete. That can be an independent input circuit from Pic.4.3i, or input circuit and the HF amplifier that are described in the Appendix (Pic.5.10). If the former circuit is used, station tuning is being accomplished with 2 knobs, as explained in the previous chapter.

Fully (not exactly 100%) Superheterodyne AM Receiver No.2 All the receivers we made with NE612 IC were tested in our lab, except the one from the previous project, since we didn’t have ZN415 “with us”. We found, however, a ZN414 IC, so we tested the receiver from Pic.4.5 with it. The receiver was working great, from the amateur’s point of view. He played us for long time, until we didn’t require the board to test one of the receivers from previous projects afterwards, when we regretfully had to disassemble it. * The diagram is very similar to that on Pic.4.4, so most of the things said about that receivers stands for this one, too.* DC voltage setting on pin 1 of ZN414 is done with the trimmer TP. Its slider is put in mid position, the receiver is tuned to some weaker station close to the upper bound of the bandwidth. While making the reproduction very quiet (slider of P as low as possible), the trimmer slider is moved until reaching optimum reception. After that the trimmer is disconnected, its resistance measured and the ordinary resistor of similar value is put into circuit. * The device operates nicely with the outside antenna made of a piece of wire measuring only half metres in length.* The reception would certainly become better if an input circuit would be added, which we spoke about in the previous project.* The receivers from pics. 4.4 and 4.5 can, with appropriate coils in

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capacitance of Cs should be reduced (to 15 pF, 10 pF etc.), or it should be short-circuited. You can also try compressing or stretching the L1 coil, etc. The setup of the oscillatory circuit is completed when with C=Cmax some station that operates on app. 88 MHz can be heard, and with C=Cmin the one that works on 108 MHz. The input circuit setup (it is connected between pins 13 and 14), is performed by tuning the receiver to some mid-range station (about 98 MHz). Then, the best possible reception is searched, by changing capacitances C13 and C12 and inductance L2.

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FM Receiver with TDA7000 The face that FM receivers operate on pretty high frequencies makes their practical realization somewhat difficult, but most of the problems, as in many other amateur builds, originates from building the coils, except the self-bearing, small-inductance coils (without the coil body), which are easy to make, especially if there aren’t many of them in the device and if no special instruments are required for setting up their proper inductance value. The coils used in this FM receiver are just like this, and there are only two of them, making the practical realization much easier.The basic data about the famous Philips’ IC used in this project, TDA7000, are given in the following table. Electronic diagram of the HF part of the device (from antenna to the LF output) built with TDA7000 is shown on Pic.4.7. As one can see, it is a simple device, made with relatively small number of components. The IC contains all the stages of the superheterodine receiver: the mixer, the oscillator, the IF amplifier, the amplitude limiter, the FM detector and few others. More about them will be told in the next project which contains the description for a receiver with TDA7088T IC, which is the improved version of TDA7000.The station signal is from the (telescopic) antenna led to the input circuit that consists of L2, C13, C12 and C14. It is a parallel oscillatory circuit damped with R3 resistor, which has the reception bandwidth from 88 MHz till 108 MHz (it admits all the UHF signals on the pin 13, and weakens te signals outside the reception bandwidth). Inside the IC the signals are led into the mixer, where they are being given new carrier frequencies. The IF amplifier then follows, amplifying only one of those signals, the one whose frequency is equal to the inter-frequency, followed by the limiter, the FM detector, mute circuit and LF pre-amplifier. The output from the last stage is on the pin 2 (R2 is the collector load of the last transistor in the LF preamplifier). The oscillatory circuit of the local oscillator (L1, Cp, Cs, C and C5) is connected between pins 5 and 6.Pic.4.8-a shows the PCB of the device from Pic.4.7, while Pic.4.8-b contains the component layout (on the PCB). The complete device can be seen on Pic.4.8-c. The variable capacitor from Pic.3.8 is used as the only variable capacitor here since the input circuit is aperiodic, the legs marked with FO and G. This capacitor serves us to tune the receiver to stations. In the LF part of the receiver, the amplifier

43 made with LM386 from Pic.3.19 is utilized (the components left from the potentiometer are omitted).* L1 and L2 are the self-bearing coils (without the core). They have few quirks and are made of relatively thick wire, therefore they don’t need a body of any kind, that is why they are called “self-bearing”. Their appearance is shown on Pic.4.9, and the calculus for them is done acc. to the table from Pic.3.5. They both have 6 quirks of the CuL wire, 0.6 mm in diameter, being spooled on the flat part of the 3 mm drill. In order to be able to solder the coil onto the PCB, the couple of mm of isolation has to be removed from the wire ends with sharp knife, and they have to be tinned afterwards. There must be a small gap between the adjacent quirks. The inductance of the coil is set by its shrinking (the inductance increases) or stretching (the inductance decreases). Stretching can be nicely done by inserting the screwdriver between the quirks and then turning it along the coil. * The TDA7000 also contains the mute circuit (for noiseless tuning). It is being active when the S2 switch is open. Pocket-type receivers usually do not have S2 and R1 elements.* The part of the receiver that requires biggest care during build is the oscillatory circuit of the local oscillator, which is connected between the pins 5 and 6. When changing the capacitance of C, its resonance frequency must change from 88 MHz (C=Cmax) till 108 MHz (C=Cmin). If that cannot be accomplished (not all the stations can be heard) some experimenting is required with capacitances of Cp and Cs. For start, you should omit the Cp. If the problem persists,

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Terminology y

Gain: amplification of the antenna (measured in dB)

y

dB: hey - if you don’t know this you are in the wrong article - but divide it by 3 for small numbers and this gives you the multiplcation factor for the signal

y

Attenuation: loss of the antenna or other component (measured in dB)

y

Polar Pattern: a “map” of the antenna’s sensitivity, as viewed from above. Polar patterns given here should be used as reference guides - the area enclosed by the line corresponds to a geographic area around the antenna. The size of that area differs depending on antenna gain, the height of the antenna, and the geography of the terrain.

y

Beamwidth: angle of directions for which the antenna is most sensitive

y

Adjacent channel / frequencies: FM frequencies occur on odd 200 kHz multiples, starting at 88.1 MHz and ending at 107.9 MHz. An adjacent channel (or frequency) is one 200 kHz away.

FM Receiver with TDA7088T IC The receiver described in the last project has two IC’s, one variable capacitor, two small coils and fairly small few other components, so it can be put into some small box, by carefully placing the components. Further miniaturization can be accomplished by using the SMD components. These are the resistors, capacitors, transistors, IC’s and other components, whose dimensions are significantly smaller than these of “classical” components. They are mounted on the copper side of the PCB, therefore it isn’t necessary to drill the holes on the board. TDA7088T is also an SMD component. Its drawing is shown on Pic.4.10.This IC is the successor of the famous TDA7000, i.e. it is an improved model of TDA7000, that allows to implement both monophonic and stereophonic FM receiver.

Omnidirectional Antennas Those listeners that find themselves in the middle of a metropolitan area, or very near to several nearby cities up to 30 or 40 miles away can benefit mostly from an omnidirectional antenna. This type of antenna will be of no help, however, if you are trying to receive a more distant, low power, or translator station. For these type of stations, a good directional antenna will be needed. Omnidirectional antennas come in two types: The “S” curve type and the “turnstile” type, shown below, along with their polar patterns. In the case of the omnidirectional antennas, the very name implies “from all directions eqaully”. The two antenna types have roughly circular polar

The electronic diagram of the HF part of the monophonic FM receiver made with TDA7088T IC is given on Pic.4.11. The IC contains all the parts of the classic superheterodyne receiver: the local oscillator, IF amplifier and FM detector, but also some other circuits that extend the possibilities and improve the features of this IC.As far as practical use is concerned, the most significant novelty is the auto-tuning circuitry. No variable capacitor is

46 necessary for tuning, as it was in all the previous projects, the BB910 varicap diode is used instead. Its capacitance is being changed by varying the DC voltage supplied to its anode over the 5k6 resistor. This is how the tuning is performed: When the user press and releases the pushbutton marked with “RUN”, the positive voltage impulse is released to the S(et) input of the SEARCH TUNING circuit. The 100 nF capacitor then starts chargingl and the voltage on the pin 16 increases. This voltage is then transferred, over the 5k6, to the anode of the BB910, causing its capacitance to decrease, which increases the frequency of the local oscillator (VCO). The VCO voltage is led into the mixer (MIXER) which also receives, over pin 11, the signals of all the other FM stations. The mixer outputs the FM signals whose frequencies are equal to the differences of the oscillator and the original station frequency. The only signal that can reach the demodulator (FM detector) is the one whose carrier frequency is equal to the inter-frequency, i.e. fm=73 kHz (selectivity is being accomplished by two active filters whose components are the capacitors connected to pins 6, 7, 8, 9 and 10). Therefore, the oscillator frequency increases until it gets the condition fO-fS=73 kHz is accomplished. When this happens, the charging of the capacitor is halted by the command that is sent into the SEARCH TUNING circuit by two detectors (diode-blocks) located in the MUTE circuit. The AFC (Automatic Frequency Control) circuit now gets its role and prevents the voltage on pin 16 to be changed, until the RUN button is pushed again (this voltage can vary from 0 V til 1.8 V during the tuning). When the RESET button is pushed, the 100 nF capacitor is discharged, the voltage on pin 16 drops down to zero, and the receiver is set to the low end of the reception bandwidth, i.e. 88 MHz.Let us get back to the mixer. On its output, the 73 kHz FM signal is obtained, and it is modulated by the programme of the first station that is found after the RUN button is pushed. This signal then passes the active filters, gets amplified in the IF amplifier (IF LIMITER) and passed onto the input of the demodulator. By connecting the demodulator exit, over the LOOP FILTER, the adder (+) and resistor, to the VCO, the so-called FFL (Frequency Feedback Loop) circuit is accomplished, reducing the deviations of the signal being received from ±75 kHz to ±15 kHz.The LF (AF) signal is led from the demodulator, over the LOOP FILTER stage, the invertor (-1) and MUTE circuit onto the pin 2. The detectors (diode-blocks) control the operation of the MUTE circuit, preventing the LF (AF) signal to reach the output pin (2) until the tuning on the station that creates the signal in the antenna that is strong enough for quality reception is obtained.

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FM Antennas This article relies heavily on the four part article: “What Kind of FM Antenna is Best for You?”, by Michael J. Salvatti, appearing in Audio Magazine January through April 1978 Although that article series is excellent, and contains a lot of very detailed information, it is now becoming somewhat dated, with many manufacturers mentioned going out of business, and others changing their product lines extensively and discontinuing specific models mentioned. Those who are curious can find the original article in libraries. This article is meant for FM listeners who are dissatisfied with the performance of the folded dipole antenna that came packaged with their receiver. Almost without exception, you will need to install an outdoor antenna. This article describes your options.

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Simple FM Loop Antenna Introduction Not everybody can afford elaborate aerials. Nor does everyone has the space for large aerial arrays. So how about an aerial which is small, inexpensive and, more importantly, actually performs well?For years I have been singing the praises of a simple aerial called an “FM Loop”. I often recommend this little antenna to newcomers to the hobby since they are very simple to construct, cost next to nothing and, more importantly, perform very well considering their simplicity. How well? A single 33 inch square (84cm) turn of coax typically has around 5.5 to 6dB gain on its own, which will compare very favourably to many 5 element yagis! 33 inches (84cm) is a quarter wave for the FM broadcast band but you could easily adapt the sizes to suit other bands. The loop is wideband and therefore suitable for the whole of the FM broadcast band and you can use it horizontally (coax feed point at the bottom) or vertically (coax feed point at the side).That’s right - it would often produce PI codes and PS names on my receiver’s display, but the loop was just fixed to the wall! So why aren’t more of us using these aerials? I don’t know! But I decided to put one to the test while out hilltopping one night. The resulting log was impressive to say conditions were as good as “flat” and the loop itself was only mounted around 8 feet above the ground, resting on a tree branch!The reason this article has been published is because the aforementioned log attracted a lot of interest and members wanted to know how to construct the FM loop to try out for themselves.The history bitThe FM loop is simply a single element cubical quad antenna. I have seen it described in other articles as “an excellent antenna”. Perhaps it would be simpler to compare its properties with those of the medium wave loop. It is of a slightly smaller size at band 2 frequencies but has the same figure-of-eight polar response and so receives both “front and back” (180 degrees apart) with side nulls 90 degrees in between. The side nulls are actually very deep. You can make this loop more directional by adding appropriately sized and positioned “reflector” and “director” loops as with a yagi though am only covering details of a single element loop for this article. As with all aerials, the best results will be achieved if it is mounted clear of objects, though this little gem actually still performs pretty well in confined spaces, indoors, and even leaning against a wall or stood

49 patterns. Neither type has gain (over a standard dipole), in fact, both types have a slight loss. This can be an advantage in areas where a lot of strong stations are available. If the antenna had too much gain, the received signals might overload your receiver, especially if it is older. The effect of placing the antenna higher than you could place a folded dipole will give you an effective gain, and is the main benefit from this type of antenna.

“S” Curve (folded dipole) Antenna and its Polar Pattern

Turnstile Antenna and its Polar Pattern

High Gain Directional Antennas A high gain directional antenna is needed for weak distant stations. Not only does it add gain, but its beamwidth can serve to reject other stations

50 on the same or adjacent frequencies - coming from directions outside the beamwidth. It can also reject sources of noise the same way. Noise can include reflections from nearby buildings or mountains, automobile ignition, large electrical installations or motors, or harmonics of CB and other types of communications. Directional antennas come in two basic types - Yagi and Log Periodic, and hybrids are possible. Yagi’s are recognized by elements that extend the entire width of the antenna, while log periodics are recognized by elements that alternate between sides of the antenna. Yagi’s tend to have higher gain and narrower beamwidths, while Log Periodics tend to have more uniform gain over the FM band and wider beamwidths. A generalization that applies to both types of antennas is that the larger they are (and the more elements they), the more gain and narrower beamwidth they will have. The reference above tends to favor log periodics, but I have found that large Yagi’s are an absolute necessity for really weak or distant stations (300 miles is possible but rare).

Polar Pattern for Yagi and Log Periodic Antennas Using TV Antennas Extreme caution is advised here, as FM reception from TV antennas is unpredictable at best. It requires the antenna manufacturer to extend the gain of the low VHF band (channels 2-6) from 88 to 108 MHz, which almost doubles the range. This is no small feat, and definitely involves compromising the performance for the low VHF TV channels - something that the antenna manufacturer may be unwilling to do. The majority of TV antennas simply roll off in gain through the FM band. Some have traps to eliminate FM reception, because FM can interfere with TV channel 6. These antennas may even have “break-off” elements to enable FM reception, so the user can make a choice.

MANDATORY SAFETY RULES! 1. Mount it so there is no possibility it could fall on power lines, or power lines on it.

51 2. Always use lightning arrestors. Even if you only get 2 inches of rainfall a year, it only takes one strike to destroy your equipment and/or kill you. Lightning arrestors will actually help you by bleeding off static electricity charges. 3. Strength and stability - mount it no higher than you can mount it securely! If not, the first high winds it encounters will turn it or blow it down. If you have carefully observed those safety rules - the rule for performance is: “The higher the better, within your budget and zoning limits.” In practice, though, a ten foot mast on top of your house will give satisfactory results. FM is line of sight, but there is usually enough reflection in the atmosphere to help you. Mid-afternoon is usually the worst time for distant FM, and that is the time where raw height will help the most. Every mile added to the line of sight comes at the expense of several feet of height, however. It may not be necessary to have line of sight, just line of sight to a region where the signal is more receivable. In cases where you are trying to receive a very weak station in a metropolitan environment, you may be able to see the tower. Although it is usually best to aim straight at the tower, there may be cases where it is necessary to aim the antenna to reject interfering signals. both Yagis and Log Periodics are least sensitive to signals broadside to them. This is intuitive, because the receiving elements present the smallest surface area on the sides of the antenna. It may be necessary to broadside your antenna to an interfering station, even if you are aiming way off of the desired signal. In rare cases, it is better to aim the antenna at a building or mountain to pick up the reflection of a station instead of the station itself. This happens when the building is relatively near and the station is several miles away. If you aim at the station, the reflection from the building causes multipath. If you aim at the building, you get the reflection, and the station - miles away - is rejected, eliminating the multipath.

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COMMON FM RADIO RECEPTION PROBLEMS Hissing If your radio hisses it could be because it is receiving a weak signal. This happens because radio receivers need reasonably strong signals to decode the stereo component of an FM signal. A weak signal can be caused if you are too far from a transmitter as well as large buildings or hills blocking the signal path. A good quality VHF Band 2 outdoor antenna correctly positioned to pick up the best signal will usually always improve FM reception. If necessary, a VHF Band 2 amplifier can be fitted to the antenna to boost a weak signal as well. If the radio is portable with no provision for plugging in an external aerial, listeners should try adjusting the position of the radio’s own antenna to improve the reception. Alternatively, moving the receiver to somewhere else in the STAR 104.5FM: HOW TO FIX YOUR FM RADIO RECEPTION DIFFICULTIES room may help particularly as FM reception can vary a great deal over short distances. Radio reception is often better near windows or upstairs rather than downstairs.

Distorted “S” Sounds on FM Radio This phenomenon is known as “Multi-path Distortion.” Multi-path distortion is characterised by sibilance which is the distortion of ’s’ and ‘z’ sounds used in speech to ‘shhhhh’ sounds. It is caused by the transmitted

up on the ground. Because of it’s characteristics it is not easily detuned by being close to nearby objects.The construction bitThis aerial uses Bodgitt & Scarper technology. It is so simple even I knocked one up in a matter of minutes. You don’t need to rely on my design, however, you may wish to make the construction a lot more sturdy, but the purpose of this article is to show how you can achieve good results with the simplest of constructional effort. If you are going to use the loop externally for an extended length of time you would need to give it more strength. I constructed the loop quickly to use in mobile situations where I just throw the loop up into a tree or hang it on a branch. I will get round to constructing something more solid one day - perhaps! This is what I used ...* Square wooden dowelling around 2cm thick (around half an inch). Enough for four x 84cm lengths = 336cm total (or 4 x 33 inch lengths = 132 inches total). half an inch square).* At least 15 metres (50 feet) of good quality 75 ohm coax cable* Screw terminal blocks* Sticky tape - duct / gaffer variety Alternatively, you could construct the loop out of plumbers copper pipe instead of coax and some 90 degree corner joints. Make sure you insulate the copper though with thick tape though if you intend to hang the loop on tree branches. Any physical contact *may* degrade performance.The receiving element itself is a 33 inch 84cm square loop of the coax, so you will need to construct a suitably sized wooden frame, say 10mm (half an inch) less each side of the wooden dowelling around which you will wrap the coax - this is to make allowances for the coax which will then be the correct size. The coax needs to have a feed point half way along the bottom of the frame so cut coax to a 336cm (11 feet) length and wrap this around the frame ensuring the inner core and outer (braid) are connected together, each end going into separate connections on a small electrical screw terminal block. The remainder of the coax will be used for the downlead - you can vary the length accordingly. Connect the two ends of the loop to either side of the coax downlead via the terminal block, either way around, it doesn’t matter.The impedance of the FM Loop is 75 ohms. There has been much debate about this but this is stated in ARRL and RSGB information. Also, recent computer modelling has given the impedance as 75 ohms at resonance too. The loop should be positioned broadside to the transmitter for best pick-up, while the nulls can be found endways on. The loop also seems to have other quirky attributes, exhibiting a slightly unidirectional pattern at times, but these quirks can be of great use.So, in conclusion, this is aerial is very easy to

54 construct. It is very efficient and seriously outperforms my FM whip with several extra dB of signal. As I have said, this loop has a big advantage in that it works well indoors and doesn’t seem to mind too much where it is located, making it an ideal aerial for beginners or those with no room or availability for roof mounted antennas. It doesn’t look like much af a DX aerial but I have been very surprised by its performance and it has become an essential part of my mobile DX setup. Used indoors at home I have been able to eliminate Lincs FM on 102.2 and leave Galaxy from Birmingham at noise-free listenable strength - something none of my other yagis or rooftop beams have ever been able to achieve.

FM Dipole for 88-108 MHz A simple dipole antenna can be used for improved reception of FM broadcast signals. A dipole is basically a length of conductor (wire) split into two portions and signal is taken off at the split. It has a nominal 3 dB gain over an isotropic source and is directional, tending to favor signals coming broadside to the wire. The dipole is customarily an electrical half wavelength of wire at the frequency of interest, since the impedance under this condition is

55

theoretically 72 ohms resistive and is a good match to a 50-75 ohm source or load generally presented by interfacing equipment such as receivers and transmitters designed to work into this range of impedances. The length of a half wave dipole in feet is calculated as 468 divided by the frequency in MHz or in inches as 5606/F mhz. This takes “end effect” into consideration, and also the fact that the dipole elements are of finite thickness, and works out as pretty close in practice. Therefore, a dipole for 98 MHz which is band center of the FM broadcast band, works out to 4.78 feet or 57.3 inches. The dipole would then consist of two lengths of wire each 2.39 feet or 28.65 inches long, arranged as shown in the figure. Coaxial cable can be used to connect to the antenna as shown, but for best results, a balun should be used to prevent feedline radiation or pickup, which tends to distort the pattern. For 88-108 MHz this can be made by winding the coaxial feedline through a toroidal core or around a ferrite rod. The idea is to insert a series impedance to shield currents on the outside of the outer conductor, effectively decoupling it from the antenna. The current inside the line does not see this, as the inner and outer conductors are carrying equal and opposite currents and produce no external magnetic field, so no loss is experienced. The ferrite can be almost anything that yields a high impedance at the operating frequency. For 88 MHz to 108 MHz, this can be a small toroid or rod with 3 to 4 turns of the cable. See Figure. We used a ferroxcube 768T188-4C4 material specified for 1 to 20 MHz, wound with 3 turns of RG 174/U miniature coax. The measured loss was 0.3 dB including two connectors in the test setup, and the impedance across the toroid effectively in series with the outer surface of the shield was 1100 ohms shunted by -1.2 pf as read on a Boonton RX meter. This is over 10 times the feedline impedance and should be adequate. The antenna should be mounted high and in the clear for very best results (30 feet away from anything else) and oriented facing favored direction of reception.

60

57

Interference Car radios should be relatively immune to ignition and other electrical interference from the vehicle, but failure of the vehicle’s electronic suppression equipment can cause crackles and interference or:

signal traveling to the listener’s radio receiver by more than one path. This is usually caused by the signal being reflected off hills or tall buildings. The reflected signal arrives at the receiving antenna a moment later than the direct signal because it has traveled further. The reflected and direct signals then interfere with each other causing the distortion.

•

Rhythmic ticking varying with engine speed

•

Whining varying in pitch with engine speed

•

Regular crackling associated with a car heater or the windscreen

transmitter and reject signals that arrive at the back or side of the antenna.

wipers/washers

It is also sometimes possible to mount the antenna so that a building screens

In most cases, a reputable auto electrician can fix this sort of interference.

Car Antennas Car radio antennas are always located externally and are usually a telescopic rod, although there are a number of cars fitted with heated rear window antennas or stubby helical wound antennas. To get the best from a car radio: • The antennas should be as high as possible, preferably on the roof and

The best way to minimise multi-path distortion is to use a directional rooftop FM antenna which will only pick up signals coming directly from the

it from the reflections but not from the wanted signal. If multi-path distortion is affecting a portable FM radio, try moving it to a different position in the room.

Adjacent FM Channels Adjacent channel interference is caused by an FM station which is close in frequency to the station being listened to. It can sound like a twittering noise in the background. This problem is usually only apparent on FM stereo but if the interfering station is very close in frequency, ie. only 50 or 100 kHz away, the effect may also be heard in mono.

away from the engine • Telescopic antennas should be fully extended

GETTING THE BEST FM RADIO RECEPTION

• The antenna should not be folded back onto the roof and kept well clear

AT HOME

of the bodywork

•

• Antennas should be of the correct length - around 80 cm is ideal. Antennas much shorter or longer than this may provide inferior results.

Make sure the antenna is suitable for receiving FM radio and is pointing in the direction of the radio transmitter at Somersby in Gosford.

•

Check that the antenna cable and connections are in good condition.

58 •

59 If possible swap another radio for the affected one. If the radio reception improves, there is likely to be an equipment problem with the first radio - check the antenna.

•

External FM Antenna The best quality FM radio receiver system consists of an FM antenna, permanently erected externally. As FM radio signals occupy the

Sometimes the TV antenna is used for both the TV and FM radio. If

same frequency band as some VHF television signals an FM antenna is

this is the case, remove the TV connection leaving only the direct

very much like a VHF television antenna. A VHF television antenna designed

cable between STAR 104.5FM:

to receive Band 2 TV channels may be used to improve FM radio reception.

HOW TO FIX YOUR FM RADIO RECEPTION DIFFICULTIES the antenna and radio. Listeners should also note that FM radio signals travel in almost straight lines and are unable to travel over or penetrate large obstructions. This usually means that parts of a coverage area may have a weak signal particularly in hilly terrain or highly built up urban areas.

FM Dipole Antenna The FM dipole antenna is economical and relatively simple to install, whilst offering a considerable increase in reception quality. An FM dipole antenna is built from TV ribbon cable, which is often supplied with hi-fi tuners or can be purchased from an electronics store.

A professional antenna installer can split the cable from the TV antenna and then run separate cables to the TV and FM receivers. If a splitter device is used, the signal strength is reduced. In some cases, particularly in low signal strength areas, an amplifier may also be needed. An amplifier boosts the signal and ensures that adequate signal strengths are supplied to both the radio and the television set.

GETTING THE BEST FROM YOUR CAR RADIO The metal bodywork of a vehicle prevents signals reaching the radio, so a quality external antenna is needed for good reception. FM radio reception can be difficult when traveling in built-up areas

The length of the dipole antenna should be approximately 1.5m long and is

or in undulating terrain. Multi-path distortion or a weak signals may be

constructed by connecting the ribbon cable to the radio receiver. The dipole

experienced. STAR 104.5FM: HOW TO FIX YOUR FM RADIO RECEPTION

antenna can be erected by attaching the cable to a wall with the 1.5m

DIFFICULTIES

section of the cable positioned horizontally where the best signal is found. This antenna can be rotated to find the best position to further optimise reception.

However, FM radio generally gives good results with quality sound and the option for stereo reception.

64

61

Frequency Transmitter State / (MHz) Power (kW)

Location

Station

90.4

0.05

Maharashtra

Pune

Radio FTII (Film & Television Instiute of India)

90.4

0.05

Pondicherry

Madagadipet

NILA FM (Sri Manakula Vidyanagar

90.4

0.05

Punjab

Ludhiana

Guru Nanak Girls’ College FM Radio Station

90.4

0.05

Rajasthan

Banasthali

Radio Banasthali (Banasthali Vidyapheet

90.4

0.05

Rajasthan

Jaipur

Engineering College)

University) FM Radio 7 (India International Institute of Management, IIIM) 90.4

0.05

Tamil Nadu

Chennai [Madras]

Anna FM @ 90.4 (Anna University)

90.4

0.05

Tamil Nadu

Dindigul

Pasumai FM

90.4

0.05

Tamil Nadu

Erode (Perundurai) Kongu Engineering College (Kongu FM)

90.4

0.05

Tamil Nadu

Erode (Thiruchengode)

Mugil FM (Erode Sengunthar Engineering

90.4

0.05

Tamil Nadu

Tiruchirapalli

Holy Cross College

90.4

0.2

Tamil Nadu

Yercaud (Salem)

All India Radio (AIR FM Rainbow /

90.4

0.05

Uttar Pradesh Lucknow

90.8

0.05

Maharashtra

Pune

Vidyavani (University of Pune)

90.8

0.05

Tamil Nadu

Chennai [Madras]

Loyola FM (Loyola College, Chennai)

91.1

Andhra Pradesh

Hyderabad

Radio City

91.1

Andhra Pradesh

Visakhapatnam

Radio City

91.1

Delhi

Delhi

Radio City

91.1

Gujarat

Ahmedabad

Radio City

91.1

Gujarat

Surat

Radio City

91.1

Gujarat

Vadodara

Radio City

91.1

Karnataka

Benguluru [Bangalore]

Radio City

91.1

Maharashtra

Ahmednagar

Radio City

Maharashtra

Mumbai

College)

Akashvani)

91.1

20

City Montessori School (CMS)

[Bombay]

Radio City

91.1

Maharashtra

Nagpur

Radio City

91.1

Maharashtra

Solapur

Radio City

91.1

Rajasthan

Jaipur

Radio City

91.1

Tamil Nadu

Chennai [Madras]

Radio City

91.1

Tamil Nadu

Coimbatore

Radio City

91.1

Uttar Pradesh

Lucknow

Radio City

91.9

Goa

Panaji

Radio Indigo

91.9

Haryana

Hissar

Radio Mantra 91.9 FM

91.9

Haryana

Karnal

Radio Mantra 91.9 FM

FM provides high-fidelity sound over broadcast radio. FM broadcast band is from 87.5 to 108.0 MHz. VHF band extends from 30 MHz to 300 MHz. Thus FM belongs to VHF. The property of the High frequency signals is that they propagate only in line of sight i.e., upto 50 to 100 Km .And these signals never reflects or refracts. But in the ionosphere these signals reflects back to earth. Dxing = D(Distant)+ X(Unknown) DX communication is communication over great distances using the ionosphere to refract the transmitted radio beam. The beam returns to the Earth’s surface, and may then be reflected back into the ionosphere for a second bounce. Ionospheric refraction is generally only feasible for frequencies below about 50 MHz, and is highly dependent upon atmospheric conditions, the time of day, and the eleven-year sunspot cycle. It is also affected by solar storms and some other solar events, which can alter the Earth’s ionosphere by ejecting a shower of charged particles.The angle of refraction places a minimum on the distance at which the refracted beam will first return to Earth. This distance increases with frequency. According to Dxing theory, an FM/TV signal from 700 to 1500 miles can be received.

62

63 SFM - Hyderabad - 93.5 MHz

A good DXing Pre-amplifier can be used.

SFM - Jaipur - 93.5 MHz

You can use any type of antenna like telescopic antenna, It is better to use, dipole antenna or Yagi antenna. Length of the dipole depends on frequency. I am an Electronics Eng student, The circuits for dxing, booster, signal amp., were assembled by myself. All are available in the market.

SFM - Bhubaneshwar - 93.5 MHz SFM - Tirupati - 93.5 MHz SFM - Lucknow - 93.5 MHz

The antenna for reception is designed by myself.

SFM - Bhopal - 93.5 MHz

for eg. in yagi antenna, the dimensios as as follows:

SFM - Kozhikode - 93.5 MHz

The first director is 120 / F if F = 88 MHZ then 120 / 88 = 1,36 Meters.

SFM - Indore - 93.5 MHz

1 director 1 120 / frequency

SFM - Vijayawada - 93.5 MHz

A interval betwen 1 et 2 60 / frequency

SFM - Varanasi - 93.5 MHz

2 director 2 125 / frequency

SFM - Rajahmundry - 93.5 MHz

B interval betwen 2 et 3 45 / frequency

SFM - Trivandrum - 93.5 MHz

3 director 3 130 / frequency

SFM - Kanpur - 93.5 MHz

C interval betwen 3 et 4 30 / frequency 4 director 4 138 / frequency

FM Radio Stations in India

D interval betwen 4 et 5 30 / frequency 5 Dipôle 143 / frequency E interval betwen 5 et 6 48 / frequency 6 reflector 150 / frequency Suryan FM - Chennai - 93.5 MHz Suryan FM - Coimbatore - 93.5 MHz Suryan FM - Tirunelveli - 93.5 MHz Suryan FM - Madurai - 93.5 MHz

Frequency Transmitter State / (MHz) Power (kW)

Location

Station

90.4

0.05

Tamil Nadu

Erode

Kongu Arts and Science College

90.4

0.05

Delhi

New Delhi

DU 90.4 FM (Delhi University)

90.4

0.05

Delhi

New Delhi

Radio Jamia (Jamia Millia Islamia Uiversity)

90.4

0.02

Goa

Mapusa

Voice of Xavier’s (VOX, St Xavier’s Colege

Gujarat

Ahmedabad

Gujarat

Vallabh

of Arts, Science & Commerce) 90.4

Communications) 90.4

0.05

Vidyanagar

Suryan FM - Tuticorin - 93.5 MHz

Vallabh Vidyanagar Campus Radio (Sardar Patel University)

Suryan FM - Pondicherry - 93.5 MHz

90.4

0.05

Karnataka

Dharwad

Suryan FM - Trichy - 93.5 MHz

90.4

0.05

Kerala

Thiruvananthapuram

FM90.4 (Samudaya Banuli Kendra, University of Agricultural Sciences)

SFM - Vishakapatinam - 93.5 MHz SFM - Bangalore - 93.5 MHz

Micavaani (Mudra Institute of

[Trivandrum]

DC FM (D.C. Kizhakkemuri Foundation /

Baramati, Pune

Vasundhara Vahini (Vidya Pratishthan

DCSMAT Media School) 90.4

0.05

Maharashtra

Institute of Information Technology, VIIT)

68

65

Frequency Transmitter State / (MHz) Power (kW)

Location

95

Rajasthan

Jaipur

95

West Bengal Kolkata II [Calcutta]

All India Radio (AIR / Akashvani)

Gujarat

Rajkot

All India Radio (AIR / Akashvani / Vividh

Assam

Guwahati [Gauhati],

*95.8

10

Station

Frequency Transmitter State / (MHz) Power (kW)

Location

Radio Tadka 95 FM

91.9

Karnataka

Benguluru

91.9

Kerala

[Bangalore]

Bharati) 96

Kamrup District

96 96.7 96.9

10 0.05

Assam

Guwahati [Gauhati],

Gujarat

Ahmedabad

Delhi

New Delhi

Kamrup District

[Calicut]

All India Radio

Radio Indigo

Kozhikode

All India Radio

(AIR / Akashvani)

Station

Radio Mango 91.9 FM (Malayala Manorama)

91.9

Punjab

Jalandhar

Radio Mantra 91.9 FM

91.9

Tamil Nadu

Chennai [Madras]

Aahaa FM

(AIR / Akashvani)

91.9

Tamil Nadu

Coimbatore

Gyan Vani

All India Radio (AIR / Akashvani / Vividh

91.9

Uttar Pradesh

Agra

Radio Mantra 91.9 FM

Bharati)

91.9

Uttar Pradesh

Bareilly

Radio Mantra 91.9 FM

IIMC Radio (Indian Institute of Mass

91.9

Uttar Pradesh

Gorakhpur

Radio Mantra 91.9 FM

Communication, IIMC)

91.9

Uttar Pradesh

Varanasi [Benares]

Radio Mantra 91.9 FM

10

97

West Bengal Kolkata [Calcutta]

All India Radio (AIR Kolkata B /Akashvani)

91.9

West Bengal Kolkata [Calcutta]

ZFriends FM (Ananda Bazaar Patrika group)

98.3

Andhra Pradesh

Hyderabad Radio Mirchi

92.7

Andhra Pradesh

Hyderabad

Big 92.7 FM

98.3

Andhra Pradesh

Vijayawada Radio Mirchi

92.7

Andhra Pradesh

Tirupati

Big 92.7 FM

98.3

Bihar

Radio Mirchi

92.7

Andhra Pradesh

Vishakhapatnam

Big 92.7 FM

98.3

Chhattisgarh Raipur

Radio Mirchi

92.7

Andhra Pradesh

Vishakhapatnam

Big 92.7 FM

98.3

Delhi

Delhi

Radio Mirchi

92.7

Assam

Guwahati [Gauhati]

Big 92.7 FM

Patna

98.3

Goa

Panaji

Radio Mirchi

92.7

Chandigarh

Chandigarh

Big 92.7 FM

98.3

Gujarat

Ahmedabad

Radio Mirchi

92.7

Delhi

Delhi

Big 92.7 FM

98.3

Gujarat

Rajkot

Radio Mirchi

92.7

Goa

Panaji

Big 92.7 FM

98.3

Gujarat

Surat

Radio Mirchi

92.7

Gujarat

Rajkot

Big 92.7 FM

98.3

Gujarat

Vadodara [Baroda] Radio Mirchi

92.7

Gujarat

Surat

Big 92.7 FM

98.3

Karnataka

Benguluru

92.7

Gujarat

Vadodara [Baroda] Big 92.7 FM

[Bangalore]

Radio Mirchi

92.7

Haryana

Hissar

98.3

Karnataka

Mangalore

Radio Mirchi

92.7

Jammu & Kashmir Jammu

98.3

Kerala

Thiruvananthapuram

92.7

Jammu & Kashmir Srinagar

Big 92.7 FM

Radio Mirchi

92.7

Jharkhand

Jamshedpur

Big 92.7 FM Big 92.7 FM

[Trivandrum]

Big 92.7 FM Big 92.7 FM

98.3

Madhya Pradesh Bhopal

Radio Mirchi

92.7

Jharkhand

Ranchi

98.3

Madhya Pradesh Indore

Radio Mirchi

92.7

Karnataka

Benguluru

98.3

Madhya Pradesh Jabalpur

Radio Mirchi

[Bangalore]

Big 92.7 FM

98.3

Maharshtra

Kolhapur

Radio Mirchi

92.7

Karnataka

Mangalore

Big 92.7 FM

98.3

Maharashtra

Mumbai [Bombay] Radio Mirchi

92.7

Karnataka

Mysore

Big 92.7 FM

98.3

Maharashtra

Nagpur

92.7

Kerala

Thiruvananthapuram

Radio Mirchi

[Trivandrum]

Big 92.7 FM

98.3

Maharshtra

Nasik

Radio Mirchi

98.3

Maharashtra

Pune [Poona]

Radio Mirchi

92.7

Madhya Pradesh

Bhopal

Big 92.7 FM

98.3

Punjab

Jalandhar

Radio Mirchi

92.7

Madhya Pradesh

Gwalior

Big 92.7 FM

98.3

Rajasthan

Jaipur

Radio Mirchi

92.7

Madhya Pradesh

Indore

Big 92.7 FM

98.3

Rajasthan

Rajkot

Radio Mirchi

92.7

Maharashtra

98.3

Tamil Nadu

Chennai [Madras]

Radio Mirchi

Mumbai [Bombay]

Big 92.7 FM

66

67

Frequency Transmitter State / (MHz) Power (kW)

Location

92.7

Maharashtra

92.7

Orissa

92.7

Orissa

92.7

Pondicherry

92.7

Punjab

92.7

Punjab

Jalandhar

92.7

Punjab

92.7

Station

Frequency Transmitter State / (MHz) Power (kW)

Location

Station

Solapur [Sholapur] Big 92.7 FM

93.5

Tamil Nadu

Madurai

Suryan FM

Bhubaneswar

Big 92.7 FM

93.5

Tamil Nadu

Tiruchirapalli

Kal Radio Ltd (S FM)

Rourkela

Big 92.7 FM

93.5

Tamil Nadu

Tirunelveli

Suryan FM

Pondicherry

Big 92.7 FM

93.5

Tamil Nadu

Tuticorin

Amritsar

Big 92.7 FM

[Thoothukudi]

Suryan FM

Big 92.7 FM

93.5

Uttar Pradesh

Kanpur

South Asia FM (S FM)

Patiala

Big 92.7 FM

93.5

Uttar Pradesh

Lucknow

South Asia FM (S FM)

Rajasthan

Ajmer

Big 92.7 FM

93.5

Uttar Pradesh

Varanasi [Benares] South Asia FM (S FM)

92.7

Rajasthan

Bikaner

Big 92.7 FM

93.5

92.7

Rajasthan

Jodhpur

Big 92.7 FM

93.9

92.7

Rajasthan

Udaipur

Big 92.7 FM

92.7

Tamil Nadu

Chennai [Madras]

Big 92.7 FM

West Bengal Kolkata [Calcutta] Red FM 10

Gujarat

Vadodara [Baroda] All India Radio (AIR / Akashvani /

Chandigarh

Chandigarh

Vividh Bharati) 94.3

MY FM (Bhaskar Group)

92.7

Uttar Pradesh

Agra

Big 92.7 FM

94.3

Chhattisgarh Bilaspur

92.7

Uttar Pradesh

Aligarh

Big 92.7 FM

94.3

Chhattisgarh Raipur

MY FM (Bhaskar Group)

92.7

Uttar Pradesh

Allahabad

94.3

Delhi

Delhi

Radio One

92.7

Uttar Pradesh

Bareilly

94.3

Gujurat

Ahmedabad

MY FM (Bhaskar Group)

92.7

Uttar Pradesh

Jhansi

94.3

Gujurat

Surat

MY FM (Bhaskar Group)

92.7

Uttar Pradesh

Kanpur

94.3

Karnataka

Benguluru

92.7

West Bengal Asansol

[Bangalore]

Radio One

92.7

West Bengal Kolkata [Calcutta] Big 92.7 FM

94.3

Kannur

Thrissur

Club FM 94.3 (Mathrubhumi)

92.7

West Bengal Siliguri

High 92.7 FM (Sun Infomedia Pvt. Ltd.)

94.3

Kerala

Thrissur

93.5

Andhra Pradesh

Hyderabad

South Asia FM (S FM)

94.3

Madhya Pradesh Bhopal

MY FM (Bhaskar Group)

93.5

Andhra Pradesh

Rajahmundry

Sun Networks (S FM)

94.3

Madhya Pradesh Gwalior

MY FM (Bhaskar Group)

93.5

Andhra Pradesh

Tirupati

Kal Radio Ltd. (S FM)

94.3

Madhya Pradesh Indore

MY FM (Bhaskar Group)

93.5

Andhra Pradesh

Vijayawada

Kal Radio Ltd. (S FM)

94.3

Madhya Pradesh Jabalpur

MY FM (Bhaskar Group)

93.5

Andhra Pradesh

Visakhapatnam

South Asia FM (S FM)

94.3

Maharashtra

Kolhapur

Radio Tomato

93.5

Delhi

Delhi

Red FM

94.3

Maharashtra

Mumbai [Bombay] Radio One (formerly Go 92.5)

93.5

Karnataka

Benguluru [Bangalore]

Big 92.7 FM Big 92.7 FM Big 92.7 FM

20

MY FM (Bhaskar Group)

Club FM 94.3 (Mathrubhumi)

94.3

Maharashtra

Nagpur

MY FM (Bhaskar Group)

South Asia FM (S FM)

94.3

Punjab

Amritsar

MY FM (Bhaskar Group)

93.5

Karnataka

Mangalore

Kal Radio Ltd. (S FM)

94.3

Punjab

Jallandhar

MY FM (Bhaskar Group)

93.5

Kerala

Kozhikode [Calicut]

South Asia FM (S FM)

94.3

Rajasthan

Ajmer

MY FM (Bhaskar Group)

93.5

Kerala

Thrissur

Kal Radio Ltd. (S FM)

94.3

Rajasthan

Jaipur

MY FM (Bhaskar Group)

93.5

Madhya Pradesh Bhopal

South Asia FM (S FM)

94.3

Rajasthan

Jodhpur

MY FM (Bhaskar Group)

93.5

Madhya Pradesh Indore

Sun TV Network (S FM)

94.3

Rajasthan

Kota

MY FM (Bhaskar Group)

93.5

Maharashtra

Mumbai [Bombay] Red FM

94.3

Rajasthan

Udaipur

MY FM (Bhaskar Group)

93.5

Orissa

Bhubaneshwar

South Asia FM (S FM)

94.3

Tamil Nadu

Chennai [Madras]

Radio One

93.5

Pondicherry

Pondicherry

South Asia FM (Kal FM / S FM)

94.3

West Bengal Siliguri

93.5

Rajasthan

Jaipur

South Asia FM (S FM)

*94.6

Maharashtra

Mumbai [Bombay] Win 94.6

Radio Misty FM (Sun Infomedia Pvt. Ltd.)

93.5

20

Tamil Nadu

Chennai [Madras]

Suryan FM

95

Delhi

Delhi

HIT 95 FM

93.5

10

Tamil Nadu

Coimbatore

Suryan FM

95

Kerala

Thrissur

Best 95 FM

72

69

Frequency Transmitter State / (MHz) Power (kW)

Location

101.9

Thiruvanathapuram

10

Kerala

[Trivandrum]

Station

All India Radio (AIR / Akashvani / Vividh

Bharati) 101.9

6

Mizoram

Lungleh

All India Radio (AIR / Akashvani)

101.9 101.9

3

Orissa

Bolangir

All India Radio (AIR / Akashvani)

6

Uttar Pradesh

Faizabad

All India Radio (AIR / Akashvani)

102

10

Andhra Pradesh

Visakhapatnam

All India Radio (AIR FM Rainbow Vizak /

102

6

Madhya Pradesh Shahdol

102.1

3

Jharkhand

Hazaribagh

All India Radio (AIR / Akashvani)

102.1

6

Karnataka

Raichur

All India Radio (AIR / Akashvani)

102.1

6

Rajasthan

Jodhpur

All India Radio (AIR / Akashvani / Vividh

102.1

10

Tamil Nadu

Tiruchirapalli

Akashvani)

All India Radio (AIR FM Rainbow / Akashvani)

102.2

10 1

Uttaranachal Mussoorie Andhra Pradesh

[Musoorie]

All India Radio (AIR / Akashvani)

Vijayawada

All India Radio (AIR / FM Rainbow Krishnaveni)

102.2

6

Chhattisgarh Chindwara

All India Radio (AIR / Akashvani)

102.2

6

Gujarat

Godhra

All India Radio (AIR / Akashvani)

102.2

10

Jammu & Kashmir Kathua

All India Radio (AIR / Akashvani)

102.2

6

Karnataka

102.2

6

West Bengal Murshidabad

Hassan

All India Radio (AIR / Akashvani) All India Radio (AIR / Akashvani)

102.3

6

Bihar

Purnea

All India Radio (AIR / Akashvani)

102.3

3

Daman & Diu Daman

All India Radio (AIR / Akashvani)

102.3

6

Haryana

Hissar

All India Radio (AIR / Akashvani)

102.3

3

Karnataka

Karwar,Uttara Kannada District All India Radio (AIR / Akashvani)

102.3

6

Kerala

102.3

6

Madhya Pradesh Guna

102.3

10

Tamil Nadu

102.3

10

West Bengal Kurseong

All India Radio (AIR FM Rainbow /

Andhra Pradesh Gujarat

Kurnool Rajkot

Akashvani) All India Radio (AIR / Akashvani) All India Radio (AIR / Akashvani / Vividh Bharati)

Maharashtra

Akola

All India Radio (AIR / Akashvani)

102.4 102.4

6 10

102.4

6

102.4 102.5

Kochi A [Cochin]

All India Radio (AIR / Akashvani) All India Radio (AIR / Akashvani)

Chennai II [Madras] All India Radio (AIR FM Gold / Akashvani)

West Bengal Kolkata [Calcutta] All India Radio (AIR Kolkata I / Akashvani) 6

Bihar

Patna

Location

Station

98.3

Tamil Nadu

Madurai

Radio Mirchi

98.3

Uttar Pradesh

Kanpur

Radio Mirchi

98.3

Uttar Pradesh

Lucknow

Radio Mirchi

98.3

Uttar Pradesh

Varanasi

Radio Mirchi

98.3

West Bengal Kolkata [Calcutta] Radio Mirchi

100.1

6

Andhra Pradesh

Kothagudem

100.1

3

Karnataka

Benguluru [Bangalore]

All India Radio (AIR / Akashvani)

Bharati)

102.1

Frequency Transmitter State / (MHz) Power (kW)

All India Radio (AIR / Akashvani / Vividh Bharati)

All India Radio (AIR / Akashvani) All India Radio (AIR Classical Music Channel / Akashvani / Amrutha Varshini)

100.1

6

Maharashtra

Ahmednagar

All India Radio (AIR / Akashvani)

100.1

1

Uttar Pradesh Gorakhpur

100.2

6

Assam

100.2

10

Uttar Pradesh Lucknow

All India Radio (AIR / Akashvani)

100.2

6

Madhya Pradesh Shivpuri

All India Radio (AIR / Akashvani)

All India Radio (AIR / Akashvani / Vividh Bharati) Haflong,North Cachar

Hills District

Patiala

All India Radio (AIR / Akashvani)

100.2

6

Punjab

100.2

10-May

West Bengal Kolkata II [Calcutta]

All India Radio (AIR / Akashvani)

100.3

10

Karnataka

100.3

6

Puducherri [Pondicherry] Karaikal

All India Radio (AIR / Akashvani)

100.3

6

Rajasthan

All India Radio (AIR / Akashvani / Vividh

100.3

10

Uttar Pradesh Allahabad

100.3

6

West Bengal Asansol

All India Radio (AIR FM Gold / Akashvani)

Mangalore,Dakshina Kannada District

Jaipur B

All India Radio (AIR / Akashvani)

Bharati) All India Radio (AIR / Akashvani / Vividh Bharati) All India Radio (AIR / Akashvani)

100.4

Karnataka

Benguluru

100.4

Madhya Pradesh Mandla

All India Radio (AIR / Akashvani)

[Bangalore]

AIR Music Service

100.4

6

Uttar Pradesh Bareilly

All India Radio (AIR / Akashvani)

100.5

3

Jammu & Kashmir Jammu

All India Radio (AIR / Akashvani)

100.5

10

Karnataka

Hospet

All India Radio (AIR / Akashvani)

100.5

6

Maharashtra

Dhule

All India Radio (AIR / Akashvani)

100.5

10

Tamil Nadu

Kodaikanal

All India Radio (AIR FM Rainbow /

100.6

10

Karnataka

Mysore

100.6

6

Maharashtra

Nagpur

Akashvani) All India Radio (AIR / Akashvani) All India Radio (AIR / Akashvani / Vividh Bharati)

70

71

Frequency Transmitter State / (MHz) Power (kW)

Location

Station

Frequency Transmitter State / (MHz) Power (kW)

Location

100.6

6

Orissa

Berhampur

All India Radio (AIR / Akashvani)

101.3

Benguluru

100.6

6

Uttar Pradesh Varanasi [Benares] All India Radio (AIR / Akashvani / Vividh

10

Karnataka

[Bangalore]

Bharati) 100.7

10

Uttar Pradesh Lucknow

100.7

6

Chhatisgarh

100.7

6

Jammu & Kashmir

100.7 100.7

10 6

Akashvani)

All India Radio (AIR FM Rainbow /

101.3

6

Madhya Pradesh Balaghat

All India Radio (AIR / Akashvani)

101.3

6

Maharashtra

Osmanabad

All India Radio (AIR / Akashvani)

All India Radio (AIR / Akashvani)

101.3

6

Orissa

Cuttack

All India Radio (AIR FM Rainbow /

Akashvani)

101.3

10

Puducherri

[Bombay]

All India Radio (AIR FM Gold / Akashvani)

101.3

6

Rajasthan

Banswara

All India Radio (AIR / Akashvani)

Mizoram

Aizawl

All India Radio (AIR / Akashvani)

101.3

6

Uttar Pradesh

Aligarh

All India Radio (AIR FM Rainbow /

All India Radio (AIR / Akashvani) 101.4

6

Haryana

Kurukshetra [Kurushetra]

All India Radio (AIR / Akashvani)

101.4

6

Kerala

Devikulam

All India Radio (AIR / Akashvani)

Maharashtra

Poonch

All India Radio (AIR /

6

Rajasthan

Churu

10

Assam

Guwahati [Gauhati], Kamrup District

[Pondicherry] Pondicherry

Jamshedpur,

101.4

6

Maharashtra

Nasik

All India Radio (AIR / Akashvani)

East Singhbhum District All India Radio (AIR / Akashvani / Vividh

101.4

20

Tamil Nadu

Chennai I [Madras]

All India Radio (AIR FM Rainbow /

101.4

10-Mar

West Bengal Siliguri

Akashvani / Vividh Bharati)

101.5

6

Andhra Pradesh

Markapur

All India Radio (AIR / Akashvani / Vividh

101.5

6

Kerala

Kannur [Cannanore] All India Radio (AIR / Akashvani)

Bharati) 100.9

6

Nagaland

100.9

10

Andaman & Nicobar Islands

100.9

1

100.9

Mukokchung

Himachal Pradesh Simla [Shimla] Tamil Nadu

Yercaud (Salem)

101

6

Jammu & Kashmir

101

6

Maharashtra

Akashvani)

All India Radio (AIR / Akashvani) Port Blair

All India Radio (AIR /

Pune [Poona]

101.5

6

Rajasthan

Sawai Madhopur

All India Radio (AIR / Akashvani)

101.6

10

Chhatisgarh

Raipur

Bhaderwah All India Radio (AIR /

101.6

6

Madhya Pradesh Indore

101.6

10

Tripura

Agartala

All India Radio (AIR / Akashvani / Vividh

101.7

6

Andhra Pradesh

Anantapur

All India Radio (AIR / Akashvani)

101.7

6

Jharkhand

Chaibasa [Chaibassa],

101.7

1

Maharashtra

Aurangabad

All India Radio (AIR / Akashvani)

101.7

1

Rajasthan

Udaipur

All India Radio (AIR / Akashvani / Vividh

All India Radio (AIR / Akashvani / Vividh

101

5

Orissa

Deogarh

101

10

Tamil Nadu

Nagercoil,Kanniyakumari

All India Radio (AIR / Akashvani / Vividh Bharati) All India Radio (AIR / Akashvani)

West Bengal Kolkata [Calcutta] All India Radio (AIR / Akashvani / Vividh 6

Gujarat

All India Radio (AIR / Akashvani) All India Radio (AIR / Akashvani) All India Radio (AIR / Akashvani / Vividh Bharati) Bharati)

West Singhbhum District All India Radio (AIR / Akashvani)

Bharati) 101.1

All India Radio (AIR / Akashvani)

Bharati)

Bharati)

District

All India Radio (AIR / Akashvani / Vividh Bharati)

Akashvani)

101

All India Radio (AIR / Akashvani)

Akashvani)

All India Radio (AIR / Akashvani / Vividh Bharati)

Jharkhand

Akashvani)

Mumbai II

100.7

6

All India Radio (AIR FM Rainbow /

Akashvani) Raigarh

100.8

100.8

Station

Bharati)

Surat

All India Radio (AIR / Akashvani / Vividh

101.8

6

Himachal Pradesh Hamirpur

All India Radio (AIR / Akashvani)

101.8

6

Karnataka

Bijapur

All India Radio (AIR / Akashvani)

Nanded Jowai Bathinda

Bharati) All India Radio (AIR / Akashvani) All India Radio (AIR / Akashvani) All India Radio (AIR / Akashvani)

101.8

10

Rajasthan

Jaisalmer

All India Radio (AIR / Akashvani)

101.9

10

Andhra Pradesh

Hyderabad

All India Radio (AIR / Akashvani / Twin

101.9

10

Jammu & Kashmir Rajouri

101.1 101.1 101.1

6 6 6

Maharashtra Meghalaya Punjab

101.2

6

Madhya Pradesh Khandwa,East Nimar District

All India Radio (AIR / Akashvani)

Cities FM Rainbow) All India Radio (AIR / Akashvani)

76

73

Frequency Transmitter State / (MHz) Power (kW)

Location

Station

Frequency Transmitter State / (MHz) Power (kW)

106.4

Haryana

Karnal

Radio Dhamaal 24 (BAG Films & Media Ltd)

102.5

6

Himachal Pradesh Kullu

All India Radio (AIR / Akashvani)

106.4

Jharkhand

Ranchi

Radio Dhamaal 24 (BAG Films & Media Ltd)

102.5

10

Tamil Nadu

Dharmapuri

All India Radio (AIR / Akashvani)

106.4

Madhya Pradesh Jabalpur

Radio Dhamaal 24 (BAG Films

102.6

10

Delhi

Delhi I

All India Radio (AIR FM Rainbow /

106.4

Maharashtra

Dhule

Radio Dhamaal 24 (BAG Films & Media Ltd)

102.6

10

Jammu & Kashmir Srinagar

All India Radio (AIR / Akashvani / Vividh

106.4

Pondicherry

Pondicherry

Hello FM (Malar Publications)

106.4

Punjab

Patiala

Radio Dhamaal 24 (BAG Films & Media Ltd)

102.6

6

Karnataka

All India Radio (AIR / Akashvani)

106.4

Tamil Nadu

Chennai

Hello FM (Malar Publications)

102.6

5

Madhya Pradesh Sagar

106.4

Tamil Nadu

Coimbatore

Hello FM (Malar Publications)

102.6

6

Orissa

Rourkela

All India Radio (AIR / Akashvani)

106.4

Tamil Nadu

Madurai

Hello FM (Malar Publications)

102.7

6

Assam

Nagaon

All India Radio (AIR / Akashvani)

106.4

Tamil Nadu

Tirunelveli

Hello FM (Malar Publications)

102.7

10

Kerala

Manjery

All India Radio (AIR / Akashvani)

106.4

Tamil Nadu

Tuticorin

102.7

6

Maharashtra

Kolhapur

All India Radio (AIR / Akashvani)

Hello FM (Malar Publications)

102.7

6

Maharashtra

Yeotmal [Yavatmal] All India Radio (AIR / Akashvani)

102.7

10

Punjab

Jalandhar

All India Radio (AIR FM Rainbow /

102.7

6

Rajasthan

Obra

All India Radio (AIR / Akashvani)

102.8

6

Andhra Pradesh

Hyderabad

All India Radio (AIR / Akashvani / Vividh

& Media Ltd)

[Thoothukudi] 106.6

10

Madhya Pradesh Indore

Gyan Vani

107

10

West Bengal Kolkata I [Calcutta]

All India Radio (AIR FM Rainbow / Akashvani)

107.1

10

Maharashtra

Mumbai I [Bombay]

All India Radio (AIR FM Rainbow / Akashvani)

107.2

10

Himachal Pradesh Kasauli

107.2

10

Karnataka

All India Radio (AIR National Channel / Akashvani)

[Bangalore]

Gyan Vani

107.4

10

Uttar Pradesh

Allahabad

Gyan Vani

107.5

10-Mar

Andhra Pradesh

Tirupati II

All India Radio (AIR / Akashvani)

107.5

10

Kerala

Kochi B [Cochin]

All India Radio (AIR / Akashvani / FM Rainbow)

107.8

10

Assam

Guwahati [Gauhati] Gyan Vani

107.8

10

Gujarat

Rajkot

107.8

0.05

Karnataka

Bengalaru [Bangalore]

Gyan Vani Radio Active (RA, Jain Group of Institutions)

107.8

10

Maharashtra

Nagpur

Gyan Vani

107.8

0.05

Tamil Nadu

Chennai [Madras]

MOP FM (MOP Vaishnav College)

107.8

West Bengal Kolkata [Calcutta] Power 107.8 FM

Station

Akashvani) Bharati) Chitradurga

All India Radio (AIR / Akashvani)

Akashvani)

Bharati) 102.8 102.9

Chhattisgarh Saraipalli 10

Karnataka

Bangalore II

All India Radio (AIR / Akashvani) All India Radio (AIR / Akashvani / Vividh Bharati)

102.9

6

Maharashtra

Beed

All India Radio (AIR / Akashvani / Vividh Bharati) All India Radio (AIR / Akashvani)

102.9

5

Orissa

Baripada

All India Radio (AIR / Akashvani)

102.9

6

Rajasthan

Chittorgarh

All India Radio (AIR / Akashvani)

103

6

Jharkhand

Daltonganj, Palamau District

All India Radio (AIR / Akashvani)

103

10

Karnataka

Dharwad

All India Radio (AIR / Akashvani)

103

6

Maharashtra

Chandrapur [Chanderpur]

All India Radio (AIR / Akashvani)

103

10

Nagaland

Kohima

All India Radio (AIR / Akashvani)

103

10

Tamil Nadu

Coimbatore

102.9

Bengalaru

Location

10

Madhya Pradesh Jabalpur

All India Radio (AIR FM Rainbow / Akashvani)

103

6

103

Uttar Pradesh Jhansi

All India Radio (AIR / Akashvani)

West Bengal Kolkata [Calcutta] All India Radio (AIR Kolkata A / Akashvani)

103.1

10

Arunachal Pradesh Itanagar

All India Radio (AIR / Akashvani)

103.1

6

Chandigarh

All India Radio (AIR / Akashvani / Vividh

Chandigarh

Bharati)

74

75

Frequency Transmitter State / (MHz) Power (kW)

Location

103.1

Madikeri,Kodagu

6

Karnataka

District 103.1

6

Madhya Pradesh Betul

Station

Frequency Transmitter State / (MHz) Power (kW)

Location

Station

Cokelate 104 FM

104

Orissa

Bhubaneswar

All India Radio (AIR / Akashvani)

104

Orissa

Rourkela

All India Radio (AIR / Akashvani)

104

10

Uttar Pradesh Kanpur

Cokelate 104 FM Gyan Vani

103.1

6

Maharashtra

Satara

All India Radio (AIR / Akashvani)

104

West Bengal Kolkata

Fever 104 FM (HT Media Ltd / Virgin)

103.1

6

Rajasthan

Alwar

All India Radio (AIR / Akashvani)

104

West Bengal Kolkata II [Calcutta]

All India Radio (AIR / Akashvani)

103.1

3

West Bengal Shanti Nikethan

All India Radio (AIR / Akashvani)

104.2

Madhya Pradesh Bhopal

Gyan Vani

103.2

6

Andhra Pradesh

Nizamabad

All India Radio (AIR / Akashvani)

104.2

10

Tamil Nadu

Gyan Vani

103.2

10

Andhra Pradesh

Tirupati I

All India Radio (AIR / Akashvani)

104.5

10

Jammu & Kashmir Jammu B

103.2

6

Chhattisgarh Bilaspur

Chennai [Madras]

All India Radio (AIR / Akashvani)

All India Radio (AIR / Akashvani / Vividh Bharati)

103.2

6

Rajastham

Jhalawar

All India Radio (AIR / Akashvani)

104.8

103.2

6

Tripura

Kailashahar

All India Radio (AIR / Akashvani)

104.8

103.3

6

Assam

Dhubri

All India Radio (AIR / Akashvani)

103.3

6

Jharkhand

Ranchi

All India Radio (AIR / Akashvani / Vividh Bharati)

104.8

West Bengal Kolkata [Calcutta]

Radio Today (Radio Meow FM)

103.3

1

Tamil Nadu

Madurai

All India Radio (AIR / Akashvani)

105

Madhya Pradesh Bhopal

Gyan Vani

103.4

10

Assam

Jorhat

All India Radio (AIR / Akashvani)

105.2

10

Karnataka

Mysore

Gyan Vani

103.4

6

Bihar

Sasaram

All India Radio (AIR / Akashvani)

105.4

6

Goa

Panaji

103.4

10

Himachal Pradesh Dharamsala

All India Radio (AIR / Akashvani)

103.4

3

Orissa

Puri

All India Radio (AIR / Akashvani)

105.4

10

Gujarat

Ahmedabad

All India Radio (AIR FM Rainbow / Akashvani) Gyan Vani

103.5

10

Andhra Pradesh

Warangal

105.4

10

Meghalaya

Shillong

Gyan Vani

103.5

1

Haryana

Delhi

Delhi

Radio Today (Radio Meow FM)

Maharashtra

Aurangabad

Gyan Vani

104.8

Maharashtra

Mumbai

Radio Today (Radio Meow FM)

104.8

Tamil Nadu

Chennai

Muthoot Group

10

[Waranagal]

All India Radio (AIR / Akashvani)

105.4

10

West Bengal Kolkata [Calcutta] Gyan Vani

Rohtak

All India Radio (AIR / Akashvani / Vividh

105.6

10

Andhra Pradesh

Hyderabad

Bharati)

105.6

10

Andhra Pradesh

Visakhapatnam

Visakha FM

Patna

Gyan Vani

Gyan Vani

103.5

6

Madhya Pradesh Bhopal

All India Radio (AIR / Akashvani / Vividh

105.6

10

Bihar

Bharati)

105.6

10

Chhattisgarh Raipur

Gyan Vani

103.5

6

Manipur

Churachandpur

All India Radio (AIR / Akashvani)

105.6

10

Delhi

Delhi

Gyan Vani

103.5

10

Manipur

Imphal

All India Radio (AIR / Akashvani)

105.6

10

Goa

Patna

Gyan Vani

103.5

6

Rajasthan

Mount Abu

All India Radio (AIR / Akashvani)

105.6

10

Karnataka

Benguluru

103.6

10

Kerala

Kozhikode [Calicut] All India Radio (AIR / Akashvani / Vividh Bharati)

105.6

10

Madhya Pradesh Bhopal

Gyan Vani Gyan Vani

[Bangalore]

Gyan Vani

103.6

10

Meghalaya

Shillong

All India Radio (AIR / FM Rainbow)

105.6

10

Madhya Pradesh Jabalpur

103.7

1

Karnataka

Gulbarga

All India Radio (AIR / Akashvani / Vividh

105.6

10

Maharashtra

Mumbai [Bombay] Gyan Vani

Bharati)

105.6

10

Rajasthan

Jaipur

103.7

6

Rajasthan

Nagaur

All India Radio (AIR / Akashvani)

105.6

10

Uttar Pradesh Lucknow

103.7

6

Tripura

Belonia

All India Radio (AIR / Akashvani)

105.6

10

Uttar Pradesh Varanasi [Benares] Gyan Vani

104

Delhi

Delhi

Fever 104 FM (HT Media Ltd / Virgin)

106.2

104

Haryana

Hissar

Radio Tarang

106.4

10

Andhra Pradesh

Visakhapatnam

Gyan Vani

104

Karnataka

Benguluru

Bihar

Muzaffarpur

Radio Dhamaal 24 (BAG Films & Media ltd)

Delhi

Delhi II

All India Radio (AIR FM Gold / Akashvani)

104

Maharashtra

Haryana

Hissar

Radio Dhamaal 24 (BAG Films & Media Ltd)

Fever 104 FM (HT Media Ltd / Virgin)

106.4 106.4

Gyan Vani

West Bengal Kolkata [Calcutta] Amar 106.2

106.4

Mumbai [Bombay] Fever 104 FM (HT Media Ltd / Virgin)

[Bangalore]

Gyan Vani

5