Heath 6M SSB Transmitter - Nostalgic Kits Central

1 Heath 6M. SSB Transmitter Kent Mi tche ll W3 WTO. Almost every metropolitan area of the ginning right at the m ike in put, let's follow United States h as experienced a boom in 6 the audio through the rig un til it emerges from meter activity during recent years .. d ue in the antenna coax jack as a single sideband rf no small respect to H eath's introduction of signal. T he heart of the rig is the balan ced their now fa mous 5 watt p ower house, the modulator shown in F ig. 2. A sp eech amplifier "Stxer.' Then too, and especially during b and not only boosts the mike input , but attenuates openings, quite a few of the boys may be the audio frequencies below 300 cps and above heard modulating a H eath 120 watt Seneca.

2 " 3000 cps, which experience has shown to b e Ind eed , O Uf most popular VH F b and might the only really necessary range for good voice sound altogether different without H eathkits. intelligibility. The audio is now split into two Now how ever, 6 meters is going to sound dif- eq ual, but 90 degree out of phase signals by feren t with H eathkits .. namely the HX-30. an aud io phase shift network. Amplified by T his new SSB Transmitter is going to become V3A and V3B, these voltages are applied to as popular as sliced bread !

3 The grids of b alan ced modulators V4 and V,5. A complete, self-contained unit (no t a An rf carrier is generated at mc by a "transverter"}, the H X 30 offers a fr equency crystal controlled oscillator V2B and also ap- coverage of 50 ,0 t o megacycles in four, plied to the grids of the balan ced modulators 1 megacycle steps, an ultrastab le fi ne tuning after it too has been split into two 90 degree VFO, and excellent on-the-air audio character- out of phase signals. So now, at the grids of istics with unw anted sideband suppression on V4 and V5 we h ave two separate carriers be- the order of 40 db.)

4 Carrier suppression is 50 ing combined with modulation . H ere is where db below maximum rf outp ut. we eliminate the carrier and produce the de- Provid ing 10 watts peak envelope p ow er sired single sideband signal. Both b alan ced output SSB, 10 walls of CW, and walls modulators, consisting of two triodes each, with AM , the rig m ay be used as an exciter for V4A, V4B and V5A, V5B, each have their a linear amplifier (such as H eath's HA-20, to grids connected in parallel for rf, and in push- be featured in a later article ) , or run "bare- pull for audio through.

5 The plates of each foot" w ith excellent results. balanced modulator are connected in push-pull T he single sideband signal is generated in through a commo n tank circuit and are 180. this transmiller by the phasing method. Be- degrees ou t of phase wi th each other. The V4. BALANCED. ~:lA. AUDIO~ ODULAT OR. u MODULATOR. T. SPEECf PHASE. SHIFT. CARRIER. OSCILLATQ! RF PHASE. SHI FT. BALANCED. M ODULATOR. TANK. 1 1. 5 me V'B. l vox aJRE"LAy l M ODULATOR I V5. BALANCED. ~ I MOCULATOR. II~ MC 42,4 SMC SO-S4MC. 1/2 V9.

6 V6A V7 I V6 FINAL. ; 1st MIXER 2nd MIXER DRIVER R F OUT. Me 1/2 V9. 8-9MC SO-S4 MC. HETERODYNE FINAL. OSCILLATOR tyFO ,~ CRYS T A L. OSCI L LATOR. FIGURE I. HX-30 BLOCK DIAGRAM. 112 73 MAGAZINE. TI S A RC. S X m rr, 2. 1 3 me H RA XD XEW. o r ig inal sealed cartons $9 .95. HEWLETT PACKARD. 6 146 Tu~. ne w 400 D YTYM's Tested and Gua ra nt eed $ ea, 2 1$ R G l 1A fU Coax Cable (72 ohm ). New .. $135 100 ft roll w 1'1. 259 ea end $ B erkeley ~t odel 5500C U niversal 100 ke cou nter & t imer L a b tes ted -perfec t $ Read N Save B C-46 J A Transmitter and A M ),[ od ulators Pl 258 double female conn ector.]

7 $.70 co nverts to 6 mtrs. uses 8 15 fin al 2 ea DB Mete rs 31h" rd-l0 to + 6db I mw @ 600 ohms $275 6 L 6 Modula tors -ne w w / t ubes $1 0. Spe rf Vacuum Switc hes for , etc. NEW $ Velv et Verniers w I la rge knob NEW $ 600 Ohm 300 Watt No n- inductive Res istors . , .. $ Coax Relays S P J T 28vdc WE 255A Polar Relays for TTP .. $4. 50 Gen eral Commu ni cat ions J N I2 QRC o r Soc ke ts for use with above relay .. NEW $ T hom ps on P roduct s 10 566. Ne w $ Ohmite Z 28 rf Chokes 3 / Ohmite Z 144 rf Chokes.

8 4 / leac h Relay #1351 110 vac s pst . T -179 /A R T -26 T ra n sm itt er s 300-600 mc. 35w Pl 259 o r SO 239 coax conn ..3 / B rand n ew "" ftubes. for ham T V $ NEW SURPLUS TUBES GUARANTEED $12 .95. 2C39A $ 8005 .. $ 250TH $ 3CX lOOA5 $ 4 250A . $ 4X250f $25 .00 -MONEY BACK GUARANTEE ON. 6 161 $35. 00 588 1 .. $ 807 .. $ 829 B 58. 50 4-125A .. $ 6AN5 .. $ ANYTHING WE SELL- 4 65A .. $ ALL SHIPMENTS BRONX, N. Y . We buy & sell large quantities of Military and Com- mercial Test Equipment. AN/GRC. PRC. TRC and test SPACE ELECTRONICS CO.

9 Eq uipment TS and AN / UPM or URM. What have you 218 West Tremont Ave. , Bronx 53 , N. Y. for sal e or trade? TRemont 8~5222. product of all these phase relationships re- sults in the carrier b eing balan ced out and four LAFAYETTE RADIO ELECTRONICS. sideb ands containing th e audi o, with two in- ASSOCIATE STORE. phase sid eb ands combining and two out of 6306 Bea(h Blvd ., Bu ena Park, Calif. See t he new l a fa yette and Ha llitrafte rs Tra ns: eivers! phase sidebands canceling .. leaving only Plus Hommo rlun d, Hy Coi n.)

10 C esce an d o t he rs a single sideband signa l. A m ore detailed ex- Phone (7 14 ) S22-1193 73 d e G eorg ~ D :lYb W 6SJ. plan ation of how this phasing occurs may b e found in severa l good texts available, such as the Single sideband Com munications Hand- book. Howa rd W . Sams and Co., Inc. ( from Rud ie Bookshop ) . T wo CARRIE R BAL- Ai\'C E cnntrols on the front panel of the HX- 30 are pots in the cathode circuits of the b al- anced modulators and enable their output volt- ages to be adjusted for equal amplitude.