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Title: Interesting HB Transmitter Post by: Carl WA1KPD on October 27, 2012, 09:51:10 PM Picked up a small HB xmtr at Nearfest. 6AS7 (osc), 25A6 (PA) and 25Z6 rectifier.
Straight AC no transformers, and it is modulated! Nice National plug in coil set Sounds like something out of an old Gernsback book or Mech Illustrated. Does it ring a bell with anyone? I can trace it but it is always easier if there is a schematic Thanks and 73 Carl /KPD Title: Re: Interesting HB Transmitter Post by: W7TFO on October 27, 2012, 10:20:49 PM Looks like a real sweetie :-*! I love HB over factory any day.
How does that jewel modulate, BTW? 73DG Title: Re: Interesting HB Transmitter Post by: W3GMS on October 28, 2012, 02:13:17 PM Picked up a small HB xmtr at Nearfest. 6AS7 (osc), 25A6 (PA) and 25Z6 rectifier. Straight AC no transformers, and it is modulated! Nice National plug in coil set Sounds like something out of an old Gernsback book or Mech Illustrated. Does it ring a bell with anyone? I can trace it but it is always easier if there is a schematic Thanks and 73 Carl /KPD Great find Carl. I am sure you will have fun with it. I often wonder why the ops build such rigs on such small chassis. Very busy under the chassis! Joe, W3GMS Title: Re: Interesting HB Transmitter Post by: KM1H on October 28, 2012, 04:38:25 PM I take it you meant a 6AG7 oscillator.
Title: Re: Interesting HB Transmitter Post by: Carl WA1KPD on October 28, 2012, 07:42:13 PM I take it you meant a 6AG7 oscillator. No, 6SA7 is what is in there Title: Re: Interesting HB Transmitter Post by: KM1H on November 03, 2012, 09:50:00 PM But you originally typed 6AS7 ;D
Title: Re: Interesting HB Transmitter Post by: Carl WA1KPD on November 04, 2012, 09:11:43 AM But you originally typed 6AS7 ;D Yep, I made a typo at first.Do you think the 6SA7 would be a good osc? Or maybe someone threw is in there to fill up a spot Title: Re: Interesting HB Transmitter Post by: KM1H on November 04, 2012, 09:21:54 AM Hallicrafters did it in the SX-28/32 by configuring as a triode. Strange but it works. AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
Ive used regular receive 6SK7 pentodes for VFO's but the 6AG7 is the best xtal oscillator going in an octal. Carl |