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THE AM BULLETIN BOARD => Technical Forum => Topic started by: mario_puzos on May 15, 2011, 03:20:28 PM



Title: circuit modulator with 4-250
Post by: mario_puzos on May 15, 2011, 03:20:28 PM
hi i need a modulator circuit with two valves or 6156 4-250 ???


Title: Re: circuit modulator with 4-250
Post by: WD5JKO on May 15, 2011, 06:08:59 PM
hi i need a modulator circuit with two valves or 6156 4-250 ???

Mario,

  I am not sure what you mean. Do you mean modulate a 4-250 by a 6156? If so, this could mean the 6156 would be a screen modulator, or clamp tube modulator?

   Looking around I found a neat two tube circuit with a 4-400 modulated by a bias shift modulator using a single 304TL:

http://www.813am.qsl.br/artigos/moduladores/hileman/the_bias_shift_modulator_cq_apr_54.pdf

Jim
WD5JKO


Title: Re: circuit modulator with 4-250
Post by: mario_puzos on May 15, 2011, 06:58:55 PM
hi jim I need a circuit that uses a modulator valve is to modulate 4-250 plated at a couple of 4-400



Title: Re: circuit modulator with 4-250
Post by: WD5JKO on May 15, 2011, 08:43:19 PM
hi jim I need a circuit that uses a modulator valve is to modulate 4-250 plated at a couple of 4-400

Mario, Look at the attached schematic. Maybe this is closer to what you are looking for?

Schematic from following source:
http://www.g8wrb.org/data/Eimac/Care-and-Feeding-of-Power-Tetrodes.pdf

Jim
WD5JKO



Title: Re: circuit modulator with 4-250
Post by: mario_puzos on May 15, 2011, 08:58:03 PM
thanks jim .. it will analyze a hug


Title: Re: circuit modulator with 4-250
Post by: flintstone mop on May 16, 2011, 03:46:36 PM
hmmmm
I'm getting the picture of a pair of 4-250's modulating a pair of 4-400's...........
I don't know if the 250's will make enough audio
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