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Title: Gates Audio Driver Post by: flintstone mop on January 10, 2015, 11:06:29 AM Anyone know how much P to P audio is on the grids of the 833A's?
Solid state driver or the quad of 807's audio driver?? A fellow ham had a ooops while he was operating his BC1-H1 and the audio is slightly different now. Thanks Fred Title: Re: Gates Audio Driver Post by: W4RFM on January 10, 2015, 01:46:42 PM I should be able to find your answer.
The Gates BC 1G also used 833's, and had two 807's driving. My Bauer 707 has two 6SJ7's driving the 4-400's. So I am guessing not much. I have a tube info sheet from RCA on the 833 somewhere. 2 x 807's in AB2 can do 120 watts , or they could be class A in that circuit and do 12-15! Found it, RCA says about 11 watts. Bob Title: Re: Gates Audio Driver Post by: Opcom on January 10, 2015, 02:12:00 PM The schematic + tube manuals should give a reasonable clue.
Title: Re: Gates Audio Driver Post by: flintstone mop on January 10, 2015, 03:14:37 PM The schematic is available online but no reference to how many VOLTS P-P needed to drive the 833A's
Fred Title: Re: Gates Audio Driver Post by: W3GMS on January 10, 2015, 03:32:19 PM According the the data sheet Bob attached, it looks like its 400V PTP.
Joe, GMS Title: Re: Gates Audio Driver Post by: K3YA on January 10, 2015, 11:19:08 PM 25 watts will drive PP 833's modulator tubes in a KW transmitter. Much less is marginal and will have more distortion. More will be cleaner.
Title: Re: Gates Audio Driver Post by: flintstone mop on January 11, 2015, 09:36:50 AM Thanks Joe,
I failed to see the attachment and those numbers will give a very close idea what could be there to drive the tubes in an audio mode. When troubleshooting a circuit problem and using a 'scope; the reference will always have to be Peak to Peak audio volts on the grids. There is no way, without more inaccurate calculations, to determine what wattage is available, and how that translates to peak to peak volts. The O'Scope is the best piece of test equipment one could have in their shack. I thought there would be some response from radio engineers who may have had some experience with the actual TX. Fred Title: Re: Gates Audio Driver Post by: PD0RTT on January 11, 2015, 09:54:21 AM Normally triodes are fed by an kathode follower, voltage amplification take's place before that. For the voltage amplification and the kathode follower you can use 807 type's.
Martin Title: Re: Gates Audio Driver Post by: W3GMS on January 11, 2015, 09:56:54 AM Thanks Joe, I failed to see the attachment and those numbers will give a very close idea what could be there to drive the tubes in an audio mode. When troubleshooting a circuit problem and using a 'scope; the reference will always have to be Peak to Peak audio volts on the grids. There is no way, without more inaccurate calculations, to determine what wattage is available, and how that translates to peak to peak volts. The O'Scope is the best piece of test equipment one could have in their shack. I thought there would be some response from radio engineers who may have had some experience with the actual TX. Fred As you know Fred, to deliver the voltage required it has to be able to support the grid current required for class B service. A scope and a sine wave generator will tell you very quickly if the waveform is as it should be. Simple job! Joe Title: Re: Gates Audio Driver Post by: flintstone mop on January 11, 2015, 10:09:16 AM Normally triodes are fed by an kathode follower, voltage amplification take's place before that. For the voltage amplification and the kathode follower you can use 807 type's. Martin Very true...This particular transmitter has a solid state audio driver. |