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Title: P/P Parallel 6V6 Driver Post by: W9ZSL on March 29, 2015, 05:18:32 PM Just scored an NOS Stancor A-4762 15 watt driver iron on eBag. Should work well with this circuit which I've discussed before. Should be good for at least 10 watts...more than enough to drive a pair of 811A's when substituted for the Merit iron shown in the diagram. Comments?
Title: Re: P/P Parallel 6V6 Driver Post by: W7TFO on March 29, 2015, 07:41:02 PM I don't see any parallel going on in that schematic... ???
73DG Title: Re: P/P Parallel 6V6 Driver Post by: W9ZSL on March 29, 2015, 10:21:38 PM So what is it then? Not that it matters.
Title: Re: P/P Parallel 6V6 Driver Post by: KA2DZT on March 29, 2015, 11:12:23 PM Push-pull 6V6 driver. P/P parallel would be four 6V6s
Title: Re: P/P Parallel 6V6 Driver Post by: Opcom on March 30, 2015, 06:29:35 AM It would not hurt to use four 6V6s if the A-4764 transformer can take the current from them. It would probably help the drive regulation.
Title: Re: P/P Parallel 6V6 Driver Post by: W3RSW on March 30, 2015, 09:34:49 AM Probably just minor confusion when quick glancing at the diagram. The 6sj7 phase inverters appear to be in parallel with the 6v6's.
My first thought was it was ZSL's intention to add two more 6v6's and understood. We seem to parse everything to death. Title: Re: P/P Parallel 6V6 Driver Post by: N2DTS on March 30, 2015, 09:51:07 AM Could you not just use a pair of 6l6's instead of four 6v6's?
It would not hurt to use four 6V6s if the A-4764 transformer can take the current from them. It would probably help the drive regulation. Title: Re: P/P Parallel 6V6 Driver Post by: KA2DZT on March 30, 2015, 10:08:49 AM I drive my 811As with a single 6L6 using a 25W mod xfmr and a lot of feedback. Works FB and I have plenty of audio. I used my own design.
Title: Re: P/P Parallel 6V6 Driver Post by: VE3LYX on March 30, 2015, 01:18:41 PM Internal resistance (in parallel are less then any single in the parallel set.) One big tube can raise this and it is of no real concern in most situations however when series cathode modulating old cathode keyed rigs on an existing PS(and I realize you are not)one has all the sudden the AH HA moment when you realize that is why. Previous to that moment I never understood why either. Voltage drop across the tube/s is what I was fighting. It was not apparent to me before this experience.
don Title: Re: P/P Parallel 6V6 Driver Post by: W9ZSL on March 31, 2015, 11:54:39 AM I could consider 6L6's but the driver transformer is just 15 watts. The circuit with the 6V6's is good for 12 watts. Since I have a couple 6V6's, I'll try that first. I'd really have to loaf 6L6's to not overload the iron. AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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