Jim candela wrote:
John E. Coleman (ARS WA5BXO) wrote:I have been doing some experimenting here on the side and have found a interesting thing that I've seen before but forgotten about. I thought I might share it here with you guys.Geof W5OMR Wrote: I can't believe that no one else has replied to this, on the reflector. From: "Patrick Turner" <[EMAIL PROTECTED]> Subject: Re: SE Output transformer design idea Date: Monday, August 25, 2003 8:06 PM Jim WD5JKO pasted in the following: This from an old thread about single ended audio transformers, and how some folks deal with the high DC flux from the class A audio output tube. In many respects this is the same problem we AM'ers face with push pull modulators where the mod transformer has to bear the RF final plate current without core saturation. Pay attention to the stuff about using a DC constant current source into one winding to buck the flux from the Class A output tube plate current. It may not be practical, but it sure is interesting...
What I surmise about their discussion is that they've basically came to the same conclusion that John has...
More iron is better. For us, that means we need more iron at the Class B Modulator level. All of the Henries of reactance wont matter, if the modulation transformer iron isn't suffiecient enough. Not necessarily for passing low frequencies.. rather, having enough iron in the transformer, to not have to worry about cross-over modulation, ergo, distortion.
Good post, Jim! I enjoyed it, and am looking for more. -- 73 = Best Regards, -Geoff/W5OMR
