I always wanted to try feedback, from something like the mod monitor, or some sort of detector, and injecting into a low level audio stage....
Have not tried it yet tho... Brett N2DTS > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of John Coleman, ARS > WA5BXO > Sent: Monday, December 01, 2003 1:57 PM > To: [email protected] > Subject: RE: [AMRadio] Re: Modulation transformer ID and repair > > > That's very true Bret. I got an idea about 20 years ago from RCA > and Gates BC XMTRS diagrams. They use direct coupled cathode > followers > to drive the grids of the 833s. Not a lot of trouble > considering the HV > transistors that we have today. The FETs and bipolar transistors have > better characteristics for that sort of thing than the 807s they used > back then. I would never go to a class B or AB2 grids with out my > transistor drivers. > See http://www.qsl.net/wa5bxo/driver1.html > > I have always wanted to try the inverse feed back circuits that > RCA and Gates used on the modulators. But I never have. I > once had the > schematic diagram of the Gates 1KW but lost it in the flood > of 94. I'm > sure there are a lot of ways to do it I just have never taken the time > to try. > > BTW I think your right. I have learned a lot more from stuff > that didn't work out quite right. > I think the most time consuming thing I ever did was to > neutralize a single triode using an inductor from plate to grid (in > series with a blocking cap of course. The inductor resonates > with the G > - P capacitance of the tube. Let me say "It Works very well, > but it is > not my first choice for construction mechanics, plus it has > to be tuned > every time you change frequency.) > > 73, > John, WA5BXO > > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Brett Gazdzinski > Sent: Sunday, November 30, 2003 9:41 PM > To: [email protected] > Subject: RE: [AMRadio] Re: Modulation transformer ID and repair > > The push pull parallel 100TH deck does take quite a bit of > driving power, with the losses, likely close to 20 watts, > which is what the UTC LS grid transformer is good for. > > That may be part of the problem, but class B triodes always > seem to sound less clean than a good AB1 amp. > > Brett > N2DTS > > > > > > _______________________________________________ > AMRadio mailing list > [email protected] > http://mailman.qth.net/mailman/listinfo/amradio
