Rick, Just a thought on the osc circuit. You could always disconnect the osc board and use a signal generator to feed the grid of the 6146. This will let you test out the remainder of the transmitter on the AM broadcast freq.
I would think that the crystal osc will be removed when you move it to 75M, so fixing it may not be worth the effort. 73's Roger KC8OPP --- Rick Brashear <[EMAIL PROTECTED]> wrote: > Well... I have investigated the printed circuit > board on the 1R2 on > which the crystal ovens are mounted and find there > have been several > modifications and/or repairs made through out this > old girls life. My > intention, as advised by much more knowledgeable > people on these > transmitters, is to put it back to it's original > state, be sure it's > operating at the original specifications, then begin > the conversion to > 75 meters. My concern is that some of these mods > may have been handed > down by RCA and should possibly be left in tact. > Does anyone know of > any modifications that RCA issued concerning this > portion of the > transmitter? I have found traces cut and spliced to > other traces, a > small variable capacitor replacing a compression > trimmer and two of the > three crystal sockets more or less taken out of use > with that fact > marked in pencil on the board. My inclination is > these are repairs made > due to failure of components, but with no > documentation on the repairs > it's very difficult to be sure. The board is badly > scorched beneath the > 4000 ohm 10 watt resistor, but I have read this is a > common issue. > There is no trace damage to the board from the heat. > > Any advice will be very much appreciated. For those > who subscribe to > more than one list, I apologize if you receive this > post more than once, > but I want to reach the largest audience possible > for assistance and advice. > > Thanks, > Rick/K5IZ > > > > > ______________________________________________________________ > AMRadio mailing list > Home: > http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul > Courson/wa3vjb > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
