I have an rca bta-1r (just got it) and I wonder how much drive you need for the circuit as you have it?
John (N1FCU) --- "KC8OPP Roger S." <[EMAIL PROTECTED]> wrote: > Rick, > > Here is what I did to bring the RCA to 160/80/40M. > > First thing is get a copy of the "Radio Handbook" by > William Orr, W6SAI. This book has all the answers. > > I started by bringing the transmitter up on the freq > the radio station used. I cleaned and repaired as > required. I checked all voltages against the book, > swept the audio section and made more repairs. When > it works as advertised by RCA, then you can start to > have fun. > > I removed the master osc board and built a box for > the > grid input circuit. I used link coupled coils that > are switched in for each band and drive the grids > with > a Kenwood TS-520. The same band switch is used to > changed the taps on the final tank coil. The > winding > data for the grid coils was borrowed from the 16th > edition of the Radio Handbook. I did install a grid > coil for 20M, but have never tried the transmitter > on > 20M, wishful thing I guess. > > The final tank that RCA installed was completely > removed and I used the "L" coil for my tank. Vac > variable caps were used for Tune and Load. I put > the > circuit together on the bench to find the right taps > on the coil. Use a non inductive resistor in place > of > the tube that is equal to the calculated plate load > and then a antenna analyzer connected to the output. > > This put me in the ball park and just some minor > changes were needed when the tank circuit was > installed in the cabinet. > > The cabinet measured 32 inches deep and 34.5 inches > wide when I removed the meters and switches, just > enough room to fit through the doors. I would guess > that in the stripped down mode the cabinet still > came > in around 300 pounds or so. > > Hope this helps a bit, I will look forward to > hearing > your RCA on the air. > > > Good Luck and 73's > Roger > KC8OPP > > > --- Rick Brashear <[EMAIL PROTECTED]> wrote: > > > Wow! Thanks Roger. Great pictures documenting > the > > move and > > restoration. I would be very interested in the > > modifications you made > > to the tuning circuitry. At this point I only > plan > > on having mine setup > > for 75 meters, but it is nice to know someone who > > has successfully > > modified one to accommodate 160, 80, 40 and 20 in > > case I want to expand > > the coverage. > > > > Could you tell me exactly how wide the cabinet was > > after you removed the > > meters, switches, etc.? I'm afraid I'm going to > > have to back my truck > > through the side of the house to get mine inside! > > Also, how much do > > suppose it weighed when all of the iron, doors and > > everything else > > removable was removed? > > > > Thanks for sharing your story, pictures and > > expertise. I can hardly > > wait to get started on mine. > > > > 73, > > Rick/K5IZ > > > > > > KC8OPP Roger S. wrote: > > > > >Rick, > > > > > >I have a BTA-1R that is set up for 160/80/40M. > > Here > > >is a link to some pictures of the process. > > > > > >http://photos.yahoo.com/kc8opp > > > > > >If I can help in any way let me know. > > > > > >Good Luck. > > > > > >73's > > >Roger > > >KC8OPP > > > > > > > > > > > > > > > > > > > ______________________________________________________________ > > AMRadio mailing list > > Home: > > http://mailman.qth.net/mailman/listinfo/amradio > > Help: http://mailman.qth.net/mmfaq.html > > Post: mailto:AMRadio@mailman.qth.net > > 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 > ______________________________________________________________ > AMRadio mailing list > Home: > http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > 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
