No, the AC-4 has the AC4R upgrade. It was keyed in CW mode for too long (not sure how long). What happened is that cable to the keyer came loose when I moved the small table I have it on and the cable came in contact to ground (RCA plug on that end). I was not paying attention. It would not be something I could do if I tried. I'm so angry at myself for leaving it in CW mode or not turning it off and not paying attention.
73, Bob WW3QB --- On Sat, 4/11/09, LEE BAHR <pulsa...@embarqmail.com> wrote: > From: LEE BAHR <pulsa...@embarqmail.com> > Subject: Re: [Drakelist] I Fried my T-4XC > To: "Robert Ladden" <rmlad...@yahoo.com>, drakelist@zerobeat.net > Date: Saturday, April 11, 2009, 10:55 PM > Most likely you did not head warnings > about rebuilding AC-4 power supplies. When the old bias > supply goes out, and it will, the final tubes will draw > unlimited current and you have melt down. Most likely > this is what happened to you. You need to rebuild the > AC-4. I'd use The Heathkit Shops replacement board > AC-4R. Your original final tubes are shot. Don't > try any new tubes until you rebuild the AC-4 power supply. > > Lee, w0vt > > > > ----- Original Message ----- From: "Robert Ladden" <rmlad...@yahoo.com> > To: <drakelist@zerobeat.net> > Sent: Saturday, April 11, 2009 9:23 PM > Subject: [Drakelist] I Fried my T-4XC > > > > > > I had an unfortunate accident. I was using my T-4XC in > CW. I finished but left it in CW mode. I was doing something > else in the basement (where the shack is) when I heard a > fizzle. I saw the T-4XC turn off. I ran to it and saw the > 6JB6's fade from orange. The keyer did something bad, and I > was not paying attention (never leave it in CW mode). Not > good, but I have several spare 6JB6's. The fuse in the AC-4 > blew. I replace the fuse and the 6JB6's and it powers up > again. I try to neutralize the finals on 10m but get little > output and high current. Not good. I try on 40m and it does > tune, but at .4 on the meter I get low output. Trying the > load control gets full output, but pegs the current meter > and I cannot dip the plate. I quickly turn it off. > > > > Cathode resistors test inline at 16 and 30 Ohms. Needs > replacing, but probably not the source of this problem. > Tuning is too weird. > > > > There is no obvious burns on the chokes or anywhere > else, but I fear for the bandswitch back there. Hard to get > a good look. > > > > Is there more I can check? Or is it time for an expert > surgeon? > > > > 73, > > Bob WW3QB > > > > > > > > _______________________________________________ > > Drakelist mailing list > > Drakelist@zerobeat.net > > http://mailman.zerobeat.net/mailman/listinfo/drakelist > > > _______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
