I did find a small round piece that looks like hard polished leather???? It's size is almost an exact match to the tops the slug coils. So if it were a part of a part that's all I've found. I'm done for now. Thanks for all the help everyone.
My MFJ is a 941D. I about died when I found myself trying to load to rig without the coax attached. So I'm just going to save up some money and see about shipping her off for whatever repairs are needed. I see there is a lot I couldn't even solder on my best day anymore. Can't say it enough... thanks. Rick Palmer On 8/21/10, Garey Barrell <k4...@mindspring.com> wrote: > > Rick - > > No problem, better a dupe than not to the list! :-) > > "Fire in the hole" is almost always a 'missing antenna' problem. > Mismatched PA tubes can cause neutralization problems, sometimes with > oscillation and fireworks. You don't say what MFJ tuner you have, but is it > actually rated for 250W? MFJs also have a habit of things melting and/or > coming apart over time. Don't forget that the coax also has a connector on > each end! > > The relay coil is usually wrapped in a 'varnished cambric' tape, red-brown > fabric soaked in varnish, that is heat resistant. Does the relay pull in > ok? It is connected directly to the +250V bus, so a short on the 'wrong' > end of the coil could account for some fireworks. > > Keep us posted! > > 73, Garey - K4OAH > Glen Allen, VA > > Drake 2-B, 4-B, C-Line& TR-4/C Service Supplement CDs > <www.k4oah.com> > > > Richard Palmer wrote: > >> I have tried tuning her up only to find a disconnected coax ( 2 rigs no >> switch ). But when it's connected... it goes into a 300w dummy load. I do >> have to tune the antenna on air though. I noticed on your great CD, while >> looking for a titanium cap, that the relay there is wrapped in what looks >> like asbestos. I'm not certain mine is there... should it be??? >> >> All three PA tube are Sylvania. I run Times LMR400 UF... it's new but my >> old MFJ might be causing me problems. I bought it used over ten years ago. >> It seems to be ok with 100w but maybe the Drake stresses it out. That is on >> my have to replace next list. I'm not even going to try it with the drake >> again. >> >> Thanks everyone for the great ideas. When this get this sussed out you'll >> be the first to know. >> >> Rick Palmer >> Sorry for the dupe Garry >> >> On Fri, Aug 20, 2010 at 10:34 PM, Garey Barrell <k4...@mindspring.com<mailto: >> k4...@mindspring.com>> wrote: >> >> Richard - >> >> The fact that it didn't tune indicates that perhaps the antenna >> was either not connected (relay?) or wrong band? or bad coax, or >> ... Possibly arcing in the relay contacts or coil. >> >> What is the BIAS current? It should be 100 mA, if it's now 65 mA >> or so you may have lost a final tube. >> >> Really not much to flame in the PA cage. You could get corona on >> variable cap plates, again due to mismatch, but that is typically >> an ozone smell. A parasitic could have fried one of the parasitic >> suppressors on the PA plate caps. Are all three PA tubes from the >> same manufacturer? >> >> 73, Garey - K4OAH >> Glen Allen, VA >> >> Drake 2-B, 4-B, C-Line& TR-4/C Service Supplement CDs >> <www.k4oah.com <http://www.k4oah.com>> >> >> >> >> Richard Palmer wrote: >> >> My TR-4 did not want to tune... it caught on fire that looked >> like it was at the PA section probably around the relay. All I >> could really do was grab switches and plugs faster than >> anything I've done in the last twenty years. >> >> The smoke was not the conventional electric smell. It was very >> acid and burning. I sorta took in a nose full doing the above >> and felt high, in a bad way. I just got around to looking at >> it and can not find any burnt or distorted part. There is >> absolutely no sign of soot or heat anywhere. Seeing this I >> tried to tune her up again. I was getting a very solid 4.5 for >> the plate current. Now it's only 3. Is it possible (likely) >> that I "smoked" one of my PA tubes? >> >> Thanks in advance, >> Richard Palmer >> KB8NXO >> >> >> >> > _______________________________________________ > Drakelist mailing list > Drakelist@zerobeat.net > http://mailman.zerobeat.net/mailman/listinfo/drakelist > >
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