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40-190 RF Problems - Need Help
#9

First and foremost guys I'm just a hobbyist. I've been working on antique radios for about 6 years now. Retired early after 27 years with Boeing as a tech due to a bad heart. 1st attack at 43. I'm no engineer but I am familiar with my test equipment (listed below) and know how to use it. I took 4 years of electronics in high school in the 60's and many classes after that just to keep up with the ever changing technology that I needed to perform my job. It had nothing to do with vacuum tubes. I've fallen in love with this hobby and work at it 7 days a week just because I'm not the kind of guy to sit on his butt. I work on tons of radios and every once and a while I have one like this that I just get stuck on and need help. Most of the problems I encounter are due to mistakes made by me in wiring the set back up. This is why I started having my schematics blown up to 11X17 and using a highliter to mark off every part or wire that goes back into a set. It's helped a lot. But once I've gone over that wiring 2 or 3 times and everything is correct I start looking at other areas where the problem could be. But I'm not a genious with these things and I don't believe I ever will be. Here's what I have.
Fluke 179 Multimeter
Elenco CM-1555 Cap Meter
Eico 320 Sig. Gen.
Protek 9100 Freq. Counter
Variac
Heath IT-21 Tube Tester
Simpson 260 Series 6P
I used to have a nice digital Tektronix o-scope but I never used it so I sold it.

Last night I removed the pushbutton assy., coils and padder strip to get under it to check out my work. I'm gonna go do that now. As for how I tested the micas I just had them isolated from the circuit and measured them with my cap meter. As you can see I don't have a bunch of sophisticated equipment. The 2 370pfd caps that were questioned read so close to that, I left them in as I did with all the micas in this set. All well within tolerance. I do understand that these components can be breaking down when power is actually on the set but I don't see a lot of bad mica caps.

EDIT: I've installed all my jumpers to the PB assy. and it's out of the way. Went back over the schematic again and verified all my component and wiring connections and I don't find anything installed incorrectly. Even compared these connections with my -185 that's working. If it is the oscillator then I'm not sure what's wrong with it. Resistance readings across all the pins on it match what's on the schematic and the osc. in the -185. For the heck of it I cleaned all my Loctal sockets again. Pins on the tubes are scraped nice and shiny with a sharp blade. Still have the same problem.

Thanks for the help,
Pepper

"It's Nice To Be Nice To The Nice"
Major Frank Burns Mash 4077th


Messages In This Thread
40-190 RF Problems - Need Help - by Pepperoni - 10-15-2011, 02:47 PM
Re: 40-190 RF Problems - Need Help - by Pepperoni - 10-15-2011, 07:00 PM
Re: 40-190 RF Problems - Need Help - by Arran - 10-16-2011, 09:11 PM
Re: 40-190 RF Problems - Need Help - by Pepperoni - 10-16-2011, 10:09 PM
Re: 40-190 RF Problems - Need Help - by Arran - 10-16-2011, 10:19 PM
Re: 40-190 RF Problems - Need Help - by Pepperoni - 10-17-2011, 11:30 AM
Re: 40-190 RF Problems - Need Help - by codefox1 - 10-17-2011, 03:19 PM
Re: 40-190 RF Problems - Need Help - by 7estatdef - 10-17-2011, 04:08 PM
Re: 40-190 RF Problems - Need Help - by Pepperoni - 10-17-2011, 04:32 PM
Re: 40-190 RF Problems - Need Help - by Pepperoni - 10-18-2011, 12:49 PM



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