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40-180. Pushbuttons work, manual tuning doesn't !!!SOLVED!!
#11

(09-17-2015, 11:49 PM)Raleigh Wrote:  After I reflowed my coil terminals, some never did get as low as the schematic said, but all were under 6 or 7 ohms, whereas they were tens of ohms before.  Based on my experience I'd make a wild guess and say that if yours are all under 5 ohms it ought to be OK without reflowing.

No guarantees, but baking could still help.  I was skeptical when Ron suggested baking mine, but I had verified just about everything else--components, tuning condenser, wiring, switch, etc, just as you have, so I didn't have anything else to try.  I don't know whether baking or reflowing solder joints fixed mine, because I didn't test it after baking and before reflowing, but the combination of the two worked like a charm.

If you're confident that the tuning condenser has no shorts between plates, and the switch, wiring, and components (including mica caps) are good, baking might be the next thing to try.  I pulled a 100 uuf mica the other day that measured over 250 uuf.  Conventional wisdom says don't replace micas, but I've had enough bad ones that I don't trust them any more.  I test most of them, and replace quite a few.

I haven't looked at the schematic to see where you're planning to put jumpers, and don't have time tonight, but if the jumpers bypass the band switch and wires, but not the capacitors associated with tuning the oscillator, then you don't have anything to lose, and it might detect some problem.  I'll see if I can glance at the schematic tomorrow and see where you plan to jumper, but by then you'll have already done it!
No, I haven't jumpered it yet. I've looked at the schematic so much lately that it's becoming a blur. I'll wait for your input.

Pat


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RE: 40-180. Pushbuttons work, manual tuning doesn't - by Patrick - 09-18-2015, 09:21 AM



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