Model 71 oscillator

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Model 71 oscillator

WB5NEN
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Posts: 13
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Joined: Aug 2020
City: Corrales State, Province, Country: NM

09-07-2020, 05:16 PM

Steve and Terry,

It’s working. I noticed that, by touching the grid cap on the oscillator, it sprang to life. But next time, it was dead until I touched the grid cap again. Rinse, repeat. This struck me as odd, so I paralleled a resistor across the 15k cathode dogbone resistor (which actually measured 12.5K.) The current value of these two resistors is 8.4K. Right now, that oscillator starts up automatically every time I turn the set on. But I’m leaving it on the bench for awhile. Fingers crossed.

I did remove and examine the oscillator coil. I just wanted to see it. It’s fine, as I suspected, because the large oscillator coil showed continuity and 4.3 ohms. The “input” coil From the RF stage in this radio is just a turn of wire...and one end is unterminated. It just floats.

Now, can someone educate me on this cathode resistor...I’m not clear on what I’ve done, or why. Sorry for the ignorance.

And thanks, gents.

Richard

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Messages In This Thread

Model 71 oscillator - by WB5NEN - 09-06-2020, 02:17 PM

RE: Model 71 oscillator - by Steve Davis - 09-06-2020, 10:16 PM

RE: Model 71 oscillator - by Radioroslyn - 09-07-2020, 08:39 AM

RE: Model 71 oscillator - by WB5NEN - 09-07-2020, 05:16 PM

RE: Model 71 oscillator - by WB5NEN - 09-07-2020, 07:32 PM

RE: Model 71 oscillator - by Radioroslyn - 09-07-2020, 07:53 PM

RE: Model 71 oscillator - by WB5NEN - 09-07-2020, 10:15 PM

RE: Model 71 oscillator - by WB5NEN - 09-08-2020, 01:57 PM

RE: Model 71 oscillator - by Radioroslyn - 09-08-2020, 07:58 PM

RE: Model 71 oscillator - by Steve Davis - 09-08-2020, 11:47 PM

RE: Model 71 oscillator - by WB5NEN - 09-09-2020, 04:19 PM

RE: Model 71 oscillator - by Radioroslyn - 09-09-2020, 06:57 PM

RE: Model 71 oscillator - by RodB - 09-09-2020, 07:00 PM

RE: Model 71 oscillator - by Radioroslyn - 09-09-2020, 08:49 PM

RE: Model 71 oscillator - by WB5NEN - 09-09-2020, 10:18 PM

RE: Model 71 oscillator - by Radioroslyn - 09-10-2020, 08:07 AM

RE: Model 71 oscillator - by WB5NEN - 09-10-2020, 08:50 AM

RE: Model 71 oscillator - by RodB - 09-10-2020, 08:57 AM

RE: Model 71 oscillator - by Radioroslyn - 09-10-2020, 10:34 AM

RE: Model 71 oscillator - by rfeenstra - 09-10-2020, 04:46 PM

RE: Model 71 oscillator - by WB5NEN - 09-10-2020, 10:43 PM

RE: Model 71 oscillator - by rfeenstra - 09-11-2020, 09:38 AM

RE: Model 71 oscillator - by WB5NEN - 09-11-2020, 10:07 AM

RE: Model 71 oscillator - by rfeenstra - 09-11-2020, 12:54 PM

RE: Model 71 oscillator - by rfeenstra - 09-11-2020, 01:05 PM

RE: Model 71 oscillator - by WB5NEN - 09-14-2020, 06:58 PM

RE: Model 71 oscillator - by Radioroslyn - 09-15-2020, 09:46 AM

RE: Model 71 oscillator - by WB5NEN - 09-15-2020, 12:00 PM

RE: Model 71 oscillator - by WB5NEN - 09-18-2020, 07:29 PM

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