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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment.

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Old 10th Sep 2019, 10:33 pm   #41
defender
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Join Date: Dec 2017
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Default Re: Eddystone 840C

Looks like its going to be a long time before it works, if at all
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Old 11th Sep 2019, 4:22 pm   #42
G6Tanuki
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Location: Wiltshire, UK.
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Default Re: Eddystone 840C

Quote:
Originally Posted by Tim View Post
HamishBoxer isn't kidding. The only Eddystone I have had through my hands was very "deaf", mostly caused by those horrible little carbon comp resistors going OOT( mostly high-some very high). I must have changed about a dozen of them.
Check them all, especially the ones over about 10K, particularly if they are designed to have a reasonable potential across them.
Unfortunately some were very hard to get at, as they were under coil banks etc.
Yes - on my 840A the local-oscillator didn't oscillate reliably above about 15MHz; initially I thought the triode of the ECH42 was getting tired but a new one made very little difference.

Replacing the 10K anode-feed resistor with one that actually measured 10K rather than 18K like the original brought things back to life! After that, I replaced quite a few more resistors (screen-feeds, anode decouplers) and the sensitivity improved significantly.

"Steady Eddy" is now my bedside radio - ideal for a bit of nighttime tuning-around when insomnia strikes!
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