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Old 14th Mar 2019, 10:55 pm   #8
cathoderay57
Nonode
 
Join Date: Oct 2017
Location: Bristol, UK.
Posts: 2,364
Default Re: Marconiphone 855 Silent on 49m

Well, tried it tonight and guess what - no signals on 49m until I put the 6K8G back in. There must be a fault somewhere, as I can't believe it was originally sold with this sort of performance. The design isn't great for stability as the last oscillator anode feed resistor is on the main chassis and there is a wire about 4 inches long going to the wavechange switch and thence the oscillator coils. The only thing that is significantly changed from the original layout is that all 4 HT smoothers were in a waxed box on top of the chassis, long since removed by a previous reparer. Presumably they were all earthed at the same point, whereas now there are several different chassis connections for the individual can electrolytics. I might have a play around with that but otherwise I'm stumped. Cheers, Jerry
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