[Collins] 51J4 Alignment Question

Grant Youngman nq5t at tx.rr.com
Wed Aug 21 16:26:53 EDT 2013


> Most likely to compensate for tube degradation and minimize time in a service shop.
> 

Probably so.  I haven't compared the with vs. without schematics in detail.  Unless something else changed, the control would only reduce gain.  I don't see any reason to mess with it at this point.  Perhaps I have a fortuitous weak tube(s) somewhere :)

FWIW, a 51j4 with the Lankford product detector and AGC mods (and 4:1 tuning with a weighted knob) works exceptionally well.  I did have to make a couple of minor changes to the Lankford circuit values for best performance in this particular radio, but I am really pleased with the results.  And Sherwood modified my SE-3 to work at 500 khz also -- best of both worlds.

Grant NQ5T


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