[Collins] R-388/51j4 crystal filter

[kirklandb at sympatico.ca]

Best to loosen/tighten up the grounding screws esp note the coaxes are only grounded at one end.

You may have to align the crystal filter by tuning its transformer per the manual.

> From: nq5t at tx.rr.com
> Date: Tue, 17 Sep 2013 13:43:56 -0500
> To: collins at listserve.com; collins at mailman.qth.net
> Subject: [Collins] R-388/51j4 crystal filter
> 
> I have my 51J4 aligned and working well, with a good (on the third try -- thanks, Fern!) 3.1 KHz mechanical filter, Lankford SSB mods, and my Sherwood SE-3 modified to be switchable between 455 and 500 KHz IFs.
> 
> Except for one thing ... sometimes, not all the time, when I turn on the crystal filter to any position the radio sounds like the "divine wind" has started to blow.  A significant noise level appears in the output, somewhat affected in character by the phasing control.  Before I tear into the radio  again, I wonder if anyone has encountered something like this and has a clue where to point the finger?  There isn't anything added to the signal path except for the crystal itself and a parallel 10 pf cap in position 1.  Any thoughts?  A grounding issue maybe?
> 
> Thanks .. Grant NQ5T
> 
> Sent from my iPad
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