[R-390] Diversity with an A and a non-A?

[William J. Neill]

Well, here at home, I’m currently running dual and frequency diversity with my Collins R-390A and Collins 51J4 and have been doing so since at least 1970 and am still going full business but there sure isn’t much traffic to copy as everything has gone to SATCOMS or subsea cables.



Bill Neill
Conroe, Texas

> On Feb 24, 2021, at 14:56, Fred Moore <fred_moore at usa.net> wrote:
> 
> Paul, 
> 
> I don't think you need to worry about any difference in propagation delay
> between the two receivers.  gain matching is important.  check schematics to
> confirm that the diode connection is done the same way (almost certainly is
> compatible).  Then it can be tried. 
> 
> -Fred
> 
> ------ Original Message ------
> Received: Wed, 24 Feb 2021 07:40:57 PM GMT
> From: Paul Staupe <staupe at gmail.com>
> To: fred_moore at usa.netCc: Collins R-390 HF Receiver List
> <r-390 at mailman.qth.net>
> Subject: [R-390] Diversity with an A and a non-A?
> 
> I read through the Pearls just now and didn't see any references to
> diversity reception with a R-390A and a R-390.  I have one of each, so I'd
> like to try it out.
> 
> Both receivers are capable of diversity reception and I imagine it's
> possible to do.  I'm wondering if the phase delay in the mechanically
> filtered A model would be significantly different enough than the L/C
> filtering in the non-A to make a noticeable difference in this configuration
> vs. a set up with identical models?
> 
> Thanks,
> 
> Paul W0AD
> Minneapolis
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