[R-390] Synchronous AM Reception

Fri, 22 Mar 2002 05:09:22 -0800 (PST)

I've never used that method, but it sounds to easy to be true.  Seems like a
true sync detector needs to measure and actively alter the BFO frequency needed
to keep things straight.

The best way is to use a Sherwood SE-III or similar device, but they are
expensive and are getting hard to find.

I made a poor boy hookup recently, using a Sony portable with sync detect for a
detector, tuning it to 455 khz, couple the IF signal to it with a whort wire
nearby, and then route the line output to an amp.  Worked well on a 390A and
also on a 51J3 (500 kcs IF).  Gives you selectable sideband sync detection in a
small box with little fuss.  I already had the radio.  You can probably get a
Sony 2010 or 7600G?? on ebay.

There is a kit out there offered by Steve Johnson, and the ARRL handbook has a
homebrew detector.

Bonne chance!

Tom N5OFF
--- Fraser Bonnett <[email protected]> wrote:
> Having just recently got my R-390A back out of storage, I find myself
> interested in MW DX'ing again.  I have re-read two articles on modifying the
> R-390A to acheive carrier synchronous demodulation, and was wondering if
> anyone has any experience with it, and if it is worth attempting:
> 
> An NRC reprint from 1992 uses:
>     a coil of wire around the anode of V508
>     100K (or 47K) resistor
>     a 5-50 pf trimmer grounded to the carrier meter adjust nut
>     a 47K (or 22K) resistor in series and connected to pin socket 1 of V505
> 
> 
> Once it's set up, how do you use it, what effects do you observe.
> 
> 
> Fraser, W3UTD
> 
> _______________________________________________
> R-390 mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/r-390

__________________________________________________
Do You Yahoo!?
Yahoo! Movies - coverage of the 74th Academy Awards�
http://movies.yahoo.com/