[R-390] Synchronous AM Detector Kit

Fri, 25 Jul 2003 08:23:08 -0400

I believe there was an article in Popular Electronics
for a solid state synchonous AM detector add-on
unit.  This was many years ago, and I have a copy
of it in storage.  Date of the article, unknown,
sorry.

73
Sheldon
WA4MZZ

"James A. (Andy) Moorer" wrote:
> 
> This technique is sometimes called "quasi-synchronous" detection. It works
> just fine as long as the carrier doesn't fade out. Using a PLL is generally
> preferred because it will "coast" over a momentary fade of the carrier.
> 
> The 2001 ARRL Handbook discusses this, starting on page 15.30. There is a
> circuit there that allows you to switch between synchronous and
> quasi-synchronous detection. It uses a chip that is normally used for FM
> reception, so it has a square-wave limiter output that can be used to drive
> the detector.
> 
> I haven't built that particular circuit, so I don't know how well it works,
> but I enjoyed reading the article.
> 
> James A. (Andy) Moorer
> www.jamminpower.com
> 
> ----- Original Message -----
> From: "Joe Reda" <[email protected]>
> To: <[email protected]>
> Sent: Thursday, July 24, 2003 9:59 PM
> Subject: Re: [R-390] Synchronous AM Detector Kit
> 
> > At 07:59 AM 7/24/2003 -0700, Dennis L. Wade wrote:
> >
> > >         And for those of us who are thinking about what path to get
> there on
> > >(excuse the extended metaphor), anyone have any/know of any good
> > >designs to homebrew?
> >
> >
> > I found this one:
> >
> > http://www.radio-electronics.com/info/receivers/sync_det.htm
> >
> > I'd be curious to know what y 'all think of this.  I'd always wondered if
> > you could send the signal
> > through a limiter or two to surpress the modulation, and then use that as
> > your input to the mixer or
> > product detector and so achieve sync detection.  This idea (near the
> bottom
> > of the page) seems
> > to be just that.
> >
> > What would you use for the limiter?  FM-type limiter circuits, such as
> > those that use 6AU6s beloved of
> > so many receiver designers?
> >
> >
> > Joe W9TXU
> >
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> 
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