[R-390] Synchronous AM Detector Kit

[David Wise]

> -----Original Message-----
> From: James A. (Andy) Moorer [mailto:jamminpower@earthlink.net]
> Sent: Thursday, July 24, 2003 10:29 PM
> Subject: Re: [R-390] Synchronous AM Detector Kit
>=20
> This technique is sometimes called "quasi-synchronous"=20
> detection. It works
> just fine as long as the carrier doesn't fade out. Using a=20
> PLL is generally
> preferred because it will "coast" over a momentary fade of=20
> the carrier.
>=20
> The 2001 ARRL Handbook discusses this, starting on page=20
> 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=20
> used for FM
> reception, so it has a square-wave limiter output that can be=20
> used to drive
> the detector.

I have heard this referred to as "Synchrodyne" detection.
That has a nice 1920s sound to it :)
The Sherwood SE-3 can go synch or quasi-synch only; it
has no envelope detector.  In quasi-synch mode, it
does exactly as described above.

73,
Dave Wise