Thanks, Doug. I did look at that circuit, and I also looked at a circuit
that used a 4046 Phase Detector. I will definitely consider this one. As
for myself, there is nothing like that sound of the selective fading, to
bring back those youthfull memories of my early DXing days.
On another note......................I could use an Analog Devices AD607. I
tried that chip in the past, but it seemed pretty finicky to work with,
getting the phase shift network to work properly. Maybe I will give it
another try............this would have the Sync Detector self-contained on
only one chip. As with many other chips AD gives an application note for a
10.7MHz based circuit....at 455kHz, you are on your own.

Pete

Doug Smith W9WI wrote in message
...
Pete KE9OA wrote:
option. If we can find a reliable source of Sync Detector chips, that
could
also be an option, but usually, these types of devices are on allocation
with the larger radio manufacturers. I went through just this type of
thing
when I was working for one of the research divisions at Motorola. If we
weren't buying 10,000 devices a week, vendors of some of these specialty
items were not interested.

FWIW there's a sync detector circuit on page 15.34 of the current ARRL
Handbook. (I think it's been in the Handbook for several years) It
uses two NE602s and a NE604, the latter seems to be a FM IF/detector
chip. It's a fair number of parts (may be too expensive simply due to
component count) but I don't think any of them would be particularly
hard to get.

Having used it on the ICF-2010 IMHO you *REALLY* need to consider a sync
detector, dropping other features if necessary. Especially if you hope
to sell to program listeners as well as DXers.
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com