I like the feel of that tuning knob............keypads don't do anything for
me. I've done a quick board layout for a VCO.........this way, I can see
what the detector sounds like with continous tuning. If it doesn' hang on to
a .1uV signal, I will move on to another design. Interesting thing I learned
in my Internet research.................sync detectors supposedly exhibit
capture effect, where the strongest signal on the channel will capture the
system, while homodyne detectors do not. This will be an interesting week.
Too bad that the radio manufacturers have made lifetime buys on the
available chips, thus capturing the market on these items. That's
ok.....................I will come up with my own design, eliminating the
need for those specialty chips.
I had considered that Analog Devices AD607, but that chip has got to be the
most unfriendly chip to implement. They have even eliminated the AGC
function in newer iterations of the '607. Even if they hadn't done that, it
is still inexcusable to have a modern day chip that requires external
resistive biasing networks. This goes back to the days of the MC1496.

Pete

Stinger wrote in message
...
I don't know if I would exactly call it useless -- synch detectors can
speed
up the process of tuning. However I agree that nothing beats the
fine-tuning knob (not a button!) / human ear combination for really
nailing
down a signal.

-- Stinger
--
"RFCOMMSYS" wrote in message
...
In my opinion, a synch detector that keeps losing lock on problem
signals
is
useless. Like another poster in this thread said, if you can't design a
good
synch detector (apparently it's not easy to do considering that ICOM
can't
seem
to do it), I would rather have manual ECSS ability (SSB mode with an
extremely
fine tuning (preferably analog) knob)).