I finally got the AD607 sync detector running very well. I was able to widen
the loop bandwidth and gain a good phase margin. The original appnote used
an earlier version of this chip that had an AGC detector. The RSSI pin was
decoupled with a 1.5uF cap. I didn't realize that this cap would be
necessary with the newer chip. Anyway, I decided to give this measure a try
this morning. The howling noises vanished, leaving a clean audio signal. One
of the Philips support people stopped over today, along with the Arrow rep.
He was impressed with the adjacent channel selectivity. This sync detector
circuit adds another 8 poles of selectivity at 455kHz, giving the complete
system 14 poles at 455kHz. Once you tune a local station out of the I.F.
passband, it isn't there anymore.
Compared to the TDA1572's low distortion envelope detector, this detector is
smoother sounding. I think I've got a winner her. In the next couple of
days, I should be hearing from the Philips folks............they may be able
to help me with the implementation of the 1572's on-board oscillator, using
a fundamental mode crystal.
The boss (software engineer) was working on the interface circuitry over the
weekend, and came along with quite a few ideas. We have decided to add an
RS232 interface to the receiver; this way, folks have the additional option
of computer control. We should have a pretty cool GUI to go along with it.
Stay tuned!

Pete

On Tue, 06 Jan 2004 07:23:53 GMT, "Pete KE9OA"
wrote:


The boss (software engineer) was working on the interface circuitry over the
weekend, and came along with quite a few ideas. We have decided to add an
RS232 interface to the receiver; this way, folks have the additional option
of computer control. We should have a pretty cool GUI to go along with it.
Stay tuned!

Pete


As an EE, I'm a little jealous!

RS232 is nice but I'd like to see a receiver with an ethernet port
that can be set to user-adjustable IP address.

Also an embedded web server that would also stream audio would be
nice.

Ten Tec........ that would be a nice update for the RX-320!

Joe E.

Joe Esposito wrote in message
...
On Tue, 06 Jan 2004 07:23:53 GMT, "Pete KE9OA"
wrote:


The boss (software engineer) was working on the interface circuitry over
the
weekend, and came along with quite a few ideas. We have decided to add an
RS232 interface to the receiver; this way, folks have the additional
option
of computer control. We should have a pretty cool GUI to go along with
it.
Stay tuned!

Pete


As an EE, I'm a little jealous!

RS232 is nice but I'd like to see a receiver with an ethernet port
that can be set to user-adjustable IP address.

A big reason for the RS232 interface will be for initially setting things up
at the factory..............the GUI driven program will be a bonus that we
will throw in.

Also an embedded web server that would also stream audio would be
nice.

Those web server programs are pretty cool..............some of the folks
were doing that back at Motorola.

Pete


Ten Tec........ that would be a nice update for the RX-320!

Joe E.