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.

The system maintains lock through the entire I.F. bandpass. I haven't
measured the capture ratio.............probably a little bit further
on.................

Pete

starman wrote in message
...
Pete KE9OA wrote:

I finally got the AD607 sync detector running very well. I was able to
widen
the loop bandwidth and gain a good phase margin.

snipped

Pete,

How far can you detune the input signal before losing lock on the sync'?
What is the capture ratio?


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I am not sure about that, but it sounds like a good idea. As far as the
interface, I am not sure what platform they will be using. We will probably
use some sort of DOS program for setting up the initial parameters. Stay
tuned!

Pete

Gregg wrote in message
news:OHtKb.85811$6b2.25573@edtnps84...
Behold, Pete KE9OA signalled from keyed 4-1000A filament:

snip

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

Hi Pete!

Since you and your company have been so kind as to make this project so
open, will us *nix programmers have access to the software protocol so we
can make *nix software to control the RX too?

This is assuming that your boss only plans a Windows interface ;-)

Really appreciate the progress reports!

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

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.

Behold, Pete KE9OA signalled from keyed 4-1000A filament:

I am not sure about that, but it sounds like a good idea. As far as the
interface, I am not sure what platform they will be using. We will
probably use some sort of DOS program for setting up the initial
parameters. Stay tuned!

Pete

If it's DOS, we can easily emulate that and compatability won't be too
much of a problem ;-)

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

That sounds good, Gregg.................that stuff is over my head. I just
stick to the easy stuff, the RF and the analog design!

Pete

Gregg wrote in message
news:BdHKb.179894$ss5.41255@clgrps13...
Behold, Pete KE9OA signalled from keyed 4-1000A filament:

I am not sure about that, but it sounds like a good idea. As far as the
interface, I am not sure what platform they will be using. We will
probably use some sort of DOS program for setting up the initial
parameters. Stay tuned!

Pete

If it's DOS, we can easily emulate that and compatability won't be too
much of a problem ;-)

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

Pete KE9OA wrote:
I am not sure about that, but it sounds like a good idea. As far as the
interface, I am not sure what platform they will be using. We will
probably use some sort of DOS program for setting up the initial
parameters. Stay tuned!

I think what Greg is getting at (and I'd favor) is releasing the command
protocol to the public so that users can write their own interface
software. (either to support alternative operating systems like Linux,
or to provide software functions that you may not have thought of. Some
such programs have been released for some of the Ten-Tec radios, for
example.)
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

Pete,

Have you heard anything about how this receiver will be marketed? Is
there a distributor on board?


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Hi,
We may market this unit ourselves. I contacted both Universal and
Grove, and the responses from both of them were lukewarm. I am the new kid
on the block, so they don't know anything about me, so I can't really blame
them for their lack of interest. I don't think that we will need anybody for
a distribution network, but who knows? Our company is doing a good job
selling out current products through our website.
Anyway, if any of you have the XM Satellite receivers, they are using the
AD607s, so you can get an idea of the recovered audio quality. I did some
listening to the detector last night, and where the envelope detector was
clearly exhibiting distortion on faded signals, the sync detector maintained
clean audio quality almost all the way down into the noise level. Once the
signal almost completely faded out, there was some distortion, but it was
very minimal. The AD607 recovers is less than 20uSec, so settling time is
not an issue. I still would like to eliminate the slight modulation I am
seeing on the limited signal; once this is done, I will be able to narrow
the loop bandwidth. If it is too narrow, the system will go out of lock on
modulation peaks.
Right now, I have the loop bandwidth set at 58kHz, and the system is super
clean. Still needs some work, but I am very close.

Pete

starman wrote in message
...
Pete,

Have you heard anything about how this receiver will be marketed? Is
there a distributor on board?


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