MAc wrote:
To clarify - the idea is to build very simple receiver - Not "play with
quadrature detector". AD607 look simply and small

Andy writes:

While I agree with everything MAC wrote, I think a point is being
missed.
A Quadrature detector is normally used only for FM demodulation. It
accomplishes this by limiting the signal and applying it to one port
of a 90deg detector. If the limited signal is shifted 90 degrees
(narrow
band), the quad detector will detect FM... If the limited signal is
shifted
ZERO degrees, the quad detector will detect AM, and in a much more
linear way than a diode type detector......

With CW, there would be no signal to zero beat with, and no audio
note would be formed.... Exactly the same with SSB....all the output
would be "DC"...

Mac's explanation is correct for an IQ detector... In this case a
local
signal EQUAL to the suppressed carrier of the SSB signal has to
be supplied..... I don't know how a local carrier can be synchronized
to
a SSB carrier that, if done really well, doesn't exist......

In Homodyne receivers, it is easy, since the transmit signal can be

the LO signal..... Otherwise, it has to be "guessed" at..... With
really
really really stable local oscillators, the guess can be really close,
and
the difference will creat an error that is so small it doesn't
matter... But,
since you don't know the incident phase of the received signal, you
have to do both I and Q and shift the IF by 90 degrees and sum (or
difference, depending whether you want USB or LSB) the outputs of
the two channels...... For SSB detection, the RF port is NOT shifted,
the LO port is both 0 and 90 degrees, and the IF port ( I and Q) are
shifted 90 and combined........

It is a hell of a lot easier to "approximate" the LO, and shift it
manually
until Donald Duck starts sounding human.... In older SSB rigs, this was

called a "clarifier" control..... It isn't necessary in many modern
systems
with really really really good TCXOs and stuff....

Just my two cents worth.... If anyone disagrees, I'd be happy to
learn from them where my explanation is wrong..... but I warn you,
it ain't far wrong.... cause it worked for me for many many years
in designing receivers for both commercial and military products
....:)))))

Andy in Eureka, W4OAH ( retired comm/radar engineer and ham for 45
years )

AndyS wrote:
A Quadrature detector is normally used only for FM demodulation.

Yes.

but (from Analog Devices):
"...Applications of the AD607 include narrowband systems with a high
first IF (21.4 MHz to 300 MHz) and a second IF at 10.7 MHz, 455 kHz, or
450 kHz. These include Dual Conversion IS136, GSM, TETRA, and MSAT
Receivers; and Single or Dual Conversion VHF and HF AM, SSB, CW, or QPSK
Receivers... "

But :-) I did not find any SSB application :-( So I need an example.




Just my two cents worth.... If anyone disagrees, I'd be happy to
learn from them where my explanation is wrong..... but I warn you,
it ain't far wrong.... cause it worked for me for many many years
in designing receivers for both commercial and military products
...:)))))


Andy Thanks for your cents, rather dollars.

PS there is internal quadrature pll in ad607.

MAc

Andy Thanks for your cents, rather dollars.

PS there is internal quadrature pll in ad607.

MAc


Andy responds;

Ok.. I admit that I didn't go find the AD607 and study it before
replying
to Mac... However,,, I'll bet you a dollar that the fellow who wrote
the
app note that Mac refers to has a hell of a lot less experience than
either Mac or myself..... not that I would expect a young app note
writer to overstate the applications of his product ( big damn grin
)...
The AD606 really makes a great tie-tac if you glue an alligator clip
to it, tho I've never actually seen one for sale... :)))))))

if the gilbert cell, or single ended long tailed pair multiplier
used as a
quad detector allows external coupling to the ports, it can be used as
a BFO for CW or SSB,..., HOWEVER, having a limiting stage in the
linear path of such a device is NOT a great idea.... Sure, it can be
made
to work, but..... well, heck... I've built a LOT of things that were
really
bad ideas, and I try not to duplicate them again, or tell others about

them.... especially in app notes that I've made input to......
I've seen the MC3372 used as an SSB receiver in either Ham Radio
or some such.... and I never seriously considered doing it myself since
the limitations were so obvious....

An 811A can be used a a product detector also, but the
manufacturers
don't advertise it as such,...... because it is a REALLY BAD idea....
If a fellow wants a simple CW/SSB receiver, a much better idea is to
use something like an NE602..... I've done that, for a home project ,
and
it works OK,..... but certainly not something I'd try to produce as a
receiver for Bendix, Texas Instruments, or Raytheon...... There's a
limit
to how far one should stretch an application.....

Thanks Mac, for your input. I bet we agree on almost
everything.....

Andy W4OAH

Ok.. I admit that I didn't go find the AD607 and study it before
replying.....

.....HOWEVER, having a limiting stage in the
linear path of such a device is NOT a great idea
---------------------

Andy,

You really should go and read the data sheet on the AD607.

1) It's a linear component with no limiter stages
2) It has an "I-Q" detector, not a "quadrature detector".

Comparing it to the MC3372, or any other FM detector chip, is as far off
base as comparing it to an 811.

However, having said all that, I think we would agree that there are better
and simpler solutions for amateur SSB and AM applications.


Joe
W3JDR


"AndyS" wrote in message
oups.com...

Andy Thanks for your cents, rather dollars.

PS there is internal quadrature pll in ad607.

MAc


Andy responds;

Ok.. I admit that I didn't go find the AD607 and study it before
replying
to Mac... However,,, I'll bet you a dollar that the fellow who wrote
the
app note that Mac refers to has a hell of a lot less experience than
either Mac or myself..... not that I would expect a young app note
writer to overstate the applications of his product ( big damn grin
)...
The AD606 really makes a great tie-tac if you glue an alligator clip
to it, tho I've never actually seen one for sale... :)))))))

if the gilbert cell, or single ended long tailed pair multiplier
used as a
quad detector allows external coupling to the ports, it can be used as
a BFO for CW or SSB,..., HOWEVER, having a limiting stage in the
linear path of such a device is NOT a great idea.... Sure, it can be
made
to work, but..... well, heck... I've built a LOT of things that were
really
bad ideas, and I try not to duplicate them again, or tell others about

them.... especially in app notes that I've made input to......
I've seen the MC3372 used as an SSB receiver in either Ham Radio
or some such.... and I never seriously considered doing it myself since
the limitations were so obvious....

An 811A can be used a a product detector also, but the
manufacturers
don't advertise it as such,...... because it is a REALLY BAD idea....
If a fellow wants a simple CW/SSB receiver, a much better idea is to
use something like an NE602..... I've done that, for a home project ,
and
it works OK,..... but certainly not something I'd try to produce as a
receiver for Bendix, Texas Instruments, or Raytheon...... There's a
limit
to how far one should stretch an application.....

Thanks Mac, for your input. I bet we agree on almost
everything.....

Andy W4OAH

W3JDR wrote:
Andy,

You really should go and read the data sheet on the AD607.


Andy replies,

You're right. I should have dug a little further before I started
rattling off "the world according to Andy"....
When the OP started with the "quadrature det" question and
the reply was concerning I/Q , I just jumped right in...

Sorry I wasted your time......

Andy W4OAH

AndyS napisa?(a):
I bet we agree on almost
everything.....

Generally Yesss

But (always but) :-))))

I never used mc3372 as ssb rx, but permanently used mc3362.
But... - mc3362 id dual conversion RX and i used second mixer as a
product detector leaving original fm detector "out of business".
I am not good in quadrature detectors, and i don't know what
(technically) is mixer (rather mixers) in ad607. I have only 1 piece of
IC, it's surface mount, and I'm afraid, that if I use it in my test
board I will have nothing to use in my receiver.

Of course I used ne602/612 in many constructions, (genetally trx with
switched BFO/VFO - Atlas idea), but this time the idea is to use as low
elements as possible to build a rx with "quite good" performance.

Serious (other or better ;-) ) idea in my wokshop is TGX with1st mixer
on fst3125 with companion of ad600 IF ampli (only one) in typical
application (application note with simple ad590 and one transistor AGC)
- not this "high performance agc system from Exp. Methods...

On the other hand - it is the best way in our HAM life - to use parts in
the way, which was not inntended by "creators". It's a part of our love
to ham radio :-)

Nice and inspirating talk Andy. Greetings from Poland

MAc
sp9mrn

MAc wrote:.
I have only 1 piece of
IC, it's surface mount, and I'm afraid, that if I use it in my test
board I will have nothing to use in my receiver.

Andy writes:

God how I hate surface mount.... It used to be that I could send
away for a freebee, or buy a chip from Digikey, and get normal,
civilized, 1/10 lead spacing pins that I could use in a socket, or
use the pins as tie point for "dead bug".....
I could build a circuit up as fast as I could go and the connecting
of the parts together was an insignificant part of the process...

NOW, for the last several years, all freebees I have received have
been surface mount. I have to work under a magnifying glass, with
a special thingy for my soldering iron, and use small pieces of copper
wire strand that I get out of lamp cord to expand the chip to the point
where I can actually attach resistors and capacitors.... it takes more
time
to expand the surface mount than to build the rest of the circuit... As
a
result, I lose enthusiasm a lot......

I have a few things that I have done with surface mount, but I long
for the good old days...... Fortunately, I have about 30 years of
accumulated freebees that I haven't gotten around to using, and can
usually come up with a way to build something.... However, the miracle
chips (as I call them) that Analog Dev, and others, are coming out with
are just too damn much trouble for me.......


If anyone here has some SIMPLE solutions for the surface mount thing,
that does NOT include making a custom PC board, I'd like to learn
about them.....

Andy in Eureka, Texas

AndyS wrote:

If anyone here has some SIMPLE solutions for the surface mount thing,
that does NOT include making a custom PC board, I'd like to learn
about them.....

Take a look at Surfboards, stocked by Digi-Key:

http://dkc3.digikey.com/PDF/T062/1634.pdf

Dana K6JQ

I never tried to use this chip as an SSB detector, but I did design an AM
sync detector a couple of years back. I remember that I had to limit the
input level to around 30uV when used in the fashion, but it wasn't bad for
that purpose.

Pete

"MAc" wrote in message
...
AndyS wrote:
A Quadrature detector is normally used only for FM demodulation.

Yes.

but (from Analog Devices):
"...Applications of the AD607 include narrowband systems with a high first
IF (21.4 MHz to 300 MHz) and a second IF at 10.7 MHz, 455 kHz, or 450 kHz.
These include Dual Conversion IS136, GSM, TETRA, and MSAT Receivers; and
Single or Dual Conversion VHF and HF AM, SSB, CW, or QPSK Receivers... "

But :-) I did not find any SSB application :-( So I need an example.



Just my two cents worth.... If anyone disagrees, I'd be happy to
learn from them where my explanation is wrong..... but I warn you,
it ain't far wrong.... cause it worked for me for many many years
in designing receivers for both commercial and military products
...:)))))


Andy Thanks for your cents, rather dollars.

PS there is internal quadrature pll in ad607.

MAc