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quadrature detector & SSB
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 |
#2
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quadrature detector & SSB
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 |
#3
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quadrature detector & SSB
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 |
#4
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quadrature detector & SSB
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 |
#5
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quadrature detector & SSB
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 |
#6
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quadrature detector & SSB
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 |
#7
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quadrature detector & SSB
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 |
#8
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quadrature detector & SSB
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 |
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