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#1
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Quasi Synchronous??
Hi guys!
I saw this term mentioned in the specs of a radio. What does it mean exactly? That if you hope and listen long enough you can convince yourself it's synchronous? Lucky |
#2
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Lucky wrote: Hi guys! I saw this term mentioned in the specs of a radio. What does it mean exactly? That if you hope and listen long enough you can convince yourself it's synchronous? Which radio? dxAce Michigan USA |
#3
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Lucky wrote:
Hi guys! I saw this term mentioned in the specs of a radio. What does it mean exactly? That if you hope and listen long enough you can convince yourself it's synchronous? Lucky Which radio. The term could mean a variety of things, but if you want a specific answer, please indicate which radio and provide a link to the use of the ter,. Then, somone may be able to provide the correct (exact) answer. craigm |
#4
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Which radio...haven't heard that term.
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#5
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Quasi synchronous detection is a non-PLL type of sync detection.......like
the type that was used in the Drake R7 receiver. Basically, it consists of using a mixer to demodulate the AM signal in this way: the I.F. signal is split into two paths. The unprocessed I.F. signal (one of the paths) is applied to the RF port of a mixer, while the other path is squared up through a limiting amplifier and applied to the LO port of this same mixer. The demodulated audio is taken from the I.F. port (output port in this case) of the mixer. I did a similar design a couple of years ago, using a Philips SA637 Digital FM Receiver chip. Philips discontinued that device so I went with the AD607 for my subsequent design. I hope this helps. Pete "John S." wrote in message ups.com... Which radio...haven't heard that term. |
#6
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I believe that Kiwa detector that went on eBay recently was of this design.
"John S." wrote in message ups.com... Which radio...haven't heard that term. |
#7
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Pete KE9OA wrote: Quasi synchronous detection is a non-PLL type of sync detection.......like the type that was used in the Drake R7 receiver. Basically, it consists of using a mixer to demodulate the AM signal in this way: the I.F. signal is split into two paths. The unprocessed I.F. signal (one of the paths) is applied to the RF port of a mixer, while the other path is squared up through a limiting amplifier and applied to the LO port of this same mixer. The demodulated audio is taken from the I.F. port (output port in this case) of the mixer. I did a similar design a couple of years ago, using a Philips SA637 Digital FM Receiver chip. Philips discontinued that device so I went with the AD607 for my subsequent design. I hope this helps. Ahhhhh yes, in the Drake R7 it's known as "synchro-phase" detection. dxAce Michigan USA |
#8
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"Pete KE9OA" wrote in message ... I had one of those. It did have quite a bit of RF gain, but the I.F. strip did not have the gain that the Plessey SL6700 that is used in the HF-150 does. They are not the same receiver, performance wise. If you can find one in the 125 dollar range, it isn't a bad deal. Pete "Lucky" wrote in message ... "John S." wrote in message ups.com... Which radio...haven't heard that term. OK I'm interested in the old Lowe SRX-100 also known as the AKD Target HF3 and now the Nasa Target HF3/p or Nav-fax 200. Check on the very bottom specs under "demodulator: I'm going to buy one. They look cool and seem to have the same Lowe slower rate, faster rate knob. Simple receiver but I seem to like it from what I've read about them. Now this company makes a Nasa Target HF5E that I can only find in Germany. It's supposed to be comparable with the Lowe 150. http://www.pyacht.net/cgi-local/Soft....htm?E+scstore Lucky Hi Pete would you say it's more a portable wise type perfromance? What did you do with yours? Anything decent about it?? Lucky |
#9
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I do have the service manual for the R7 in PDF form. U1102 is the
Synchro-Phase detector chip...........it is indeed an MC1496. Good low distortion component. Pete "dxAce" wrote in message ... Pete KE9OA wrote: Exactly............it was a good sound implementation. I believe that they may have used an MC1496 for that part of the circuit. I doubt that info would be in the supplied owners manual, and I do not have a service manual otherwise I'd try and look it up. dxAce Michigan USA |
#10
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Hi Lucky,
It was ok.................. not a lot of gain in the I.F. system, but it did have enough RF gain. It is probably a matter of preference, but I like my radios to have their gain distribution set up so that the I.F. strip provides most of the system gain. This way, you get a higher amount of headroom in the front end if the gain in that section of the receiver isn't too high. It did work better than any of the portables I have used. I bumped up the gain in the I.F. strip a little bit, and I was relatively happy with it. I ended up trading it off in a combination deal for a Yaesu FRG-100, which I ended up selling along with the optional CW filter and the FM board for 300 dollars. Some older fellow in one of the Carolinas bought it. Pete Hi Pete would you say it's more a portable wise type perfromance? What did you do with yours? Anything decent about it?? Lucky |
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