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Quasi Synchronous??



 
 
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  #1  
Old June 1st 05, 05:36 PM
Lucky
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Default 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  
Old June 1st 05, 05:38 PM
dxAce
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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  
Old June 1st 05, 06:28 PM
craigm
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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  
Old June 1st 05, 07:45 PM
John S.
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Which radio...haven't heard that term.

  #5  
Old June 1st 05, 09:29 PM
Pete KE9OA
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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  
Old June 1st 05, 09:30 PM
Pete KE9OA
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Default

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  
Old June 1st 05, 09:33 PM
dxAce
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Posts: n/a
Default



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  
Old June 2nd 05, 05:18 AM
Lucky
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Default


"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  
Old June 2nd 05, 05:21 AM
Pete KE9OA
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Default

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  
Old June 2nd 05, 05:48 AM
Pete KE9OA
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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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