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Help! - circuit compared two RF freqs & triggers when same

gmcjetpilot

Mar 27, 2010
13
Joined
Mar 27, 2010
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13
Help! - circuit compared two RF freqs & triggers when same

The idea is compare a FIXED RF signal (any where from 455Khz to 12 Mhz at least, more range the better) with a sweeping Frequency (RF signal of fixed voltage). The idea is when they are the same, it triggers a pulse to the Z intensity input of the scope.

I NEED HELP with the comparator and trigger. I have zero idea and hoping a few IC's will do it.

theplan.jpg
 

Resqueline

Jul 31, 2009
2,848
Joined
Jul 31, 2009
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2,848
Did you try to Google it? Here are some related results:
http://www.freepatentsonline.com/6563346.html
http://www.freepatentsonline.com/6642747.html
http://www.freepatentsonline.com/6834093.html
http://www.newcircuits.com/circuit.php?id=msr006
Maybe the MC12040 can be used more or less directly?
The comparator action is in principle an "ordinary" frequency demodulator, so a PLL or a quadrature demodulator might be used as the first part, then just a DC voltage window comparator.
Beware of any delay in the comparator action causing a shift in the center indication, due to the sweep speed.
 

gmcjetpilot

Mar 27, 2010
13
Joined
Mar 27, 2010
Messages
13
Did you try to Google it? Here are some related results:
http://www.freepatentsonline.com/6563346.html
http://www.freepatentsonline.com/6642747.html
http://www.freepatentsonline.com/6834093.html
http://www.newcircuits.com/circuit.php?id=msr006
Maybe the MC12040 can be used more or less directly?
The comparator action is in principle an "ordinary" frequency demodulator, so a PLL or a quadrature demodulator might be used as the first part, then just a DC voltage window comparator.
Beware of any delay in the comparator action causing a shift in the center indication, due to the sweep speed.

That is GOOD! Thanks George
 
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