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

[gmcjetpilot]

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.

 

[Resqueline]

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]

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