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frequency sampling from RF waves

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darkness.signals

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hi there...
how can i get a frequency sample from RF wave? of course too near by sender(wave generator).
does it work with a PICKUP COIL witch connected to a prescaler unit(sp8704)?
 

The frequency of a wave cannot come alone. It comes with either signal voltage or current. You need a DEVICE connected to an antenna which picks up a sample of wave power, and has terminals on which you can connect a frequency meter, counter, etc. A pickup coil can be such device, but as its diameter is small compared to the wave length, so the signal power to be used would be small, too. A better choice is a half-wave dipole or a directional antenna.

Some frequency counters can measure signal frequency with only a quarter-wave antenna not very far from the transmitting antenna. A power level like -10 dBm is enough for them to measure.
 

thanks...
look my friend...actually i want to detect frequency of a remote control...and this is my plan:
i connect to ends of a dipole to correspond pin on a prescaler unit (sp8704) then to a simple amplifier then to a micro controller!
does it work?

- - - Updated - - -

thanks...
look my friend...actually i want to detect frequency of a remote control...and this is my plan:
i connect to ends of a dipole to correspond pin on a prescaler unit (sp8704) then to a simple amplifier then to a micro controller!
does it work?
 

darkness.signals said:
thanks...
look my friend...actually i want to detect frequency of a remote control...and this is my plan:
i connect to ends of a dipole to correspond pin on a prescaler unit (sp8704) then to a simple amplifier then to a micro controller!
does it work?

- - - Updated - - -

thanks...
look my friend...actually i want to detect frequency of a remote control...and this is my plan:
i connect to ends of a dipole to correspond pin on a prescaler unit (sp8704) then to a simple amplifier then to a micro controller!
does it work?
Click to expand...

Maybe your prescaler connected to a dipole could work. You have to try it. Prescalers usually are connected to a coupled oscillator output, so their RF input power is specified in their data sheet.

I have a pocket counter operating from 10 to 3300 MHz; it can work with a quarter-wave dipole if an antenna connected to a RF signal source is up to one meter away.

If your prescaler does not work, it possibly needs a preamplifier, a better antenna or get it closer to a source antenna. You can also use a borrowed spectrum analyzer, or, a receiver tunable to the expected frequency. Using a laboratory instrument is easier than building a special device if you only need once to check the frequency.
 
what's the "prescaler ic" of your pocket counter?

- - - Updated - - -

what's the "prescaler ic" of your pocket counter?
 

I am sorry, I have no access to such details. The pocket counter is Optoelectronics CUB Mini Counter and has all electronics sealed in a block. Its cost is ~ $120.- building a special device would cost you more. I would advise you to try e-bay where similar counters can be available for a low cost, and ready to use.
 

Apart from the signal pick-up problem (should basically work, I think) you might face the problem that the transmitted RF burst of your remote control is too short related to the frequency counter gate time.
 

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