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Modulating an audio signal if you already have a carrier wave.

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Hi all

Asking about a fairly unknown (to me) field of electronics here...RADIO.
All I want to know is how I can use my Tektronix sine-wave generator to modulate an audio signal for short distance (couple of meters) FM transmission.

The generator can generate frequencies of 1Mhz to 200Mhz, but I would like to use a standard FM radio for de-modulation. 85-108 Mhz

I just got sick and tired of these crappy two-transistor fm transmitters with the electret mics and trimmer capacitors, and thought better quality could be obtained when a pure sinusoidal carrier wave is used.

schematics are welcome :)

Thank you.

Hanno Bisschoff
South Africa
 
Does your generator have an FM modulator input? - I rather doubt it.

The crappy little bugs are pure sinewave as well, there wouldn't be any advantage trying to use your generator.
 
Okay, sorry for referring to them as "crappy" I didn't mean to be rude.
The major issue with these bugs is finding the right broadcasting frequency with either the bug's trimmer cap or the radio's tuning knob. This is where the advantage of the generator comes in. Because it displays the frequency digitally on a screen, so now the transmission frequency can be exactly determined, and the radio can be tuned to that frequency.

I also kind of want to learn how FM works.

thank you.
 
You say that you have a "Tektronix sine wave generator", what is the model number?

Without details of the generator, it is impossible to tell how to modulate it.

JimB
 
OK then, the quick answer is that you don't.
There is no provision to frequency modulate that equipment.

However, if you have a sense of adventure you could try adding a simple varicap diode modulator to the L143/C100A tuned circuit for the 100 to 250Mhz oscillator.
Do you have the manual?

JimB
 
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