Don't think so. This is FM, so the deviation and modulation bandwidth will increase by 9 times, but the rate of deviation will be the same. The carrier will transition from one instantaneous frequency to the next at the original audio rate.

ak

Do you have any graphics of waveform and frequency to show what you said, I just want to know how come if a signal already mixed and multiple 9 times, how can it not through the dividing procedure to back to the original frequency of signal?

 

Do you have any graphics of waveform and frequency to show what you said, I just want to know how come if a signal already mixed and multiple 9 times, how can it not through the dividing procedure to back to the original frequency of signal?

It can. But that is not what I was responding to. Posts #12 and #13 both say that when the modulated carrier is multiplied, the *modulating signal (or audio)* is multiplied. It is not. The deviation caused by the modulating signal is multiplied up. In other words, the modulation is multiplied, but the modulating signal is not.

Example: If I modulate a 10 MHz carrier with a 5 kHz audio signal, the 10 MHz carrier now deviates at a 5 kHz rate. How far it deviates is set by the modulator circuitry; it can be narrow band, wide band, or something in between. For this example, we will set the modulator so that peak audio deviates the carrier by 100 kHz. So the carrier is swinging back and forth between 9.9 MHz and 10.1 MHz at a 5 kHz rate.

If we multiply the carrier up by a factor of 10, it now swings back and forth between 99 MHz and 101 MHz, but it still is swinging back and forth at a 5 kHz rate. Dividing this signal will return it to its original modulated 10 MHz state, but simple division will not recover the baseband audio.

ak

 

when generating fm through frequency multipliers, the deviation is increased, not the audio frequency of the modulation. a 1000 hz tone modulated signal multiplied any number of times is still 1000 hz, only the deviation is increased.

 

There is a frequency multiplier after the oscilltor. The transmitted frequency will be 96.3 Mhz.

Where is the frequency multiplier in the circuit?

 

There's some noise but the audio can be heard.

Have you measure the transmitter frequency and receive frequency and audio frequency?

 

Where is the frequency multiplier in the circuit?

Those three inverters in parallel just prior to the antenna and its capacitor have very fast rise and fall times, as a result, the 10.7 MHz square wave will be rich in odd harmonics.

 

Those three inverters in parallel just prior to the antenna and its capacitor have very fast rise and fall times, as a result, the 10.7 MHz square wave will be rich in odd harmonics.

I never treat or use the odd harmonics as the main frequency.

 

I recall, from back when I read electronic component catalogs even though I didn't understand anything in them, "third overtone crystals".

ak