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FM Transmitter

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WG1337

New Member
Hi!
I have a small radio receiver and also a small radio transmitter.
It used to work, but now doesn't but the reason is that it works on 88.5 MHz frequency, but some jerks made a radio station in the same requency, so the radio isn't clear anymore, so I would need to make transmitter at 88 MHz.
Here are 2 circuits: (don't mind the C and L numbers)
**broken link removed**
The first simply shows that if I close and open the switch I could make sound on the radio.
The second shows that if I change a smaller voltage then with a transistor I open a larger voltage that would be like a plug for the audio jack.
But I have seen that these circuit use more then one capacitor, even resistors but why?
Won't this work?
Also I only have few capacitors and it isn't variable, it says that it has 220 uF with 16V. Does farads change if I only use 3V (2x batteries)?
And I hope these two are suitable for making a coil the right size:
f = 1/ (2*Pi*sqrt(L*C))
L = 0.394 * (N*R)^2 / (9R + 10h) (in meters)
 
You could probably just use your transmitter and unwind a loop in your coil to tune to a higer frequency, or else just spance the distance out a little. Experiment with the coil and you might get lucky. Your other circuits aren't useful for any resaonable transmissions.
 
Well now I don't think that will be possible anymore...
But could you please tell me why it won't be a reasonable transmission?
 
All you'll get from those circuits are decaying transient oscillations. I don't think you'll even get any modulation, so it's not ever FM. I don't see any use for those curcuits, other than maybe determining the frequency and Q-factor of the reactive components.
 
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