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inductor coil choke?

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colin886

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Im making a traking device **broken link removed**
i am very bad at making the coil (L1).
I have two parts:a inductor multilayer 0.1uh,conformail coated RF choke 0.10uh.
Whould one of them work insted of L1
thx :?: :!:
 
Just Wind 8 turns of almost any size magnet wire around a Regular diameter Pencil and slide it off of the pencil.

Than to adjust the frequency, Just Stretch or Compress the length of the coil till you can hear it in your reciever.

Stretching it Raises the Frequency. (Less Inductance)
Compressing it Lowers the Frequency. (More Inductance)

This is NOT a complicated coil and It is VERY Easy to do.

Your Real Problem will be to get the LM3909. Its been Discontinued for years.

Gary
 
They Might Work, But you Can't change there Inductance, Should that be Necessary to correct for frequency.

The Trimmer Capacitor does frequency change, but it May Not allow enough adjusment.
 
I don't see how that circuit can oscillate without an emitter resistor or choke. C4 is supposed to provide the positive feedback but can't with the emitter grounded as shown. This is the only one of his many FM transmitter circuits that doesn't have an emitter resistor.
 
Yes Audioguru, I Agree. I Never noticed that missing resistor.
 
He fixed it when he found out that the IC was discontinued:
 

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