FM CRYSTAL TRANSMITTER

[rbaybayan]

I did design a crystal FM transmitter using electret microphone at
3 Volts supply. I need help how to increase further the transmitted voice
signal. It is too soft on the receiver end.

 

[Roff]

Received amplitude is proportional to frequency deviation. If you are trying to directly modulate a crystal oscillator, you will never get enough deviation for reasonable received amplitude. Maybe **broken link removed** would be useful to you.

 

[rbaybayan]

Thanks for your input. The link does not help much as I would like to
maintain the design with some minor modification. Any idea's to make
this things work?

Regards,

Ruel

 

[motion]

Try reducing the "Q" of the crystal to allow it to have a wider frequency swing. Depending on the oscillator circuit used, you may connect a resistor in series or parallel with the crystal.

However, the resistance value chosen might inhibit the circuit from oscillation so start with say a 1megaohm for a parallel connection or 100 ohm for series connection and adjust accordingly.

 

[seeker]

Hi rbaybayan

Thanks for your input. The link does not help much as I would like to
maintain the design with some minor modification. Any idea's to make
this things work?

If you could show your design we may be able to help more.

Thanks.....Tony