use lm567 as synthesizer in fm transmitter

[zereshki]

Hello.
there are many circuits about fm transmitter using various model of pll chips that operate as frequency synthesizer. but there is no one using cheap IC lm567. it's a pll too.isn't it possible to use it as synthesizer for automatic adjust frequency (of course by prescaler) ?

regards

 

[G4BCH]

The LM567 is designed for audio tone detection. To use it in a synthesiser for other frequencies you would need acess to both inputs to the phase detector here one input is from the interal VCO limiting its use to about 500kHz. There are much better chips around for VHF synthesisers that are designed for the job. For about 3 to 4 times the price of the LM567 you can get a complete synthesiser chip

 

[davenn]

agree with G4BCH

if you wanna go all the way with PIC mpu control there's the LMX series eg LMX2306 2800MHz PLL Synth

if you want something more basic the MC145152-P2 is still available, I have used these up to 1.3 GHz with
a prescaler

cheers
Dave