Hi everyone! I found on a book and also on the internet this interesting diagram of a FM direct conversion radio.
The problem is that it was designed for the FM OIRT, not CCIR. As a direct conversion the oscillator works at half of the frequency tunned as is described. Will I be able to adjust the circuits to tune into 88-108?
How many turns should have each coils?
Initially it is said: 3+3 for L1 and 20 for L2 (9 turns in the case of using a small ferrite)
Refference: FM receivers with PLL
The problem is that it was designed for the FM OIRT, not CCIR. As a direct conversion the oscillator works at half of the frequency tunned as is described. Will I be able to adjust the circuits to tune into 88-108?
How many turns should have each coils?
Initially it is said: 3+3 for L1 and 20 for L2 (9 turns in the case of using a small ferrite)
Refference: FM receivers with PLL
You have to decrease the inductivity of the coils, either with fewer turns or by pulling the windings apart.
I reduced the number of turnes from 9 to 4,25. I tried to tune into stations.. I received some of them but the sound is not so clear as it's written in the book. Also if you want to tune into stations, after selecting one station it is desired to re tune even the input circuit...
Forget this diagram. I will come back to my one fet superreaction receiver. It has a very good sound and the stations don't overlap.
Forget this diagram. I will come back to my one fet superreaction receiver. It has a very good sound and the stations don't overlap.
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