Fix for FM syntheized tuner slightly off channel

[xavirom]

I set up a "functional overview of the lm7001" :



Just to get an understanding of the working.


I manually tuned to an FM stations specified frequency (here 99.2Mhz)
stereo reception was ok.


Then i adjusted the discriminator coil (LA1265) to minimum/0-volt at testpoint with voltmeter.


eh voila...the auto-tune function now stops at the stations specified frequency.


However..then the audio quality is again distorted as not being in center tune.

Hi.
I have the same problem with a pioneer F205 tuner with the same set of ICs, but I did not have the same luck, I never achieved zero volt at the test points by moving the adjusting screw from end to end, to achieve this I had to add capacity in parallel outside the discriminator coil. Only then do I get the automatic tuning to work, but the distortion is terrible, it only disappears when the voltage at the test points is far from zero volts, any ideas?