I've modified many 20a's using the directions on my web page. The key is the varactor. I would guess that the one you have doesn't give a 400 pfd variation in capacitance.with an 8n 0r 9 volt variation. What is the varactor diode that you are using? I have used the NTE618 and it has a capacitance range of 20pfd at 8 volts and 420pfd at 1.2 volts. Also acceptable is a MVAM108 or MVAM109 Let me know what you are using. Send me your email address to
kc0wox@... and I'll get back to you by email.
Leonard
kc0wox
