Quote:
Originally Posted by Jeg
Hi friend
Looks like something is wrong, but wait for Franco to tell his opinion as he is very experienced on this. 
(try connecting your voltmeter at the output of your sensor. When you touch the antenna, does the output signal drops?) |
Yes, otherwise it could mean that there is a self oscillation. By touching the antenna a part of the signal on the base of TR2 (the mixer) is absorbed by the body and therefore the signal amplified by the sensor stage decreases slightly.