From: Steven Weber To: Low Power Amateur Radio Discussion Date: Monday, August 12, 2002 13:56 PM Subject: Re: QRM >with the all SMD kit I build last year. Is this a problem with me >building the kit, or an anoying 'feature'. > Hubert, The AM QRM is an anoying feature, common to many DC recievers :-( The xtal in the front end goes a long way to reduce this problem, but it can't totally eliminate it in some cases. We have some trouble with Radio Canada here in Northern New England. Operating the rig with a battery instead of an AC mains supply usually helps alot. Adding an audio filter also helps by cutting down the BW and peaking up the signals you want to hear. You can also try going to a "double diode" (two diodes in series) instead of the single pair of diodes in the T/R switch. Finally, attenuating the input to the SA612 can help a lot too. Try a 1 K resistor across D1 and D2. 72, Steve, KD1JV "Melt Solder" White Mountains of New Hampshire