UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - PIN diode band switching yaesu ft-767

Radio Wrangler · 17th Feb 2021, 4:06 am

I'd question the use of varactor diodes tuning a preselector. If you try to receive a weak signal near to strong ones you are likely to find intermodulation distortion a problem. The large signals pump the capacitance of the diodes and hence modulate the tuned frequency of the preselector.

David

17th Feb 2021, 4:06 am	#26
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,876	Re: PIN diode band switching yaesu ft-767 I'd question the use of varactor diodes tuning a preselector. If you try to receive a weak signal near to strong ones you are likely to find intermodulation distortion a problem. The large signals pump the capacitance of the diodes and hence modulate the tuned frequency of the preselector. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done