UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Home brew converter to listen to Satellites, plus capture of Voyager TX by NASA

G6Tanuki · 4th Dec 2017, 4:12 pm

Must admit, for VHF converters I always liked the double-balanced-diode-mixer approach [MD108/SBL1 etc] - their strong-signal-handling capacity being a particular feature, important if you've got any powerful two-way or broadcast-transmitters in the area.

One of these with a low-gain RF amp [grounded-grid/gate/emitter stage according to taste?] coupled with loads of local oscillator drive to ensure the mixer really *is* being switched by what amounts to a square-wave, will get you going.

I did once build a VHF converter with push-pull 6J6 double-triodes as RF amp and mixer, as the only way to hear 2-Metre signals when I was line-of-sight to the Blaenplwyf VHF Band-II transmitter and its hundreds of Kilowatts.....

4th Dec 2017, 4:12 pm	#35
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,005	Re: Home brew converter to listen to Satellites, plus capture of Voyager TX by NASA Must admit, for VHF converters I always liked the double-balanced-diode-mixer approach [MD108/SBL1 etc] - their strong-signal-handling capacity being a particular feature, important if you've got any powerful two-way or broadcast-transmitters in the area. One of these with a low-gain RF amp [grounded-grid/gate/emitter stage according to taste?] coupled with loads of local oscillator drive to ensure the mixer really is being switched by what amounts to a square-wave, will get you going. I did once build a VHF converter with push-pull 6J6 double-triodes as RF amp and mixer, as the only way to hear 2-Metre signals when I was line-of-sight to the Blaenplwyf VHF Band-II transmitter and its hundreds of Kilowatts.....