Скачать или смотреть SM7NWJ Hamradio direct conversion phasing receiver for cw on the 20-meter band.

Pictures showing the insides of the boxes can be viewed at:
http://www.flickr.com/photos/36624663...

Video showing me tuning around the cw (morse code) portion of the 20m amateurradio band (14.0-14.1 MHz) with my homebuilt version of a phasing type direct conversion receiver.

2012-04-07: Since recording this clip the VFO is now modified to only cover 14000-14055kHz. Before making this mod the tuning was a little too sensitive. It was difficult to tune stations correctly. Now the tuning is definetly smother. It could of course be improved further with a better mechanism, but this is as far I'm taking it. Instead I would like to build a DDS (or combined DDS-PLL) VFO for the receiver.

It's a test setup without a bandpassfilter on the RF input of the receiver. The antenna is an active loop covering 0-30 MHz. Despite the broadband HF input there is no indication of out-of-band signals getting through. A bit surprising and somewhat amazing.

The output of the receiver is connected to a 6.5 inch diameter loudspeaker.