20 Sep 2012

472/500kHz transverter FINISHED

Today I completed the rev E version of my 10W transverter. In the end I reverted to a double balanced mixer and this immediately solved my issues with mixer stability that I had with the transistor mixer design. Air testing this evening, I am getting plenty of reports but a slight drive is noticable in the reports, probably as I am using a small plastic box and the PA heatsink warming is causing the 3.2MHz crystal to move about 1Hz during the WSPR TX cycle. It really needs a bit bigger metal box, but it will do.

The lastest transverter schematic (there may be value errors)
WSPR reports 20.9.12 with the above transverter and 6m long antenna
The desktop 472/500kHz station, ATU (don't laugh!) and antenna current meter

1 comment:

Bob G3WKW said...

Looks interesting, I might be tempted. If you were going to publish perhaps worth having a mod for those who might want to put 5 watts in from an FT897 or similar. Probably use 10x560 ohms for the input load.