18 Jan 2011

1mW DXing on 40m

Today I reduced the power from my 40m WSPR beacon TX from 10mW down to just 1mW. The FT817 is run at minimum power setting (1W) then via a 20dB attenuator within a few cm of the antenna connector and then into a 10dB stepped attenuator. My antenna is the 5m coax feeder (inner and outer strapped together) up to my 10m halo and tuned via the Elecraft T1 auto-ATU. The first report received at 1436 today was from DC4FS at 523km (-28dB S/N).

5 comments:

Paul - PC4T said...

Hello Roger, congrats, that is a very good result. 73 Paul

Roger G3XBM said...

This is certainly fun Paul. At 10mW I was getting quite a lot of reports, so I decided to make things a bit harder!

TiƩgui said...

Of course Roger ! That is for what the WSPR is intended for. I'm just fed up of people using WSPR with 36 or 40 dBm...

Apparently you have been the only one until today who really dedicated WSPR for what is it for.

You should try 80 m, it's really good now on winter. With 1 mW CW beacon I was copied in Paris, the beacon beeing in Bordeaux.

73, from Thierry.

LY2SS said...

Even better! Because you were radiating 0,5mW since ft817's minimal power is 0,5W.

BEST 73! Zilvinas

PE4BAS, Bas said...

Great achievement, not only for you but also for the receiving station.
It's not easy to pick out such signals on a crowded 40m band. You need a very robust receiver. Although WSPR does filter a lot. 73, Bas