22 Nov 2015

10m WSPR TX beacon

Some years ago, I used the following circuit to get on 10m WSPR at low cost.

See https://sites.google.com/site/g3xbmqrp3/hf/wispytx.

Although I also built a simple WSPR RX for 10m, I never got around to combining both the TX and RX into a single unit. Sadly, my stroke got in the way.


Steve McDonald said...

That's a very interesting circuit Roger. It might make a good 630m experimental project, maybe with a low power linear switching FET in the PA.....hhhmm.

Steve VE7SL 73

Steve McDonald said...

....or maybe not. The xtal would be a problem unless a divided down HF xtal is used? I don't think a standalone L-C oscillator would be stable enough.


Roger G3XBM said...

No 14.060 crystals are commonly available and low cost! That is why this circuit was developed! This is probably the most common crystal on the planet. It is the 20m QRP frequency.

Steve McDonald said...

Not 14.060 xtals .... something that could be divided down for a 630m version of your circuit.

Roger G3XBM said...

Sorry Steve, we were at cross-purposes. Although my 630m transverter (see my website) used a 3.2MHz crystal on TX, other frequencies could be used. In WISPY the PA output can be increased further by paralleling more PA devices. I used 4 at one point. Much lower cost than a 2N3866.