20 Oct 2011

2 countries worked with the 28MHz XBM10-2

Well, off to a good start today with a couple of QSOs with the 2 transistor XBM10-2 60mW 10m CW transceiver. Much to my surprise I got 439 from IT9QAU/QRP at 1547z today.  Distance was 1414km.

Then 599 (with chirp) from M0DRK, who is in the same village as me. So 2 DXCC countries worked already.  On receive, the oscillator will not always start in the latest circuit version in which I've reduced the component count by a further 2 parts (just 11 parts plus crystal and earpiece now).  Still, a very promising start for something so ultra-simple.

UPDATE 1850z 20.11.10: To get the oscillator to always start on RX, to get TX spot-on 28.060 with the right offset for RX I had to revert to the earlier design and put 2 parts back. The revised schematic is shown here. This IS such fun.


Anonymous said...


That's good going for 60mW From a simple transceiver.
You should get across the pond when conditions are good.


Roger said...

In the end to get the right offset between RX and TX and the TX spot-on 28.06MHz I've had to revert to yesterday's design with a couple of value changes. Well pleased with the results though.

gj7rwt said...

Simpler than a pixie with better results. Well done Roger!

LY3LP said...

Awesome rig, Roger!

73 Klemensas