27 Oct 2011

XBM10-2 Micro-transceiver boxed

This afternoon I rebuilt the XBM10-2 28MHz micro-transceiver onto a small piece of copper laminate and put the whole transceiver in a small diecast box. The transceiver still chirps far too much, but it is in a state where more DX contacts will be possible and I can't see an easy way of reducing the chirp without making it more complex. Maybe I should call it the Chirpy-10?  I'm particularly pleased that the TX-RX offset is just perfect for operation on 28.060MHz CW.

I have just realised that by replacing the earpiece with my PC soundcard I can use several SDR packages to allow me to look either side of the QRP calling frequency. This rather defeats the simplicity though!


Bob said...

I guess you could probably add a soundcard chip and make it into a USB dongle controlled direct from HRD or Multipsk. Would be a saleable proposition for simplicity at another level.

Anonymous said...

Hi Roger - does the transistor give more gain than a passive mixer on rx??

Roger said...

Tony - yes the oscillator mixer stage has gain. In fact I'm not quite sure if you should class this stage as a direct conversion or regenerative detector.

Anonymous said...

Roger - Great that youve worked local and some dx on it.

Did you rely on the antenna to filter the signal or did you use some kind of filter inline.

Hope you can get across the pond with it.

Ed de la Rie // PE5ED said...

and what about feeding it some WSPR
To stay in touch with the project, you could build it into a netbook, and use sma for the antenna out, the very thin coax does coher with the whole idea itself. Thus builing the ultimate small and QRP WSPR/JT65/PSK one box solution ever.

grin, pitty PCMCIA is never used in a netbook, otherwise you would have interchangeble units.