Simple QRP projects, 10m, 8m, 6m, 4m, FT8, 160m, WSPR, LF/MF, sub-9kHz, nanowaves and other random stuff, some not related to amateur radio.
1 Feb 2010
XBM80-2 heard at 430kms
This evening I tried listening for my 60mW CW signal from my XBM80-2 80m micro-transceiver on the on-line SDR at Twente in Holland. The signal was clearly audible at RST529 when I keyed the transmitter slowly! Distance is 430kms (267miles).
I need to improve the RX selectivity as AM breakthrough is a problem at times. I will try replacing the choke with a tuned circuit as AA1TJ did and see if this helps. The circuit is so simple but for local QSOs perfectly fine as a full transceiver. AA1TJ always manages DX with his versions - good ears and patience!
Tony, I would expect the oscillator to "chirp" if the VXO range with a ceramic oscillator was reasonably large. For such a simple circuit it is probably better to stick with crystal control. However, try it and see what happens.
Amazing, Roger. I think I'm going to have to put all my other projects on hold and build one of these.
ReplyDeleteI need to improve the RX selectivity as AM breakthrough is a problem at times. I will try replacing the choke with a tuned circuit as AA1TJ did and see if this helps. The circuit is so simple but for local QSOs perfectly fine as a full transceiver. AA1TJ always manages DX with his versions - good ears and patience!
ReplyDeleteIs 'nt that twice 430kms?
ReplyDeleteRoger
ReplyDeleteIf I use a ceramic resonator instead of a crytal will the circuit produce the same output power with a wider frequency shift?
73 Tony G4LLW
Tony, I would expect the oscillator to "chirp" if the VXO range with a ceramic oscillator was reasonably large. For such a simple circuit it is probably better to stick with crystal control. However, try it and see what happens.
ReplyDelete