Back on 500kHz tonight

Having been playing around with the XBM80-2 80m micro transceiver for a couple of days, I've not been on 500kHz for a bit. However, I am back again tonight with the 1mW ERP WSPR beacon. Reports from LA3EQ and GM4SLV amongst others received so far.

Prosperity without Growth?

Prosperity without Growth? - The transition to a sustainable economy is a freely downloadable publication from the UK's Sustainable Development Commission. The report calls on world leaders to adopt a 12-step plan to make the transitionto a fair, sustainable, low-carbon economy.

Improvements to the XBM80-2 80m QRP transceiver

A few small value optimisations have improved the XBM80-2 transceiver. I've optimised the collector circuit values and this has resulted in 120mW output (was 60mW) from a 12V supply. The sensitivity is a little higher, the backwave level is lower, the amount of AM breakthrough from medium wave broadcasters is lower. At 4pm I was hearing DR2010O in the Ruhr area of Germany working all over Europe and could copy almost all the stations that he was working but I failed to break the pileup with 120mW. I'm beginning to think this little transceiver could be really useful. There is no reason why it should not work well on any band up to 28MHz (with less output) with a fundamental crystal. I'm wondering how it will perform on 50MHz with the collector tuned to x2 crystal?

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).

Another XBM80-2 QSO tonight

This evening I worked G6ALB 3kms away on the XBM80-2 60mW ultra-simple 80m transceiver getting a 599 report. Andrew was copied at 599 when he was using his 300mW TR6C4 simple valve transceiver which has a regen RX. Andrew also sent test transmissions using his signal generator and I was able to copy his signal when he was running 3mW output. So, the conclusion is, as AA1TJ has already proven, the design is quite a useful one and VERY simple.

Good 500kHz DX overnight with 1mW ERP

For the first time in more than a week I ran the WSPR beacon through the night. Best DX reports were from GM4SLV, GM0UDL and Lubos OK2BVG at 1232kms. Lubos sent me this picture of his fine shack. Notice the lovely LF/MF loading coil on the left hand side and the LF receiving loop in the corner. Lubos has a very nice collection of equipment. He has now managed to receive me on several different occasions on 500kHz.

More new ones on 500kHz

A new station has reported my 500kHz WSPR signal this evening: ON4BB in JO21 at 294kms. Later, GM0UDL spotted me from up in IO77 square at 659kms, bringing the total unique WSPR reports up to 76.

AA1TJ's success with the XBM80-2

Mike Rainey AA1TJ has built his version of the XBM80-2, but LESS the audio stage, using instead his 600 ohm magnetic headphones via a transformer, and has managed some QSOs well over 100 miles. He changed the emitter resistor to 15k to reduce the signal radiated on key-up (backwave) as well as made a link coupled bandpass filter output/input circuit. This would reduce the amount of AM breakthrough usefully.

76th unique signal report on 500kHz with 1mW (or less) QRP

This evening, I was WSPR decoded by a new station in the Netherlands PI4Z in JO11wm at 260kms. This brings the total number of stations who have sent me reports on the band to 76 now (72 via the WSPR database, 2 emailed WSPR reports and 2 CW stations) in a total of 10 countries. Best DX report still 1232kms.

CQ-PA article on 500kHz

The Dutch magazine CQ-PA has quite a large article on 500kHz operation this month. I was very pleased to see my little IRF510 based transverter circuit and my small vertical antenna were shown. Amateurs in the Netherlands have recently been granted access to this band.