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.

Nuclear Fusion breakthrough?

Some recent research may have helped the dream of unlimited and pollution-free energy from nuclear fusion become a big step closer. Scientists in the USA have demonstrated that containment of atoms for fusion using laser beams is far less problematic than first thought. Unlike current nuclear fission, nuclear fusion reactions create no radioactive waste materials. Potentially nuclear fusion reactors, if created on a commercial scale, could dramatically help supply clean energy the world so badly needs. See http://news.bbc.co.uk/1/hi/sci/tech/8485669.stm

Super-efficient VHF antenna?

See http://www.nist.gov/public_affairs/techbeat/tb2010_0126.htm#antenna

"The National Institute of Standards and Technology (NIST) and partners from industry and academia have designed and tested experimental antennas that are highly efficient and yet a fraction of the size of standard antenna systems with comparable properties. .....NIST engineers are working with scientists from the University of Arizona (Tucson) and Boeing Research & Technology (Seattle, Wash.) to design antennas incorporating metamaterials—materials engineered with novel, often microscopic, structures to produce unusual properties. The new antennas radiate as much as 95 percent of an input radio signal and yet defy normal design parameters."

Mosquito single IRF510 transceiver

EA3GHS and EA3FXF have produced a single IRF510 FET based version of his Mosquito transceiver using a PC as the back end of a software defined radio (SDR). In essence, the FET is used as a regenerative or direct conversion receiver - I think the two are indestinguishable in a single stage RX - with audio coupled to the sound card via a mains transformer which steps up the impedance. The IRF510 is capable of up to about 7W in this application. Coupled with an SDR back-end and this is SOME simple transceiver, especially if the crystal is VXOed.