1 May 2011

325km with 50uW ERP on 137kHz

Well, Henny PA3CPM has just sent me a new screen grab showing my signal at 1041z today on 137.676kHz in QRSS30. This time you can make out some of the CW (visible just below the continuous Loran line) and the periodicity between callsign blocks is visible confirming this is indeed my signal.  Distance is 325km (202 miles) to JO22mb square. This is the first time my 137kHz signal has got into mainland Europe. I am amazed that a really simple beacon on a tiny board into a simple wire loop in the garden can span such distances. Even more amazed that Henny could find it!

30 Apr 2011

Over 100km on 137kHz with 50uW ERP

Just got a screen grab from G3WCB 101km away showing my QRSS30 beacon signal being received at his QTH near Windsor. Mine is the lower trace in which you can see "BM" (part of XBM). It is not strong, but there. I will leave the beacon running with around 50uW ERP during today.

A few hours later G3WCB got me stronger with the XBM very clear on the screen.

Henny van Elst in Holland was also seeing traces at the right frequency, but too weak to positively identify.

29 Apr 2011

QRSS3 beaconing on 137.6748kHz

My QRSS30 (slow CW) LF beacon has just been started up. I'm hoping that QRSS30 will get me reports from a bit further afield.  Any reports and screen grabs would be much appreciated. It will be on for much of the weekend unless I need the antenna for some VLF tests. The message cycle takes about 25 minutes and best results will be with Argo, Spectran or Spectrum Lab software on a PC and FFT bandwidths of around 0.1Hz.

Message:    
XBM in QRSS30, pause, then G3XBM in 10wpm
Freq:           137.6748kHz
ERP:           50uW (antenna 80sq m vertical loop)
Location:    JO02dg, Burwell Cambs

28 Apr 2011

2 transistor transceiver kit

The Four State QRP Group is offering the new "HamCan" transceiver kit for sale at just $30.  It is a 2 transistor crystal-controlled CW transceiver, delivering 0.5-1W TX power with enough sensitivity and selectivity to receive plenty of signals. They claim it is a minimalist yet good performance transceiver. The kit features a high quality PCB, low parts count and fast and easy building. It is claimed to be an excellent kit for first time builders. It has been selected as one of the ARRL Midwest Convention's Buildathon kits. 

More information at http://www.wa0itp.com/hamcan.html .

27 Apr 2011

Mains hum powered beacon

Recent tests with earth electrodes at VLF have got me wondering about a simple QRSS HF/VHF beacon TX powered entirely from the rectified mains hum and other crud coming from a couple of earth rods in the ground.  Not sure of the available power, but I suspect it would be in the 0.1 to 2uW region, maybe more. This may be enough to drive a low voltage QRSS beacon for example. You can buy power harvester ICs these days for this purpose, but with a step-up mains transformer there may be a volt or two available at a few tens of uA and that alone may be enough to drive a keyed oscillator. The ultimate in free power beaconing!

3km DX on 8.97kHz WSPR today

This morning I successfully decoded a VLF earth mode WSPR signal from G6ALB at a distance of 3km. Signal was quite strong, but for some reason the WSPR software refused to decode it (apart from once) despite clocks being reset at each end. This is my best WSPR DX reception on VLF so far. Andrew was running 40W to an earth electrode antenna. I was copying him on an earth electrode antenna although the WSPR signal was stronger later on the 80m square vertical loop in the garden.

In the afternoon I used my wife's laptop and WSPR decoded every time at -16/-17dB S/N, a very decent signal. There is a video showing the VLF WSPR set-up if you want to see it. 

25 Apr 2011

G3XBM is off to Mars

NASA is collecting names to be put on a microchip that'll be on the Mars Science Laboratory rover heading to Mars in autumn 2011. The rover has special CW indentations on its wheels spelling out  JPL (Jet Propulsion Laboratory).

Bicycle portable in Blackpool

David G4AKC has been on his bike and working some excellent DX (like VK/ZL) on SSB and CW on 20m from his bike parked up next to the seaside in Blackpool. He uses and Alinco DX-70 on battery power with a  home made top loaded 3.5m long vertical against a tuned frame, and operating "over the sea water".  He says several QSOs were possible at the 1W level. See http://www.qrz.com/db/g4akc .

22 Apr 2011

28MHz WSPR DX

Just a couple of outings on 10m WSPR this week, but some excellent reports from 5 continents using 5W and the small halo antenna. Interesting to see what must be Doppler shift drift on both the Reunion Is and Australian reports, presumably because of moving F-layer over the equator?

21 Apr 2011

28MHz getting too easy?

For the first time in several weeks I put my WSPR beacon on 10m this morning. Without any effort, the 5W and the halo got reports from the Middle East and Australia. With the solar flux regularly above 100 now, I'm finding that 10m has moved into its "easy" phase when worldwide DX is becoming easy.  Also, with the Es season just days away now, the European activity will be plentiful and WSPR reports from Europe with microwatts certainly probable.