Screengrab of 1.8kHz earthmode transmission today

Today I modified my VLF TX so it could send either a 10 wpm or QRSS3 beacon signal. I also went out into the fields with my loop/preamp and a PC with Spectran to receive it. For the first attempt with a PC I went 0.3km away from home where the 4W signal from the earth electrode "antenna" could clearly be received by ear. With Spectran I could read the 10wpm CW signal with 20dB S/N in a 12Hz bandwidth, if my understanding of the Spectran settings is right. There is an audio recording here so you can judge the S/N yourselves. This suggests that with QRSS3 and really screwing the bandwidth down I should be able to do much better. My problem is knowing how to calibrate the soundcard etc and clearly I need a more stable source than my free running twin-tee audio oscillator.

500kHz WSPR - without an antenna!

Well, I'm amazed. This evening I connected my 500kHz transverter straight to the two connections of my sub-9kHz grounded electrodes and TXed WSPR. No attempt was made to match anything on the assumption that the two electrodes system looked not too far from 50 ohms resistive as measured between 1-9kHz.. Pout from the IRF510 is around 5W. What happened?

Three people copied me - M0BMU, G7NKS and M0JXM with reports between -21 and -28dB S/N. The wire to the furtherest ground rod is at most 20m long and most of the way it is 1.5m above ground. Once again, this must be acting as a pretty effective loop mostly within the ground.  Screen grab of the WSPR log attached.

So, if you live on clunchy chalk soils like me then don't worry too much about big antennas, :-)

Grounded electrode antenna on 500kHz

This evening I tried listening on 500kHz WSPR using the 20m spaced grounded electrode pair "antenna" in the back garden (earth rods 20m apart). To my surprise I decoded G3ZJO and G7NKS. Both stations were using just 1-2mW ERP. I'm tempted to try this "antenna" (actually a loop formed in the earth) on TX to see if anyone can decode me on 500kHz.

WSPR with the X80 and 5W

Well, here is a summary of my (intermittent) QRP WSPR beaconing tests since I erected my X80 vertical at lunchtime today:

• Bands tried 80, 40, 30, 20, 17 and 10m (reports received on all bands tried)
• Reports from 25 different stations in 14 countries and 3 continents
• Best DX 6105km on 17m

So, a reasonable test for the antenna and I believe it is working out pretty well so far.

Pasties

As a west countryman from Devon I love pasties. We occasionally make our own, but usually buy Ginsters which are not a bad pasty. For the VERY best pasty, you will be hard pressed to beat those made in the west of England by Ivor Dewdney. Fifty years ago I remember a trip shopping in Plymouth wasn't complete without eating one of these! They are still made the traditional way, by hand. Heck, I could eat one now.

SRC X80 multi-band vertical erected

My SRC X80 multi-band vertical was erected without problems this morning. Fed via about 10m of coax through the house and matched to my FT817 via the Elecraft T1 auto-ATU, it managed a decent match on all bands from 80-10m. Within 2 minutes of tuning it up I'd had two QSOs with 5W QRP CW: HA3FTA on 10m (599) and LA5CB (559) on 12m. So, promising results so far. The next test will be to try WSPR beaconing on the various bands as this is a good check of general performance.

UPDATE 1hr later: Tried WSPR at 5W on 28, 14, 10 and 7MHz and have had decent reports from around Europe on all these bands. I've just got a WSPR report from W8LIW on 18MHz at 6105km. So, it's doing a credible job.

See my webpage about the antenna: http://sites.google.com/site/g3xbmqrp/Home/x80ant

6m WSPR - and tropo?

In between other things tonight I've been running WSPR on 6m. Interestingly I seem to be able to consistently copy G8JNJ 184kms away, presumably by tropo? He's also decoded me once. Don't think it is aircraft reflection as no Doppler evident on the WSPR display. Also managed to see and be seen by EA1FAQ. I use a V2000 triband vertical on 6m.

Twin tee oscillator

A twin-tee audio oscillator is a very useful item to have around the shack. Looking around the net for suitable circuit values yesterday I came across this page by G0XAN http://homepage.ntlworld.com/g0xan/twin-t.htm

I shall be using one this week with my CW keyer to send slow CW (QRSS) on 1.2kHz and 8.97kHz. For very slow CW I'll need a much more stable oscillator probably a crystal and digital divider, although many on the "Dreamers Band" are using a DDS source.

A very young trainee engineer?

This afternoon I had some "help" from a budding radio engineer aged 2.5yrs - my young grandson. We were in the lab mending a toy fire engine (see picture) but he was more interested in twiddling the audio generator and listening to the tones and watching these on the oscilloscope. To see the video go to http://www.youtube.com/watch?v=tRwaT9s6ZHM

Latest NOAA sunspot predictions for cycle 24

The very latest sunspot predictions from NOAA for cycle 24 make rather depressing reading showing a 95% probability of a peak smoothed sunspot number of just 91.8 in June 2013. By this autumn we should see counts in the mid 40s and the following autumn around 75.  10m transatlantic openings should be common again from this autumn, but the low sunspot peak suggests 6m openings will be much less frequent than in recent cycles. So, in my lifetime it is unlikely I'll ever see again the halcyon days of the peak of 1957-9 when conditions were remarkable.