Jazz at Ronnie Scotts in London

Tim Lapthorn at Ronnie Scotts

Our son Tim shown here on the piano at one of his many recent appearances at the world famous Ronnie Scotts jazz club in central London. His new album "Intentions" is due out later this year and will feature many of his new original compositions. See www.timlapthorn.com .

Latest NASA sunspot predictions

From the http://solarscience.msfc.nasa.gov/SunspotCycle.shtml website dated March 1st 2011:

"Current prediction for the next sunspot cycle maximum gives a smoothed sunspot number maximum of about 58 in July of 2013. We are currently over two years into Cycle 24. The predicted size would make this the smallest sunspot cycle in nearly 200 years."

Gloomy reading? Very recent solar levels in the last week or so may be just a blip, but something tells me we could all be in for a very big, and pleasant, surprise should activity continue to build as rapidly as it has recently. The sun is still full of surprises and no-one predicted the 2 year quiet sun we just had at the end of cycle 23.

I still find http://www.solen.info/solar/ the best page for up to date information on current solar activity.

Doppler shift on 10m WSPR Transequatorial

This afternoon, before working some QRP DX on 10m and 12m SSB I had my WSPR system running and spotted FR1GZ (Reunion Is) several times at good levels. What was interesting was the Doppler shift on his signal which was up to -3Hz at times. I guess the propagation is trans-equatorial spread-F and what I'm observing are moving F-layers on the path between us.

Welcome back 10m "big time"

Today 10m sounded like the good old days with good strong contest signals from the USA and Canada as well as South America and Africa earlier in the day. I managed to work several stations in Texas, Alabama, Tennessee and Louisiana when running QRP SSB to the Homebase10 wire halo. This is the first time in around 5 years that I've heard the band like this. Welcome back good old 10m!

A busy VLF amateur band (8-9kHz)

DK7FC's 8.97kHz grabber showing 4 stations active!

This screen shot from DK7FC's grabber shows just how busy this band is now becoming and how much progress has been made in the last 12 months. Visible in the grab taken March 6th 2001 are DJ8WX, OE3GHB, DK7FC (local testing) and DF6NM. Only a year ago people dismissed experiments at sub-9kHz as dreaming whereas today stations are regularly getting reports from anything from a few km to nearly 3000km for the better equipped stations.

This is REAL ham radio at the frontiers folks - put your cheque books away, forget those black boxes and join the fun on the Dreamer's Band.

28MHz simple WSPR transceiver idea

Whilst playing with VXOs for my 10m DSB transceiver I realised that a cheap 14.060MHz crystal (available widely for about £1-2 each) would make a nice LO source for a 28MHz direct conversion WSPR transceiver. Doubled, the output is easily pulled to 28.1246MHz, the WSPR frequency. The PA does not have to be linear, so all that is needed apart from an oscillator/doubler is a single balanced mixer followed by a small PA. With the DSB approach, half the power is wasted and there would be an audio image 3kHz away on RX. However, the audio stages could be filtered to allow just 1.4-1.6kHz through. The whole transceiver could be extremely simple and stand-alone. I must build one.

ARRL SSB DX contest

Although there are US stations coming through on 15m, I've not yet heard any on 10m. Signals from LU1UM on 10m but nothing yet from North America. Sunspot count is high but conditions on 10m do not sound that good. Just worked N2PP on 15m SSB when using 10W to my 28MHz halo!

VLF Dreamer's Band video

For those interested, I've made a short video showing my current VLF receiving set-up for 8.7-9.1kHz (antenna, matching, preamp, PC) used in the recent VLF reception tests in which G3XIZ has been copied twice now (45km), DJ8WX all of yesterday (645km) and DK7FC/P twice (629km). I am not claiming it to be fully optimised, but it certainly works.

What I like is that the wire antenna and the preamp cost a few pounds, the software is free (thanks Wolf) and the results mind blowing. In the near future I will try replacing the loop and preamp with a small E-field probe.

This is the link http://www.youtube.com/watch?v=UxEAhqPFBFE

Also, G3XIZ was copied again on 9.0909kHz VLF at 45km. He was also copied by a few other UK stations including G3ZJO and M0BMU.

DJ8WX received on 8.970022kHz

DJ8WX on 8.970022kHz VLF (645km)

Overnight tonight I received a new station on VLF:  Uwe DJ8WX who is 645km east of me. Uwe was a solid signal here in JO02dg in the early hours on 8.970022kHz. His signal level dropped off during the night somewhat but he was still visible at 0500z. Spectrum Lab settings were as for the G3XIZ reception the previous night with the FFT bandwidth set to 423uHz. This is the 4th ham station now copied at VLF in 4 unique locator squares and 2 countries.

G3XIZ copied on VLF (at last)

G3XIZ received on VLF

Overnight, Chris G3XIZ was transmitting a test carrier on 9.0909kHz using 80W into his normal inverted-L antenna used on 136 and 500kHz matched with a large VLF loading coil. Using Spectrum Lab software and 423uHz bandwidth FFT settings I managed to get quite good copy of his signal using my 80 sq metre loop and small FET preamp. Between 0300-0600 his signal was around 10dB S/N in this bandwidth. Distance between us is around 45km. Later I got this email from Chris:

"You've re-awakened my enthusiasm which I must confess was fading. You are absolutely correct -  I checked the transmitter about 02.30 and found that the aerial current had dropped off, maybe due to a change in loading coil inductance with temperature. I increased the drive and brought it back to the initial level of 0.18 A. You and I seem to be at the extreme range with my current set up and if the new loading coil is more efficient we must try the experiment again. I am pleased that the OCXO seems to stable enough for our purposes. Once I've cured my off air standard of losing 'lock' I'll use that as the frequency source. My TX input power was 120 watts giving an output RF of about 80 watts. This should automatically be increased with the better loading coil."

UPDATE: Paul Nicholson in Todmorden Yorks has confirmed he received Chris at a distance of 218km, a new record for a UK VLF ham station.