G3XBM's 500kHz article in May's Practical Wireless

The follow-up article on my 500kHz transverter and WSPR experiments appeared in the May edition of Practical Wireless today. I hope it encourages a few others to give 500kHz a go, especially as my approach is a simple and easy one.

DF6NM and DK7FC active on 8.97kHz today

Not one, but 2 stations were active on 8.97kHz today in DFCW mode. Part of DK7FC's transmission was copied at 902kms away in Warsaw and DF6NM, running a much smaller station and antenna, was copied 21kms away. A first QSO on the 33kms band cannot be too far away now!

4th Amateur VLF test transmission on 8.97kHz this weekend

Stefan DK7FC is planning to transmit again on 8.97 kHz VLF if the wind is able to support his kite antenna. The tests start Saturday April 3rd, at around 1000 UTC. The mode used will be DFCW-600 (dual frequency very slow CW). Several stations across Europe will be listening some using tiny E-field probe antennas.

Temporarily QRT - shack becomes grandson's bedroom!

It had to happen sooner or later: our elder grandson, now 2.5yrs old, is staying with us a couple of times in the next few weeks as his mum and dad pack to move flat. Tonight he moved from the usual travel cot to a real bed for the first time .....in my radio shack. So, I shall be unable to operate evenings for a while so no 500kHz WSPR I'm afraid. Daytime operation may be possible, but apart from 10m WSPR I doubt I'll be able to do any serious operating. In the meantime he is fast asleep and looking very cosy.

500kHz WSPR - fewer stations around now

500kHz WSPR has gone rather quiet of late with fewer stations on most evenings. So far only M0BMU has reported me tonight, despite my report being pretty strong. A new 500kHz WSPR receiving station this evening is OY6FRA and it would be great if he could hear me 1164kms to the north. This would not be a new DX record but it would be another new country. The OY6FRA club station's antennas are shown on the left.

Sunspots on track

Latest graphs (March 2 2010) from the NOAA space weather site suggest that the smoothed sunspot number predictions are on track with a maximum of 90 forecast to occur in May 2013. This is not a high number but would still suggest excellent conditions on 15,12 and 10m from later this year until 2015. If you have not experienced 10m when wide, wide open then you are in for a nice surprise: dust off your QRP rig, put up a 16 foot long dipole and work the entire world!  Better HF conditions are already here and they will only get better still as the year progresses.

10m is calling me

As I sat winding my ATU for 500kHz this evening my thoughts were again turning to 28MHz. Although I've plenty of ways of getting on the 10m band already, I've always fancied a simple homebrew rig either for CW or sideband.  One idea is to make a QRPp WSPR beacon that I could leave running almost continuously. I've a 14.060kHz crystal that might just make it to 28.124600 when doubled in the right circuit. Into a simple phasing SSB circuit and I could have a few milliwatts of 10m WSPR.

Change to 500kHz ATU

This evening, as an experiment, I rewound the tapped coil on on ferrite rod based table-top ATU for 500kHz using 0.56mm enamelled wire rather than 0.2mm. The antenna current was up by (at most) 20%,  but on-air it made no difference with reports on 500kHz from M0BMU being the same as before. Before I put away my 500kHz kit for the summer I may try an L vertical with a 15m long horizontal top as I have access to a nice tree in my neighbour's garden which would provide a convenient support for the far end.

A new personal WSPR DX record

This evening I put the WSPR beacon first on 20m and then 30m running 1W into the 5m long vertical matched with the Elecraft T1 auto-ATU. First came a report from a VE6 in Alberta on 20m then a new DX record on 30m with a report from VK2/VK6DI at 16969kms. Not bad going for 1W to an indifferent antenna. Some of the European reports suggest that I'd still have been heard in Europe with just 5mW. VK6DI is a QRSS and weak signal mode enthusiast: see his site at http://www.users.on.net/~davroz/vk6di/

Receiver for 8.97kHz DX experiments

Jim M0BMU successfully copied signals from DK7FC on 8.97kHz VLF last weekend using a small loop antenna and preamp feeding into a Spectrum Lab soundcard VLF receiver. I've put a copy of Jim's latest preamp on my 9kHz page on my website. Others have tried voltage probe antennas.