Voice powered transatlantic 20m test

AA1TJ's historic attempt to span the Atlantic with just a "voice powered" TX (powered only with DC generated by rectifying audio from a LS into which he was shouting) started at 1500 UTC on Tuesday Nov 10th. Power out was about 15mW QRP from the coast of Maine, USA. They had a 2el vertical antenna aimed at Europe and a good clear sea path, but unfortunately the test was unsuccessful, although they did make contact (not voice powered though) with Europe on 160m QRP. For a report see http://www.QRPme.com .

Norway gets some new bands

Stations in Norway now have new, quite large, allocations at 500kHz, 5MHz and 70MHz as well as certain other changes. If you can read Norwegian, see http://www.lovdata.no/ltavd1/filer/sf-20091105-1340.html ).

SM6BHZ hears me on 500kHz WSPR

SM6BHZ heard me at last on 500kHz WSPR at 0556z this morning, so my best DX has now gone up to 951kms with the tiny station. He reported my WSPR signal at -26dB S/N. The distance beats my previous record on the band by almost 100kms. Gus, thank you so much for country number 6 on the band and Joe K1JT for designing the software to make this possible.

Climate change - Copenhagen

A binding agreement in Copenhagen next month seems to be slipping away because no-one wants to make firm commitments on the reduction of harmful greenhouse gas emissions. Personally, I think it would be a tragedy if our leaders came away with just a "wishy washy" set of political statements and nothing concrete. See http://news.bbc.co.uk/1/hi/sci/tech/8345343.stm . For the sake of our children and grandchildren we need ACTION from our statesmen, not words.

500kHz improvements - summarised

The spiral top-hat on the 500kHz antenna.

Since first putting a signal out on 500kHz a few months ago, I believe the ERP has increased by about 18dB. These steps were:

• Initial PA 500-700mW (0dB reference)
• PA output increased to 5W (+10dB)
• Additional grounds added (+2dB)
• Antenna spiral top hat added (+6dB)

No further changes are planned as I am close to fulfilling my original objectives of seeing how effective a small and simple QRP 500kHz station could be. The two remaining goals are to get reports from Germany and Sweden.

After that, it will be farewell to 500kHz and welcome to the next challenge!

ERP increased on 500kHz (6dB up)

Today I modified my 500kHz antenna introducing a spiral inductance/ top capacity hat consisting of around around 8 "spiralling in" turns in the space occupied by the original 28MHz halo. Seeing my initial reports from M0BMU I am some 5-6dB stronger than I was before, I guess because more of the antenna current is in the 6m long vertical section.

Three new 500kHz reports overnight: F4DTL, PA0AM and G4CAO. The improved antenna efficiency is definitely helping. Also my strongest report yet from GM4SLV.

Top Band WSPR

This evening I moved from 500kHz to 160m to see if I could improve my WSPR DX on topband. At first try, GM4SLV heard me up in the Shetlands. As for 500kHz, my ERP will be considerably lower as I am only using a short 5m long vertical tuned with a ferrite rod ATU. See John's screenshot, that also shows some digital QRM on the same frequency. At 2116z John was copying me on 160m when I was running just 100mW from the TX.

24 stations hearing me on 500kHz

This evening I received a WSPR spot report from F4EMV who is 433kms to the south of me. Yesterday I had one from F0DVZ. This brings the number of different stations reporting my signals on 500kHz to 24 (22 on the WSPR database and 2 others).

Planned 500kHz antenna changes

Before the end of the weekend I intend,weather permitting, to make changes to my small 500kHz antenna. These changes will be:

1. The 28MHz halo and 6m long feeder will be replaced by a spiral top capacity hat and a slightly longer vertical wire. The effect should be to increase the effective height of the antenna a bit.
   
2. Move my TV antenna away from the pole carrying the 500kHz wire. At the moment this is on the same pole, so is probably absorbing energy.
   

Taken together, I expect another 2-3dB improvement in antenna current and ERP. If these improvements work I'll give it an "on-air" test for a week or so. After this, I'm not planning any further 500kHz improvements as I'll have run out of "keep it simple" options.

More voice powered DX in the USA

Mike Rainey AA1TJ has pushed his DX up to 1329kms on 80m using his Code Talker TX (see left) which uses only the energy derived by shouting into a loudspeaker to power the transmitter - no external DC power sources at all. He worked W4OP at 0133z. Just visible is the tin can used to focus the shouts into the LS cone! I am beginning to think Mike will work some serious DXCC countries in the years to come using his "voice powered" TX. Imagine this rig into a beam on 10m when the sunspots are high.

Mike tells me he is having a go at a 20m version now.