15 Mar 2010

10m open

Several Italians coming through on 28MHz WSPR this morning and giving me respectable reports with 1W into my halo. Not sure if this is sporadic-E or F layer. Also coming through around 11.30am was  the 5W WSPR signal from FR1GZ (Reunion Is) at -24dB S/N.

This afternoon another interesting exchange of WSPR reports with PC1CP 448kms away in JO33 square. My report was -24dB S/N with 2W to the halo and he was -17dB S/N with 5W. This distance is quite an odd one on 28MHz as it is too short for sporadic-E, so this was probably by tropo.

14 Mar 2010

New German amateur test on 8.87kHz planned

Stefan DK7FC is hoping to do a second test transmission on March 15th on 8.97kHz using a vertical antenna, new large loading coil and variometer. Transmissions should start around 1400z. Several stations will be listening and the DF6NM 8.97kHz grabber will be active. Stations possibly within range are DF8ZR (16kms) and  DD7PC (53kms).

8.97kHz does look like the new frontier!

85 unique reports now on 500kHz with 1mW ERP

With a report yesterday from PA3EGO, the number of stations who've reported my signal on 500kHz WSPR and CW has now risen to 85 so far since last September. It's pleasing to see new DX reports coming in despite the less effective antenna now in place i.e. the 10m halo and its 5m of feeder coax. I'm actually finding the reports are not that much down, if anything, on the top spiral loaded vertical.

iPOD - 1940s style

This was posted on the QRP newsgroup today. Wonderful idea.
http://www.retrothing.com/2010/03/vacuum-tube-radio-hat.html

VKs coming through on 10m CW

VK6DXI was a good signal (579 at times) in the BERU contest this morning on 28.006MHz CW. I called several times with my 5W QRP but did not get through. Conditions on 10m are on the up!

13 Mar 2010

8.97kHz VLF grabber on-line in Germany

DF6NM in Nuernberg, who has been successfully experimenting with sub-9kHz communications now has a temporary grabber on-air to capture any amateur signals on 8.97kHz.  See http://www.mydarc.de/df6nm/vlf/vlfgrabber.htm

500kHz CW QSO this evening

For a change I went on 500kHz CW and managed to get a 579 report from Chris G3XIZ. Chris then went on to work PA0WMR although the Dutch station was only about 559 with me. I called him but he did not hear me.

Useful American sub-9kHz experimental VLF site

VLFradio.com is a most interesting site. Among the stuff there are the results of some induction communications tests with a 90m circumference TX loop out in the desert away from man-made interference. Using just 0.5W a range of 1 mile (1.6kms) was achieved at 1.8kHz and with higher power up to 2 miles (3.2kms). These signals were copyable by ear, so further still would be possible with weak signal techniques. Also on the site lots of recordings of these tests as well as other VLF noises and man-made transmissions

12 Mar 2010

Another country using the "degraded" (?) 500kHz antenna set-up

As I mentioned a few days ago, I took down the main 500kHz vertical so I could re-erect the 28MHz wire halo with coax feeder. I'm using this, with feeder inner/outer strapped, as the antenna on 500kHz now. Actually the reports aren't much worse! This evening I got +1dB S/N from F6CNI which is a typical report from him at 418kms on WSPR.

Sub-9kHz induction comms resource

John F5VLF/G3PAI has brought a very useful website about induction mode communications below 9kHz to my attention. This site is mainly about cave location and beaconing systems, but there are some neat schematics for local coverage (thousands of feet range) TX and RX circuits that would be suitable for QRSS and similar experiments in the "Dreamers Band" as some have called it. See http://radiolocation.tripod.com/