29 Jan 2014

PA1SDB on VLF

PA1ASB has been active recently on VLF and on his site he has a grabber showing what signals he has/is copying around 8.270kHz  which is the new favoured spot. This is below 8.3kHz and so falls in the unallocated part of the spectrum as 8.970kHz is now within the  spectrum reserved for sferics research.  Most amateur VLF TX stations are now operating around 8.270kHz. Here in the UK I believe it is legal for ANYONE to TX below 8.300kHz  as long as no harmful interference is caused to allocated services above 8.300kHz. This is my view, not a legal statement. I have asked OFCOM to clarify.

Also of note on these pages are the .SDR configuration files for Spectrum Lab software. It is ESSENTIAL to use Spectrun Lab or very similar software to detect anything at any range. See http://www.qsl.net/pa1sdb/index.htm . I suggest that, if you want to build a VLF amateur RX, to base your configuration files on those given on these pages.

My own experience is that 420uHz or less bandwidth is essential to see any trace of amateur VLF signals integrated over many hours. 42uHz is better. In both cases you have to lock to a VLF MSK signal, Russian Alpha beacons or GPS for excellent stability. This is all sorted out with the .SDR file automatically. You may be surprised  how stable a RX you can make very simply.


28 Jan 2014

Our windmill in action

As you may recall, last summer we moved to a bungalow right next to Burwell's 200 year old windmill, which is being fully restored thanks to a National Lottery grant. The video shows the 4 (new) sails being tested earlier today as seen from our lounge window. It is very impressive.

Right next door is the local museum (excellent) which is open Thursday and Sunday afternoons from Easter until late October and WELL worth a visit.

The windmill appears to wobble because Google removed the video's shakiness -in reality it is very stable.

6m - no good today

After a full day on 6m WSPR not a single entry in the log.Even the spots by G4IKZ,were last evening!  Even othersmdid not seem to be doing very well either.

Meanwhile, 10m was in good shape yet again with lots of transatlantic stations copied and worked by G4NUA, a friend in Cambridge.

I'll keep 6m WSPRing for another day, and hope for better solar conditions tomorrow.

73kHz UK access?

According to my interpretation of the latest UK frequency allocation table, one can use the old 73kHz band without a license as long as the output is less than 72dBuA/m at 10m under inductive devices rules. Perhaps someone can tell me if I am wrong. A very low ERP is not a handicap as amateur antennas tend to be VERY inefficient.

See http://stakeholders.ofcom.org.uk/binaries/spectrum/spectrum-information/UKFAT_2013.pdf

6m F2 DX

Unless it was a band error, yesterday early morning G4IKZ 18km west of me was spotted on 6m WSPR in Australia over 17000km away by rare 6m F2 propagation. Nick uses about 6dB more power than me and a Moxon beam whereas I use a V2000 vertocal with near unity gain on 6m. I am currently on 6m and living in hope! Solar activity does NOT look promising though.

27 Jan 2014

FT817ND - the perfect QRP radio?

For some time I wondered why Yaesu had not replaced the FT817ND with a more recent model. Then, of course, the penny dropped. This radio, although not perfect, is a good buy at around £500 in the UK.   Basically this is still a very good little radio. Expect a further price drop with the latest £:yen exchange rates.

All it needs are better batteries, auto-ATU and a speech processor, all which can be easily added to the FT817. The KX3 is twice the price of the FT817 and this does NOT include 2m and 70cms all mode. No, for me it will be a second FT817, this time the ND version plus another auto-ATU.

At some point a newer version may appear, but the current version regularly scores well in the eHam reviews (4.8/5) because those who own the radios know just how good they are. Of all the radios I have ever owned and used, the FT817 is the very best, without doubt. Someone called it the "Swiss army knife" of radios.

See the Yaesu brochure at : http://www.yaesu.com/downloadFile.cfm?FileID=618&FileCatID=154&FileName=FT%2D817.pdf&FileContentType=application%2Fpdf

G4KPX

If you get a chance, look at the WSPR spots for Richard G4KPX. Unless he has made recent changes Richard uses QRP with indoor loop antennas and achieves excellent results on every band he uses. For example, his 0.5W 10m log includes a couple of VKs and a good array of stateside stations.  Even on 472kHz he achieves good results.

Back on 10m

After a night looking on 160m RX I came back to 10m TX/;\RX WSPR at 1000z this morning. After a quiet start I am (again) being spotted by 4X1RF and am seeing a station in S.Africa ZS4A (9357km) and Japan JG1KGS (9512km). The band is in good shape yet again. In the afternoon, the band was (again) wide open to the USA and Canada.

UPDATE 1904z:  For me here, the 10m band was STILL open transatlantic at 1904z, VERY late indeed and way after dark..

26 Jan 2014

Top Band WSPR

For a change this evening I've been looking on 160m WSPR with my totally untuned Par 10/20/40m antenna and my FT817.  It is quite amazing what this far from optimised set-up can pick up (see below):
Unique 160m RX WSPR reports since yesterday afternoon
I am unable to TX on 160m, so this is just what I have been able to spot. Best DX was OH6HRX at 1814km.

JT65-HF QSOs on 10m

Today (in between doing the RSPB annual bird count) I had some digital QSOs on 10m with Europe and N. America. The mode works with weak signals but it takes several minutes to complete a QSO. I also tried JT9-1 but there was no activity when I was on. WSPR is easier but does not really support 2-way QSOs whereas JT65-HF and JT9-1 both do.
JT65-HF QSO today