500kHz WSPR tonight

My last post with this title got corrupted when I tried to edit it, so this is a shortened revised version. 500kHz WSPR this evening has been very good. In the last couple of hours I've been getting 8-9 reports with each transmission slot when running less than 50mW ERP. Best DX 707km to DG3LV.

500kHz WSPR reports this evening

I've downloaded the latest version of JT9 software and hope to try this for 2-way QSOs later this week on 500kHz. My current problem is the S8 noise floor which I hope to reduce by using a better sited E-field probe or loop antenna (for RX only) further away from the house.

There are still plenty of CW stations on 500kHz. One evening last week I had a very enjoyable CW QSO on the band with G3XIZ. Semi-locally there are around 3-4 stations on a regular Sunday morning 500kHz CW net.

Projects pause

This week I am having a bit of a rest from amateur radio. We have two of our little grandchildren staying with us until Sunday and they take top priority. Anyway, one sleeps in my bedroom shack!  So it is off to ride on toy tractors, eating some cakes in a cafe and help Grampy deliver poppies.

With the XYL and grandchildren

There are some geomagnetic storms around so HF conditions are unlikely to be very good for operating.

Next week should see me back in action. My first task is to make some changes to the 472/500kHz transverter - adding an additional filter as shown in the Rev H schematic on my website so that it meets FCC requirements before an article on the small transverter appears in QST magazine next year all being well. It has been accepted. I've also got to update the schematic and parts list.

Next on the list is probably to get my 10m halo down for its rebuild that didn't get done last week. Then I am in to several possibilities including getting "Lesser Chirpy" going on air (the chirp free version of Chirpy) and casing it up. Also, there is the 481THz NLOS beacon with those BIG powerful LEDs I bought a month or so ago. There is also a new 136kHz transverter (like the 472kHz design but for 136kHz instead). And then there are all sorts of other ideas floating around in my head which probably won't get done for another year. These include a simple Fredbox version for 10m AM, an ultra-stable GPS locked frequency source to use on VLF and maybe microwaves later,  my permanent E-field probe and grabber for VLF/LF/MF,  an improved 136kHz stand-alone receiver, etc, etc. Hey ho!

More DX on 10m today

This must rank as one of the most fun CQWW DX contests I've taken part in. Plenty of DX could be worked with just 5W SSB from the FT817 and my small Homebase-10 halo today and yesterday. If anything conditions were better on 28MHz today than yesterday.

HK1NA (worked today) operating CQWW

 ...and in contrast G3XBM operating CQWW today!

Stations worked include LR3M, LP1H (Argentina), C5A (The Gambia), HK1NA (Colombia), CR2X, CR3A, CT3HF (Azores), CN3A (Morocco), ER3AU (Moldova), A65BB (UAE), 3V8BB (Tunisia), ZW5B, ZZ2T, PY1NX, PS2T (Brazil), EY8MM (Tajikistan) plus loads of US, Canadian and other stations. My ears are sore with SSB signals! I have now filled my third page of contacts in the logbook.

Some of the operating skills were amazing: PJ4X was working stations at a rate of one every 5 seconds. He spoke so crisply and quickly that by the time I'd called he'd already worked another station! 

First signals seen on JT9-2 mode

On 500kHz this morning PA0A and G3ZJO were testing with the new JT9-2 weak signal mode. Not yet copied Eddie, but PA0A was coming through well. This is a screenshot with his decoded signal overlaid.

500kHz first JT9-2 signal received

Choice DX on 10m SSB today

The CQWW DX Contest continues to brighten up things on 28MHz SSB, although the competition is fierce for some of the rarer stations.

XV1X QSL card

Some DX is surprisingly easy to work though, responding after just a couple of calls with QRP.  My 5W QRP SSB got through to EY8MM and A65BB but failed (so far) to work XV1X (Vietnam) or JT1BV (Mongolia).

JT9: a new digital mode for MF and LF

Hot news from Joe Taylor K1JT on the RSGB LF Yahoo group this evening about a new 9-FSK digital communications mode (for 2-way QSOs rather than beaconing) optimised for MF and LF bands. With winter approaching and better LF conditions, this is an exciting development.

The wide graph display for JT9

"I invite you to try a new digital mode called JT9, designed especially for making amateur QSOs at MF and LF. JT9 uses the structured messages introduced in 2003 for the JT65 mode, now widely used for EME and for QRP operations at HF. JT9 can operate at signal levels as low as -27 dB (in a 2500 Hz reference bandwidth), with one-minute timed transmissions. It also offers slower transmissions of 2, 5, 10 and 30 minutes duration, and the slowest mode can decode signals as weak as -40 dB. With one-minute transmissions, submode JT9-1 has a total bandwidth of just 15.6 Hz -- less than one-tenth the bandwidth of a JT65A signal. The other submodes are narrower still: a JT9-30 signal occupies about 0.4 Hz total bandwidth.

Note that these JT9 sensitivity levels are comparable to or better than those of WSPR, which uses simpler messages and is not intended for making 2-way QSOs.  JT9 has much higher throughput and reliability than QRSS CW, including DFCW modes.

JT9 is implemented in an experimental version of WSJT called WSJT-X. Some further details can be found at http://www.physics.princeton.edu/pulsar/K1JT/WSJT-X_Quick_Start_Guide.pdf , and an early version of WSJT-X can be downloaded from
http://physics.princeton.edu/pulsar/K1JT/WSJTX_01r2695.exe.

Please note: WSJT-X is in an early development stage. A number of improvements and enhancements are already in the works, and others will surely be added. 

Your feedback will be much appreciated!

-- 73, Joe, K1JT"

CQWW SSB DX contest 2012 (28MHz) - a recording

Well, Oct 27th 2012 and the CQWW DX contest is in full swing. 28MHz is filled with SSB stations all the way from about 28.25MHz right through to 29MHz, with even a few SSB stations on top of the AM users around 29.05MHz. Conditions appear to be excellent for the contest and they are likely to hold up for tomorrow too.  I was able to work 5 continents in 50 minutes this morning with 5W SSB and a halo.
 
In 5 years or so, this day will seem like a dream with 10m probably dead and devoid of activity. So, for posterity, I made a sound recording late this morning of the 10m band as I tuned across it and later this video at around 1630z.

Here is an earlier sound recording CQWW SSB DX contest 1125z October 27th 2012. Recorded near Cambridge, UK.  Feel free to share/use this recording and video. I only made them for posterity so I can remember, in years to come, what 10m was like at a sunspot peak.

Chromebooks?

This week saw the launch of Windows 8. Also, Google launched a new Chromebook 11.6 inch PC manufactured by Samsung which is getting rave reviews. Chromebooks use Google's Chrome OS which is very much linked to Cloud based operation.  The new series 3 Chromebook is only £229 from John Lewis complete with a 2 year warranty. In the USA it is available for $249. Now, when I looked I could not see any amateur radio apps for this OS. They will surely come though.
UK retailers include PC World, Amazon and John Lewis. They seem to be selling FAST.

Although I am not sure why, this PC really appeals to me: it is simple, small and effective. The local machine remains uncluttered and safe to use as most of the applications work remotely "in the cloud" although Gmail, Goodle Docs and lots of other apps will work without an internet connection too.

Has any reader used a Chromebook? What were your impressions?

VLF DX radiated test results

My days long, continuous carrier test with G3WCD (32km) and G3ZJO (around 50km) around 8.977188kHz ended yesterday. I was using my 20m spaced earth electrodes with 5W out of the PA. The test was to see if anything at all could be detected well beyond the 6km I can repeatably obtain with QRSS3 earth-mode (through the ground) communications.  Despite the hint of a signal a couple of times on the G3WCD 45uHz and 22uHz grabbers, these proved to be false signals and nothing was detected.

Using Spectrum Lab, locked to a VLF MSK signal I am able to measure my TX frequency with VERY great accuracy, in fact to an accuracy of less than 1mHz. What this showed up was that my crystal controlled TX drifted (very slightly by HF VFO standards) about 13mHz over the 4 days of the test. Starting frequency was around 8.977177kHz and the final frequency 8.977190kHz. With shack temperature variations it may have moved slightly higher or lower too.

When the RX stations are looking for a very very weak signal in a bandwidth of 22uHz this means the signal is only "within band" for the FFT software to analyse for a brief period before drifting out of the measuring "bucket".  To have ANY chance it will be essential for me to lock the TX frequency so that it stays within a few uHz over a period of days. This could be done using a GPS reference signal or using Spectrum Lab. It is the latter that I shall be trying - receiving a VLF MSK signal on one antenna as the reference, then using SL to synthesise the continous TX carrier which is transmitted on a second antenna.

In reality to get 32km on VLF with my set-up was always a "long shot", but all parties agreed it was worth trying and we have all learned a lot in the process. Experimentation is the name of the game and failure is as important as success.

It may be some time before I try the long range VLF tests again: I hope to have over 100W next time and a super-stable TX signal. Who knows, we might just succeed next time.

For information on these software packages (all free) that I use at VLF see https://sites.google.com/site/sub9khz/software .

My 10m halo - soon time for an overhaul

After the CQWW DX contest this weekend I plan to take down my Homebase-10 halo and rebuild it. The birds have managed to tear away at  the nylon rope supporting the nested 6m halo and the wooden supports now look a bit weather beaten.

So, I plan to replace the wooden cross frame supports with PVC pipe or fibre glass rods and re-do the wire elements. These have been up in all weathers for around 4 years now, so a few pounds on a remake is justified. The antenna works so well and is so small that I cannot think of a better antenna for the 10m band short of going to a beam which would be huge by comparison and need a rotator. The neighbours are quite used to it too, which is good.