26 May 2011

The Elecraft KX3 Ultra-portable multimode QRP rig

There is much excitement about the latest product from Elecraft, the KX3. This was announced at Dayton and it looks like a marvellous addition to the Elecraft range. See http://www.elecraft.com .

The RSGB Luso Tower fiasco

Some time back, the RSGB bought a huge Luso tower - list price £31k, although they got it for less - but are now selling it for £13.5k as they can't get planning permission for it at their new home at Bletchley Park.  What has this sort of monster got to do with amateur radio? What sort of example is our national society giving to newcomers? Pay BIG money for everything to get a BIG mast, BIG yagi, BIG rig and BIG linear?

The RSGB must give more of a lead by showing that this does not have to be a "fat cheque book" hobby and that simple, low cost, equipment can be effective. RadCom does carry some excellent articles, but I fear many newcomers reading the magazine would come away thinking it's an expensive hobby.

25 May 2011

10m Sporadic-E and BIG signals

As an example of just how strong signals can be on 10m with strong Es conditions take the reports this afternoon from DJ0ABR. With 500mW to my halo he was giving me a WSPR report of +7dB S/N. This suggests I'd still be OK with just 500uW from the transmitter. I know others have achieve far better than this but it does remind you that a big sporadic-E "cloud" acts as a very good mirror.

Sepura introduce intrinsically safe TETRA portable

My colleagues at my old company, Sepura, have just released details of their new ATEX intrinsically safe TETRA portable. From my own experience of designing intrinsically safe products (PF2UBIIC, EXPF85) this is a far from easy task, especially today when the tests are even more extreme and challenging. Well done to the team involved.

Intrinsically safe radios are designed to be used in very hazardous locations such as oil refineries or petrochemical plants where the risk of explosion is high. They are designed to be safe even in certain fault conditions.

My first JT65 QSO

Although I've listened/looked at received signals with this mode, this morning I had my first ever JT65 QSO (using QRP of course) with EA1YV on 14.076MHz. I used the JT65-HF package with the simplified interface for HF QSOs. It worked a treat. See http://physics.princeton.edu/pulsar/K1JT/JT65.pdf.

As I've no antenna for 20m I just used my 10m halo tuned via the Elecraft T1 auto-ATU.

24 May 2011

4m transverter - some builder feedback

Just got this very nice email about my 4m transverter:

Hi Roger,
               My name is Mark (mi0bdz) and I was browsing the net for 70mhz projects when I came upon your site. I could hardly believe the simplicity of the little 70mhz  transverter you designed and built. I decided to copy it. I started on Friday afternoon after gathering the bits together and completed it by Saturday evening. I could not have done this without thanking you for sharing the project,  which I class as the best usable project I have come across in many years.
   I have found that by careful selection of the TX transistors and bias resistors that 3 watts is possible. I did have to alter the values of the bias resistors quite a bit, but that is all. Everything else is as your schematic. Thankyou again for a wonderful little project. This is a gem. The sensitivity is also excellent. You were right about packing a lot into a chip indeed. Thanks again Roger.


23 May 2011

Cycle 24 already peaked?

Check out recent trends - it looks like the present cycle has already passed it's peak. Or is this just a blip?

22 May 2011

6m Es

Well, the 6m sporadic-E season is in full swing again: yesterday loads of Europeans worked with QRP and the vertical and this afternoon being spotted in Spain with WSPR. Initially it's fun working around Europe, but as the season goes on the real excitement is further afield looking for US/Canadian and South American stations on 50MHz. It never fails to amaze me how far one can hear/work on 50MHz with the right conditions. Also, next month should see the return of UK-Japan openings on 6m possibly as a result of reflections/scattering from high altitude noctilucent mesospheric clouds; signals with this mode are usually very weak.

18 May 2011

Old QSL cards

Clearing the loft today I came across several QSL cards from my first year in Cambridge back in 1971 including this one from Bob G3WKW for a QSO across town using my 1 transistor 2m TX on CW and FM. I cannot recall the details or how I obtained the FM. Power was just a few milliwatts into a dipole in the downstairs room in a terraced house. Bob went on to work for Motorola before retiring in Hampshire a few years ago. We still keep in contact.

15 May 2011

137.5kHz WSPR

Several stations on 137.5kHz WSPR tonight. G4WGT is testing a new rig, M0PPP is getting decent reports and me getting reports from just G3XIZ so far. Will leave WSPR running for a few hours and see what happens.

14 May 2011

QRSS30 QRPp beaconing on 137kHz band

PA3FNY's reception of the QRSS30 beacon XBM (me)
My QRPp QRSS30 beacon sending "XBM" is active on 137.7679kHz (approx) from now until around 2300z. As before, any reports and screen shots would be much appreciated. ERP is still around 50uW. The last time it was on it was copied in Holland and again today, this time by Victor PA3FNY (see screen shot above) at a distance of 328km.

G3XIZ TXing on VLF today

G3XIZ is active this morning on 8.9766616kHz and clearly visible on the G3ZJO grabber in Northampton. His signal was a lot weaker than the last few times for some reason. I think the difference is at my end.

12 May 2011

Bloody-nosed beetle larva in IO80ef square

About 1.5cm long, behaved like a woodlouse.
Walking part of the coastal path in Devon at Prawle Point I noticed this very strange creature in the footpath a few metres from the cliffs. It looked a bit like a fat slightly iridescent woodlouse about 1.5cm long with a very wrinkled outer shell. There is a video of the creature moving at http://www.youtube.com/watch?v=rSDiJA1b1zM . It turns out the creature is the larva of the Bloody-Nosed beetle, which is quite common in the southern UK.

8 May 2011

A beautiful QTH locator square

Bolberry Down - Devon UK - IO81CF
Ever wondered what one of the most beautiful QTH locator squares in the UK looks like? Try IO81CF in South Devon. This is a view along the rugged clifftops just below Bolberry Down which was the location of one of the first ever 6m contacts between the UK and the USA by G5BY back in the late 1940s. I was walking here earlier today when this photo was taken.

ZEVS DXing on 82Hz (yes 82Hz!)

Several stations are reporting reception of the Russian ZEVS station that operates daily around 82Hz (ELF) sending coded messages to Russian submerged submarines. G3ZJO has copied it as has Chris G3WCD. When I get back from Devon I must try too. I think I should be able to copy it. The attached image is the signal as seen by G3WCD this evening. The signal is FSK coded. Data rates at these low frequencies are very low.

USA 4m beacon

WE9XUP is a new 4m beacon operational on 70.005MHz from FM07tm square that will be running 24/7 until 1.9.11. 4m is not allocated as an amateur band in the USA, so this is just a special propagation beacon. It could be a very useful indicator of multi-hop Es or other modes that may fleetingly open up the transatlantic path on 70MHz. Transatlantic 4m QSOs have been made cross-band more than once. I am not sure if this beacon supports weak signal modes like JT65 or WSPR, but that would be very useful.

7 May 2011

"Enough" - a book by John Naish

May I recommend this brilliant book reflecting on the sheer stupidity of our endless striving for better and more when we already have more than enough? We have evolved into a race chasing the impossible dream that ends up with us all stressed out, depleting our resources, unhappy and unfulfilled. The author argues we need to develop a cultural sense of "enoughness" and to be happy with what we HAVE rather than always striving for more and better.

I couldn't put this book down and all the way through was saying, "yes, spot on" again and again and again. Having read the book I doubt any of us will instantly change our ways, but just maybe we will reflect on our culture and modus operandi and think a bit more carefully about what is REALLY important in our lives.

The book is not a dull, environmentalist tome. Rather it is full of humour and light-heartedness. A truly excellent read for western man in the 21st century. I suspect this book will be seen in years to come as the book that woke us up and brought us to our senses in much the way that Rachael Carson's "Silent Spring" did back in the 1960s.

Robert Helliwell

The death of Emeritus Professor Robert Helliwell of Stamford University was announced today. Helliwell was the author of the book "Whistlers and Related Ionospheric Phenomena" back in 1965. This is a wonderful book on the subject of VLF atmospheric physics which is still available from Amazon.

My 50uW ERP signal at 45km on 137kHz in QRSS30

Chris G3XIZ has sent me a nice screen shot showing my QRP beacon signal a couple of days ago. The signal is in QRSS30 and as Chris says, certainly good enough for a 2-way QRSS QSO on 137kHz. Chris is 45km from me.

Bluebell woods

Just spent a pleasant afternoon walking through an old wood near where I used to live in Devon. The woodland floor was a carpet of bluebells and garlic flowers. This is the first time I'd been back there in around 40 years and it was as lovely as ever.

5 May 2011

Ultra low voltage oscillators

Thinking a bit more about my crazy idea for a mains hum powered QPRp beacon TX, I chanced upon this page which discusses FETs running from extremely low voltage supplies. See http://www.dicks-website.eu/fetosc/enindex.htm. Some of the zero threshold voltage MOSFETs (ALD110900A) used in sensitive crystal sets may also be useful in this application. The link shows an FET oscillator powered by just a thermocouple producing only 13mV! Incredible. See also http://cap.ee.ic.ac.uk/~pdm97/powermems/2009/pdfs/papers/069_0209.pdf and http://www.aldinc.com/pdf/Ultra%20Low%20Power%20Oscillators.pdf

4 May 2011

UK trains - actually pretty good

For the last couple of days I've been down in Canterbury visiting my son, his wife and our grandson. As my wife was busy I took the opportunity to travel alone by train. There is now a new high speed service from London to Canterbury that has slashed journey times on that part of the trip. All trains were clean, on-time, fast and comfortable. Also, at £25.50 return with my senior railcard, excellent value. We complain too often, but railways in the UK are actually rather fine of you can travel off-peak when the commuters are not crammed in. As an ex-trainspotter back in the late 1950s and early 1960s I still love trains.  Secretly I'd like a Ian Allen locospotter's book (now Platform 5 books) so I could collect numbers still, but would risk being called a sad anorak!

1 May 2011

325km with 50uW ERP on 137kHz

Well, Henny PA3CPM has just sent me a new screen grab showing my signal at 1041z today on 137.676kHz in QRSS30. This time you can make out some of the CW (visible just below the continuous Loran line) and the periodicity between callsign blocks is visible confirming this is indeed my signal.  Distance is 325km (202 miles) to JO22mb square. This is the first time my 137kHz signal has got into mainland Europe. I am amazed that a really simple beacon on a tiny board into a simple wire loop in the garden can span such distances. Even more amazed that Henny could find it!