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.

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.

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.

  Regards

             Mark

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?

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.

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.

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.

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.

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.

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.

"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.

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

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!

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!

Over 100km on 137kHz with 50uW ERP

Just got a screen grab from G3WCB 101km away showing my QRSS30 beacon signal being received at his QTH near Windsor. Mine is the lower trace in which you can see "BM" (part of XBM). It is not strong, but there. I will leave the beacon running with around 50uW ERP during today.

A few hours later G3WCB got me stronger with the XBM very clear on the screen.

Henny van Elst in Holland was also seeing traces at the right frequency, but too weak to positively identify.

QRSS3 beaconing on 137.6748kHz

My QRSS30 (slow CW) LF beacon has just been started up. I'm hoping that QRSS30 will get me reports from a bit further afield.  Any reports and screen grabs would be much appreciated. It will be on for much of the weekend unless I need the antenna for some VLF tests. The message cycle takes about 25 minutes and best results will be with Argo, Spectran or Spectrum Lab software on a PC and FFT bandwidths of around 0.1Hz.

Message:     XBM in QRSS30, pause, then G3XBM in 10wpm
Freq:           137.6748kHz
ERP:           50uW (antenna 80sq m vertical loop)
Location:    JO02dg, Burwell Cambs

2 transistor transceiver kit

The Four State QRP Group is offering the new "HamCan" transceiver kit for sale at just $30.  It is a 2 transistor crystal-controlled CW transceiver, delivering 0.5-1W TX power with enough sensitivity and selectivity to receive plenty of signals. They claim it is a minimalist yet good performance transceiver. The kit features a high quality PCB, low parts count and fast and easy building. It is claimed to be an excellent kit for first time builders. It has been selected as one of the ARRL Midwest Convention's Buildathon kits. 

More information at http://www.wa0itp.com/hamcan.html .

Mains hum powered beacon

Recent tests with earth electrodes at VLF have got me wondering about a simple QRSS HF/VHF beacon TX powered entirely from the rectified mains hum and other crud coming from a couple of earth rods in the ground.  Not sure of the available power, but I suspect it would be in the 0.1 to 2uW region, maybe more. This may be enough to drive a low voltage QRSS beacon for example. You can buy power harvester ICs these days for this purpose, but with a step-up mains transformer there may be a volt or two available at a few tens of uA and that alone may be enough to drive a keyed oscillator. The ultimate in free power beaconing!

3km DX on 8.97kHz WSPR today

This morning I successfully decoded a VLF earth mode WSPR signal from G6ALB at a distance of 3km. Signal was quite strong, but for some reason the WSPR software refused to decode it (apart from once) despite clocks being reset at each end. This is my best WSPR DX reception on VLF so far. Andrew was running 40W to an earth electrode antenna. I was copying him on an earth electrode antenna although the WSPR signal was stronger later on the 80m square vertical loop in the garden.

In the afternoon I used my wife's laptop and WSPR decoded every time at -16/-17dB S/N, a very decent signal. There is a video showing the VLF WSPR set-up if you want to see it. 

G3XBM is off to Mars

NASA is collecting names to be put on a microchip that'll be on the Mars Science Laboratory rover heading to Mars in autumn 2011. The rover has special CW indentations on its wheels spelling out  JPL (Jet Propulsion Laboratory).

To add your name/callsign go to http://marsparticipate.jpl.nasa.gov/msl/participate/sendyourname/

Bicycle portable in Blackpool

David G4AKC has been on his bike and working some excellent DX (like VK/ZL) on SSB and CW on 20m from his bike parked up next to the seaside in Blackpool. He uses and Alinco DX-70 on battery power with a  home made top loaded 3.5m long vertical against a tuned frame, and operating "over the sea water".  He says several QSOs were possible at the 1W level. See http://www.qrz.com/db/g4akc .

28MHz WSPR DX

Just a couple of outings on 10m WSPR this week, but some excellent reports from 5 continents using 5W and the small halo antenna. Interesting to see what must be Doppler shift drift on both the Reunion Is and Australian reports, presumably because of moving F-layer over the equator?

28MHz getting too easy?

For the first time in several weeks I put my WSPR beacon on 10m this morning. Without any effort, the 5W and the halo got reports from the Middle East and Australia. With the solar flux regularly above 100 now, I'm finding that 10m has moved into its "easy" phase when worldwide DX is becoming easy.  Also, with the Es season just days away now, the European activity will be plentiful and WSPR reports from Europe with microwatts certainly probable.

Solar activity heats up

There is a nice article on the NASA site about the recent upsurge in activity in solar cycle 24. See http://science.nasa.gov/science-news/science-at-nasa/2011/14apr_thewatchedpot/ . No-one has, to my knowledge, changed their views that this cycle will be a low peaked one. However, every solar cycle seems to be different and we can live in hope for a while yet.

Earth mode VLF test at 1.095kHz

When testing with utilities assisted earth mode in recent months I seemed to be getting weaker signals at 8.76kHz compared with my tests at 0.838kHz last summer. So, today I decided to go back and recheck results at a lower frequency at test sites 1.6, 2.6, 4.5 and 5.1km away from the 5W QRSS3 transmitter at home. Test locations were rural fenland roadsides, a National Trust car park and 2 roads in the next villages.

I used the same TX as at 8.76kHz, but divided down by a further x8 to 1.095kHz using the 4060 divider. The receiver was a horizontally orientated 30turn, 80cm across, series tuned loop into a low impedance MPF102 FET preamp with a drain circuit peaked at around 1.1kHz and emitter follower into PC running Spectran.

My initial test at 1.6km was a total failure - no signal visible at all in Spectran at 0.73Hz bandwidth. Then I realised that I had BOTH the garden earth electrodes in use at the TX (neither connected to pipes). A phone call to my wife and one wire was connected to the pipework in the house with the other still connected to the earth electrode at the bottom of the garden some 20m from the house. The signal then appeared at good strength.

Signals were received at all test locations indicated, but there was no signal visible (in QRSS3 bandwidths at least) when moving away from the roads into nearby fields or at some other test locations where pipes were absent (or plastic). At one location I rested the loop within 2m of one of the fenland water courses, but nothing was detected. The image attached  is the signal at 4.5km, which is strong in 0.79Hz bandwidth. Even stronger signals are possible with more optimum positioning, but I keep having to move my loop to avoid it being crushed by oncoming farm tractors! I do get some odd looks too.

My conclusions from the tests to day are:

• This was definitely utilities assisted earth mode. The initial (accidental) test today with 2 earth electrodes not connected to water pipes failed.
• Signals are strong close to where the metal pipes are, but rapidly disappear where no (metal) pipes are close by.
• Signals at 1.095kHz are definitely stronger than at 8.76kHz in the 3-5km range.

There is one more test to do at some point that needs some assistance locally (I think within 10km to work). I want to try a long stable carrier test with someone looking in the very narrow bandwidths we've been using for the radiated tests recently. What I'm wondering is just how far from the pipes does an earth mode signal "leak"? Using Spectrum Lab with the very weak signal bandwidths like 0.4-2mHz, the weak remnants of a signal might just be visible some way from the "easy" utilities assisted coverage area.

The remaining tests I want to do still with earth mode are:

• River bank or sea coast test - just how far can one get?
• True earth mode in open country without any utilities assistance
• Earth mode at higher frequency e.g. around 70kHz, which I can manage with my present set-up. Based on recent OFCOM correspondence I believe such tests would be legal as long as there is no intentional radiated signal or interference to others.

This class of experiment is not in the same league as those being done by the radiating VLF DXers, but fun nonetheless, especially as anyone can do this sort of test without NoV or special permits needed.

111km optical QSO in Yorkshire

G8AGN/P and G0EWN/P achieved a 111km speech QSO on optical communications using 0.5W red LEDs and Fresnel lenses on April 6th 2011. Brilliant stuff.

Heathkit from 50 years ago

Dave G3UUR pointed me in the direction of the 1961 American Heathkit catalogue in which I found the EW19 electronic workshop kit. My memory had this as the EW1, but I must have got this wrong. My mum and dad bought me this for Christmas 1961 and it was this that got me started in radio as a hobby.  The Medium Wave radio was used for my first DXing late in the evenings. Also, the simple MW transmitter (using the crystal earpiece as a mic) got me across the house - my first transmissions.

SAQ 17.2kHz this week

There will be an extra transmission with the Alexanderson alternator station SAQ on 17.2 kHz on Thursday April 14th 2011 at 12:45 UTC with tuning up some time before.   The transmission is directed to "The 5th European Conference on Antennas and Propagation" in Rome, Italy. There will be no QSL verification of this transmission.

An odd ladybird in a London park

During a picnic in London's Springfield Park today, a very strange ladybird (family name Coccinellidae) came to join us. I've seen red ladybirds with black spots and vice versa, but never a yellow one with white spots! Anyone know what sort it is?

Bell System Techical Journal now online

The complete Bell System Technical Journal from 1922-1983 is available on line and searchable. See
http://www.alcatel-lucent.com/bstj/ .

G3XIZ testing on VLF overnight tonight

Chris G3XIZ will be active on VLF again this evening and overnight on 8.9766616kHz although the start time is not yet known. My VLF on-line grabber is already on in readiness, as is the grabber at G3ZJO. Chris has recently been improving the match to his VLF loading coil and antenna and is working on a new variometer.