30 Sep 2011

A decent 500kHz allocation a step nearer?

From a post on the GQRP Yahoo group....

"On the IARU Region 1 website Colin Thomas, G3PSM, reports on progress in Mainz towards an Amateur Radio allocation in the vicinity of 500 kHz.

WRC12 Agenda Item 1.23 says "To consider an allocation of about 15 kHz in parts of the band 415-526.5 kHz to the amateur service on a secondary basis, taking into account the need to protect existing services;"

The CEPT Conference Preparatory Group Project Team C (CPG PT C) meeting took place in Mainz, Germany and Colin Thomas, G3PSM, reports:

At its meeting between 26 and 29 September, 2011 the CEPT project team approved a draft ECP for an 8kHz-wide band between 472 and 480kHz. This draft ECP now goes to CEPT's Conference Preparatory Group for formal ratification in November. This breakthrough, at the 11th and final meeting of the project team, occurred with the submission by the UK's Ofcom of an RSGB-drafted compromise ECP proposal supported by France and Sweden. But the prospect of an agreed CEPT position is good progress, representing a 48 country block vote going into next year's WRC-12. It needs to be noted that the draft ECP comes with significant caveats to avoid interference to the primary user, as well as the existing secondary user services. These are the maritime and aeronautical radionavigation services respectively. As secondary users we would also not be afforded any protection. It should be acknowledged that we have had support from a number of Region 1 national societies in getting to this position."

Hospitals and life's (nasty) surprises

Yesterday we had a sudden shock when my wife was rushed into Addenbrookes Hospital in Cambridge suffering from severe back pains and sickness. The day before she had been fit and well. She has been diagnosed with acute cholecystitis and is now on intravenous antibiotics and drips.

As Julian G4ILO has recently found, life has a nasty habit of suddenly throwing a spanner in the works, usually just when things are going very well. Hopefully she will make a full recovery although she has to have her gall bladder removed in the next 6-8 weeks.

....and I haven't a clue how to drive the washing machine :-)

Reverse Beacon Network - brilliant resource

A couple of times in the last few days the Reverse Beacon Network (a worldwide network of receiving stations automatically uploading spots to to the internet) has come to my aid. Today for example: a couple of CW calls on 28.060 with 5W to the halo got no audible replies, but a RBN report from PJ2T in Curacao in the Caribbean at 10dB S/N on CW proved my signal was getting a very long way.   A few days ago I found my brief call had been copied in K3 land (that's the call district and not the Elecraft factory)..

28 Sep 2011

Sputnik across the Atlantic today

The "team" today
This afternoon Andrew G6ALB, Ted G4NUA and I got together to finish building the "Sputnik" transmitter for 15m based on old Russian valves of the same type used in the first Sputnik satellite in 1957. These were given to us by AA1TJ. Andrew G6ALB did all the building work but I was the "air tester" as his CW is, he says, worse even than mine.

After a few false starts with the PSU arrangement we fired up the transmitter into Andrew's inverted-L antenna and had almost immediate success with a QSO (following our CQ) with K1GDH (Ed) near Cambridge USA who was running 5W and gave us 539.

From Andrew:
Our power out was 400mW.  PSU was nominal 24V AC @ 500 mA plug top followed by doubler for about 74V no load and 72 on load.  Grid Block keying uses -36V rail.  In all 3 diodes, 3 caps, 3 bleed Rs.  Very simple, fairly safe also. Filament supply is 5V DC plugtop [stabilised] and 18R resistor which gets warm!
A second Sputnik rig is being built now and all being well we will be on the air on Oct 4th (Sputnik Day) to try for some more QSOs.

27 Sep 2011

Disappointing day on 10m today

Most of today 10m was relatively quiet here with just inter-G WSPR reports. I was about to switch things off when I noted a report from CX2ABP (11127km) just appeared. Maybe tomorrow conditions will be better.



26 Sep 2011

10m - AMAZING propagation again today

Starting with reports of my QRP WSPR signal from VK6BN at 0640z, the day on 10m has been simply amazing. The band has been WIDE open to all continents today and sounded (almost) as good as I ever remember it. Several USA stations worked (with 59 reports) on QRP SSB. One report on WSPR from VK4 suggested just 50mW would have been enough to get me reports from Australia!

I just hope this upsurge in conditions lasts a while. Just maybe, the peak of cycle 24 could yet be a good one. An indication of conditions is how far above 28.5MHz stations spread out. Stations were spreading out to at least 28.6MHz on SSB and this is a weekday with no contests.

25 Sep 2011

10m WIDE open - best for me in MANY years

Having just got back from France I switched on the FT817 on 10m to find the band wide open. Not that much on SSB (W4, 5B4 etc) but on WSPR with just 5W to my halo I was getting reports right away from the southern USA (-12dB S/N from W4DJW at 6537km and KB9AMG at 6300km). K9AN was giving me reports of +5dB S/N suggesting 5mW would be enough to cross the pond. Sounds like this autumn conditions are going to be excellent in 10m and possibly 6m.

UPDATE at 1845z: band still open to the USA, S.America and Europe. Just like the "good old days"!

19 Sep 2011

Earth Mode VLF article in October RadCom

If things go to plan, there should be a 3 page article of mine in the October RadCom. As I am away in France I've no idea if this appeared or not.

IC7000, FT450D or KX3?

After many years I am thinking of upgrading my "main" HF/6m rig and these are my main options. Any views on which one to go for? I shall only use the rig for QRP mainly but a bit more power could be useful at times. VHF and UHF could be a nice addition with the IC7000 but the FT450D has better reviews. Of course the KX3 is some months away from production, especially in a CE approved European version. Ideally I'd like an FT817 successor, but this doesn't look likely before I die.

18 Sep 2011

France

Enjoying a few days in the Perigord region of France with excellent scenery, history, food and wine. Rural France remains very unspoilt and beautiful. No ham gear with me at all though - too busy relaxing.

11 Sep 2011

Nuclear Fusion - our energy needs met soon?

Nuclear fusion plant of the future
Are we getting close, at last, to making clean nuclear fusion, as opposed to dirty nuclear fission currently used in power generation, a reality? The BBC reports that the UK has joined a project with a US laser lab to work on the creation of powerful lasers to compress atomic nuclei to the point fusion occurs. See http://www.bbc.co.uk/news/science-environment-14842720. If this breakthrough can be achieved commercially it could radically change the outlook for the world. Growing energy costs prohibit widespread creation of water desalination plants, desert irrigation, electric cars and the like, but think what would be possible if energy costs became inexpensive and plentiful for ever. Global warming is only too real, but I have faith that with strong investment and push we will make nuclear fusion a reality in the next 30 years. This could well save the planet. The main dangers on the way are the vested interests of the US petrochemical companies who will do everything possible to bias US government policy in their favour, denying vital fusion research the funding it needs.

8 Sep 2011

Success on 137kHz QRPp

 My 137kHz 0.2mW ERP signal by M0BMU at 69km
Today has seen some very encouraging results achieved on 137kHz with the QRSS30 0.2mW ERP beacon. Firstly copy from G4AYT in Whitstable Kent at 118km (in the null of my TX loop antenna) and excellent reception by M0BMU using his ferrite rod antenna at 69km - see screen shot. Several more stations are looking out for the signal which will remain on overnight.

LF kit improvements

24W 137kHz QRSS30 beacon TX (ERP 0.2mW)
137.5kHz 24W transverter (for WSPR) 0.2mW ERP

Today I completed the first stage of my ERP improvement programme on 137kHz completing the rebuild of the QRSS30 beacon and the transverter used for WSPR on the band. Photos attached show both of these. My ERP has now increased to around 0.2mW with both rigs. The output from the PA stage in both rigs is around 23-24W. More power will be easily possible by raising the PA supply voltage later.

7 Sep 2011

Sputnik valve TX tests

This afternoon G6ALB and I got together to build a 2 valve 21MHz transmitter using a couple of Russian valves of the same types used in the original Sputnik 1 satellite in 1957. Surprisingly I've never built a valve transmitter before. Even today, Andrew did most of the building. My input was to wind a toroid and to help sort out the wire ends of the two valves. The valves were kindly supplied by Mike AA1TJ.  The breadboarded TX is shown in the picture. On a test this evening over the 3km path between our QTHs the 400mW TX was copied fine on my IC703 and 10m halo antenna.  Even at the lowest HT voltage (around 30V) his signal was still solid copy on the "Sputnik". Our aim is to have a pair of these units ready for Sputnik Day (Oct 4th) and to work each other and other more distant stations who are using similar rigs.  See also http://aa1tj.blogspot.com/2011/07/sputnik-qso-party-transmitter-prototype.html

6 Sep 2011

Higher power on 137kHz

Today I did some work on increasing the output power of my 137kHz transverter used for WSPR, with mixed results. When driving the IRF540 PA with a decent square wave I can get around 24W out (was around 5-8W) from a 13.8V supply with decent efficiency. When using the drive from the mixed-down transverted signal I am having less success. The issue is driving the MOSFET gate from a really low impedance and ensuring it is as square as possible with the right mark-space ratio. Most 137kHz transmitters do this by driving at 274kHz with ICs designed to drive a pair of MOSFETs whereas I want to go in at 137kHz using discrete parts. This is a solvable challenge and I'll have this up and running in a few weeks. 25-30W would give me 6-8dB ERP improvement and more should be possible from a higher PA supply voltage. This would take my ERP up to around 0.5mW  ....heck that's high power for me!

5 Sep 2011

More QRPp testing on 137.7682kHz

My QRSS30 137.7682kHz beacon is on until 0800z Tuesday morning sending XBM in QRSS30 with the full call at 10wpm periodically for full ID.  Reports (including no copy) would be much appreciated.  I'm hoping to improve on the recent best DX a few days ago - a report from G3WCB at 101km who got the signal pretty well at times despite the 140uW ERP.

4 Sep 2011

CW training on the internet

If, like me, your morse code could be improved then you may like to go to http://lcwo.net/main and see the array of training material available there. It is probably the best place on the internet where you can brush up your skills.

Sunspots

At the moment we seem to be seeing quite impressive sunspot numbers, at last. See http://www.solen.info/solar/ . This bodes well for this coming autumn and winter which should see 10m well open to the USA on a regular basis by October. Such conditions offer the chance of transatlantic AM QSOs between 29-29.1MHz even with quite low power. In previous sunspot maximums it has been possible to work AM DX with just a few watts to a mag-mount on the car. AM makes a change from SSB.

Boy's Book of Crystal Sets

One of my favourite books when I first got interested in radio back in the 1960s was the Babani series book number 126 entitled The Boy's Book of Crystal Sets. The link takes you to a PDF copy of this book. I was fascinated by the shortwave version shown in the book and remember building a variety of it using parts I had. It was such fun copying distant DX stations with something so simple. Years later I managed to copy Radio Havana, All India Radio and even (directly from Australia) Radio Australia on a simple crystal set. All good simple fun showing the magic of radio. There are several websites on the internet today dealing with the design of sophisticated crystal sets capable of quite exceptional preformance.

1 Sep 2011

Improved QRSS30 beacon on 137.769kHz

This afternoon I did some experimenting with some new 42mm 3C90 toroids and my 1kV WIMA polypropylene capacitors. I've managed to increase the RF output of my QRSS3/30 beacon by around 5-6dB so I've put this on beaconing over the evening and overnight period in the hope that someone will see the signal and send me some screen shots. ERP with this new beacon is around 150uW.  Previous tests with the beacon ERP at around 50uW showed that the signal could be detected in The Netherlands. Each dB gained should improve my chances of being seen ever further. The screenshot shows my signal as received 101km away by G3WCB - quite a good signal at the peak of fades.