31 Dec 2011

Happy New Year

A very happy New Year to all readers of this blog.

2012 should bring us even better HF conditions as we approach the peak of Cycle 24. With luck and hard work we may get a new MF band around 480kHz. As ever, there are challenges from VLF to light beams to be enjoyed and I hope you have as much fun with our hobby as I shall.

My priority once the Christmas holiday is over is to complete my 481THz lightbeam transceivers and test these locally. Further projects will be to improve my VLF earth mode DX and to set up a lower noise VLF grabber in anticipation of more activity in the months ahead. In addition I shall continue with QRP WSPR and QRP operation mainly on 10m and 6m.

Netherlands on 500kHz and 70MHz

Some good news: amateurs in The Netherlands now have access to the 500kHz band (again) and 70-70.5MHz (4m).  Countries permitting 4m operation are growing every few months. Let's hope one of the major equipment manufacturers includes the band in multimode HF-6m rigs. Adding 4m cannot be too hard.

28 Dec 2011

Elecraft KX3 can now be ordered

On Dec 27th 2011 Elecraft announced that their new QRP radio can now be ordered with deliveries starting in about 8-9 weeks time. As a QRP radio the KX3 is likely to be "best in class" with some excellent features, but it is not low cost when loaded with options and imported into the UK after VAT and any duty is paid. See the KX3 page for more details.
The basic KX3 includes:

   * 10 watts output typical (13.8V) on 160-6 meters. (Up to 5W using internal batteries)
   * All modes (SSB, CW, Data, FM, AM)
   * Many features from the Elecraft K3, including the same full-size LCD
   * Advanced DSP features, including PSK31 and RTTY text display, noise reduction, auto-notch
   * Built-in 8-AA-cell battery holder
   * USB serial cable for firmware upgrades and for use with logging/contesting software

Available options include:

   * KXPD3 precision attached keyer paddle
   * KXFL3 dual-bandwidth roofing filter module for SSB/CW/Data modes
   * KXAT3 internal wide-range automatic antenna tuner
   * KXBC3 internal NiMH battery charger
   * MH3 hand mic with UP/DN VFO controls
   * RS232 control cable (optional replacement for supplied USB cable)
Although I certainly covet this little radio, I have not decided if I can justify the purchase, or indeed afford it!

24 Dec 2011

Happy Christmas

To everyone that reads this blog from time to time, may I wish you and your friends and families a very happy and peaceful Christmas. It is a time to both give and receive love and kindness - enjoy it.

Shortwave broadcast QSLs

Talking about QSL cards makes me think of my very first QSL cards received back in the 1960s. In those days I used the ISWL QSL bureau which handled broadcast band QSLs (I think it still does) and well remember the thrill when I got my very first cards. The first ever QSL was from Radio Nederland and it was an exciting moment. Somewhere I still have that red card with a windmill on!

In the subsequent years I did a fair bit of QSLing when using just my shortwave crystal set and got a few cards back from these reports. I heard stations all over the globe using that simple crystal set with best DX being Radio Havana Cuba, All India Radio and even Radio Australia, all direct and not via any relays. Not bad for just a tuned circuit, a diode a resistor and a crystal earpiece. I must have another go at a shortwave crystal set just for fun, especially as HF conditions are so good now, but these days shortwave broadcasting is not what it was. Using a decent toroid and a bridge detector it should be possible to arrive at a sensitive design with quite good selectivity.

WSPR QSL cards?

Just been having an interesting debate on Facebook about someone requesting an eQSL for an exchange of WSPR reports. Some would argue that, simply exchanging reports via the WSPR database does not constitute a "real" QSO, so a QSL is not appropriate. Indeed, some would say the WSPR database report is itself a confirmation of the report (which it is) so what is the point of a QSL card? On HF contests it is VERY common for only one callsign to be heard in reports such as, "G3XBM 599233 TU" yet such exchanges are used for DXCC credits if a QSL card is sent following such a "contact".

Personally I would eQSL a full 2-way exchange of WSPR data if done within, say 10 minutes, on any given band and consider this valid. I will only do this in response to one received. Others may violently disagree!

23 Dec 2011

Quartz crystal suppliers in the UK

Recently I wanted to buy a couple of non-standard crystals for a VLF project with the crystal divided down using a 4060 divider. After asking other people for advice it looks like Quartslab can provide the service.  Individual crystals range from around £12-14 depending on frequency and type.

This is not cheap, but at least they can offer the low quantity service. There is a minimum order charge of £22.29,  so I will probably order a couple of crystals for 4.59264MHz to give me a stable signal on 8.970kHz when divided by 512.  The company contact is Dave Hayes G4AKY 020 7100 6357.

Ultra-simple WSPR

G3XIZ has been having a lot of success on 40m WSPR recently using a 100mW DSB transmitter to generate a WSPR signal. All that is needed is an audio source (for the baseband WSPR signal), a balanced mixer and a PA. Of course, with this arrangement 3dB of power is lost in the "other" sideband which will appear outside of the WSPR sub-band. At some point - when I've got my lightbeam kit finished in January - I hope to try this arrangement on 28MHz WSPR. A very inexpensive 14.060MHz QRP frequency crystal will double to 28.120-28.130MHz so will be ideal to generate a 28MHz DSB WSPR signal at 28.1246MHz. Of course one could convert the TX into a phasing exciter and null out the other unwanted sideband. This should not be too difficult either as the phasing has only got to be good over just a 200Hz wide audio band, unlike speech which needs good phase balance over the full 300-2.4kHz band.

18 Dec 2011

15kW HF PA - definitely not for a QRP man!

A friend sent me this link http://www.dc9dz.de/en/index.html which shows the design and construction of a 15kW HF PA circuit for the amateur bands based around the Eimac 4CX10000D valve. Although I have no real interest in very high power and I do not expect to hear this on the air (please no!), it is a rather elegant piece of radio engineering.

17 Dec 2011

EU bureacracy threat to ham radio kit building?

The excellent Southgate Amateur Radio News site has some information which should concern amateurs who build kits. They recommend writing to your local MEP to make you views known.
"Thilo DL9KCE, reports a threat to amateur radio kits and modified equipment arising from changes to the EMC directive.  Currently amateur radio kits and modified equipment are specifically excluded from the directive but under the proposed changes they would be fully subjected to the EMC directive. The resulting high compliance costs could make it uneconomic to develop and sell kits so killing off the kit market. If radio amateurs wished to modify equipment it appears they would also incur additional costs and bureaucratic hassle."
The aim of the EU as a common market for trade is sensible but, like many here in the UK, I abhor it when the bureaucrats in Brussels start to interfere and try to fix things that are not broken. I don't want to get into a debate here about the merits of the Euro, but do feel that 2012 will be a year in which the citizens of Europe, and that includes the UK, will face some very tough decisions.