Sunspot count - 51

Just seen the sunspot number - 51. Things are looking up. If anything, I think that the rate of improvement in sunspot activity is slightly ahead of predictions. Maybe we'll have a bumper cycle 24 peak after all. Only time will tell.

Update: the count today is a staggering 71!!

VK2ZAY's version of the XBM80-2 transceiver

A few more people have been making the XBM80-2 transceiver. One is Alan Yates VK2ZAY who has made a de-luxe version with some refinements and additions. See it on his blog at http://www.vk2zay.net/article/238

Problem with Sprint Layout 4 PCB package

Trying to do a small PCB for the XBM80-2 80m micro-transceiver using the Sprint Layout 4 PCB layout package I hit a problem: wanting to use a single sided PCB for low cost I did a groundplane fill. Then I wanted to connect certain pads to this. I cannot see how to do this! Several people have offered advice, but nothing seems to work: any attempt just results in a new clearance area being created. In the end I gave up and filled in the ground as another track and join it to the pads manually. The resultant draft PCB (1 inch square)  is shown here. I have not built it on a PCB yet, so this is only a suggestion. An SMT version could be half the size - i.e. VERY tiny indeed.

XBM80-2 video and PCB (draft)

A short video about the XBM80-2 80m CW micro-transceiver. This is built "ugly style" on a piece of copper clad board. It will get put in a box soon! I've also been having a go at a PCB (just 1 inch square - 25mm x 25mm).

Back on 500kHz tonight

Having been playing around with the XBM80-2 80m micro transceiver for a couple of days, I've not been on 500kHz for a bit. However, I am back again tonight with the 1mW ERP WSPR beacon. Reports from LA3EQ and GM4SLV amongst others received so far.

Prosperity without Growth?

Prosperity without Growth? - The transition to a sustainable economy is a freely downloadable publication from the UK's Sustainable Development Commission. The report calls on world leaders to adopt a 12-step plan to make the transitionto a fair, sustainable, low-carbon economy.

Improvements to the XBM80-2 80m QRP transceiver

A few small value optimisations have improved the XBM80-2 transceiver. I've optimised the collector circuit values and this has resulted in 120mW output (was 60mW) from a 12V supply. The sensitivity is a little higher, the backwave level is lower, the amount of AM breakthrough from medium wave broadcasters is lower. At 4pm I was hearing DR2010O in the Ruhr area of Germany working all over Europe and could copy almost all the stations that he was working but I failed to break the pileup with 120mW. I'm beginning to think this little transceiver could be really useful. There is no reason why it should not work well on any band up to 28MHz (with less output) with a fundamental crystal. I'm wondering how it will perform on 50MHz with the collector tuned to x2 crystal?

XBM80-2 heard at 430kms

This evening I tried listening for my 60mW CW signal from my XBM80-2 80m micro-transceiver on the on-line SDR at Twente in Holland. The signal was clearly audible at RST529 when I keyed the transmitter slowly! Distance is 430kms (267miles).

Another XBM80-2 QSO tonight

This evening I worked G6ALB 3kms away on the XBM80-2 60mW ultra-simple 80m transceiver getting a 599 report. Andrew was copied at 599 when he was using his 300mW TR6C4 simple valve transceiver which has a regen RX. Andrew also sent test transmissions using his signal generator and I was able to copy his signal when he was running 3mW output. So, the conclusion is, as AA1TJ has already proven, the design is quite a useful one and VERY simple.

Good 500kHz DX overnight with 1mW ERP

For the first time in more than a week I ran the WSPR beacon through the night. Best DX reports were from GM4SLV, GM0UDL and Lubos OK2BVG at 1232kms. Lubos sent me this picture of his fine shack. Notice the lovely LF/MF loading coil on the left hand side and the LF receiving loop in the corner. Lubos has a very nice collection of equipment. He has now managed to receive me on several different occasions on 500kHz.

More new ones on 500kHz

A new station has reported my 500kHz WSPR signal this evening: ON4BB in JO21 at 294kms. Later, GM0UDL spotted me from up in IO77 square at 659kms, bringing the total unique WSPR reports up to 76.

AA1TJ's success with the XBM80-2

Mike Rainey AA1TJ has built his version of the XBM80-2, but LESS the audio stage, using instead his 600 ohm magnetic headphones via a transformer, and has managed some QSOs well over 100 miles. He changed the emitter resistor to 15k to reduce the signal radiated on key-up (backwave) as well as made a link coupled bandpass filter output/input circuit. This would reduce the amount of AM breakthrough usefully.

76th unique signal report on 500kHz with 1mW (or less) QRP

This evening, I was WSPR decoded by a new station in the Netherlands PI4Z in JO11wm at 260kms. This brings the total number of stations who have sent me reports on the band to 76 now (72 via the WSPR database, 2 emailed WSPR reports and 2 CW stations) in a total of 10 countries. Best DX report still 1232kms.

CQ-PA article on 500kHz

The Dutch magazine CQ-PA has quite a large article on 500kHz operation this month. I was very pleased to see my little IRF510 based transverter circuit and my small vertical antenna were shown. Amateurs in the Netherlands have recently been granted access to this band.

Nuclear Fusion breakthrough?

Some recent research may have helped the dream of unlimited and pollution-free energy from nuclear fusion become a big step closer. Scientists in the USA have demonstrated that containment of atoms for fusion using laser beams is far less problematic than first thought. Unlike current nuclear fission, nuclear fusion reactions create no radioactive waste materials. Potentially nuclear fusion reactors, if created on a commercial scale, could dramatically help supply clean energy the world so badly needs. See http://news.bbc.co.uk/1/hi/sci/tech/8485669.stm

Super-efficient VHF antenna?

See http://www.nist.gov/public_affairs/techbeat/tb2010_0126.htm#antenna

"The National Institute of Standards and Technology (NIST) and partners from industry and academia have designed and tested experimental antennas that are highly efficient and yet a fraction of the size of standard antenna systems with comparable properties. .....NIST engineers are working with scientists from the University of Arizona (Tucson) and Boeing Research & Technology (Seattle, Wash.) to design antennas incorporating metamaterials—materials engineered with novel, often microscopic, structures to produce unusual properties. The new antennas radiate as much as 95 percent of an input radio signal and yet defy normal design parameters."

Mosquito single IRF510 transceiver

EA3GHS and EA3FXF have produced a single IRF510 FET based version of his Mosquito transceiver using a PC as the back end of a software defined radio (SDR). In essence, the FET is used as a regenerative or direct conversion receiver - I think the two are indestinguishable in a single stage RX - with audio coupled to the sound card via a mains transformer which steps up the impedance. The IRF510 is capable of up to about 7W in this application. Coupled with an SDR back-end and this is SOME simple transceiver, especially if the crystal is VXOed.

Web based HF receivers (SDRs)

Web software defined receivers (SDRs) are becoming quite common now. They allow you to eavesdrop on a number of different HF bands and tune around for stations as if you're located at the distant location. The best place to find a list of these receivers is at http://www.websdr.org/ . I have used the one in Twente, Holland to see if my QRP 80m signal got to The Netherlands (it did) and to check activity on bands like 500kHz. Sometimes these SDRs are located in places where the background noise levels are very low too.

Apple iPad tablet launched

Apple has finally revealed its new killer product - the iPad. My son has an iPhone and is very pleased with it. I doubt I will be persuaded to buy either. I have been tempted with the Apple iPod Touch which is a very desirable product.

500kHz again tonight

After a break of a couple of days, I'm back on 500kHz WSPR again this evening with my 1mW ERP. The reports are still coming in from far and wide (G, GM, PA and LA so far), although no super-DX from central Europe yet this evening.

Walford Kits "Fivehead" SSB transceiver

A friend of mine is building a Walford Kit "Fivehead" SSB transceiver. He has got the kit, but was surprised to find the parts placement was not silk screened on the PCB; I guess this is a cost saving measure.

Although there is a not-to-scale layout, a clear colour photo from above of the assembled board from the component side would help him a lot. He's asking Tim if he has one he could email, but does anyone already have one they could email me please?

XBM80-2: a 2-way QSO and report

This morning I worked M0DRK using my tiny 60mW XBM80-2 transceiver I designed last week. It uses just 13 parts plus the crystal, earpiece and optional frequency offset switch. My report for Derek was 599 and he gave me 599+40dB. Derek is in the same village. Also monitoring was G4LHI in Huntingdon 32kms away and he reported my signal was as strong as Derek who was running 5W.  In fact 60mW is only going to be about 3 S points down on 5W. I also heard GM3JUD when listening on the XBM80-2 on 3.560, but was unable to raise him.

Shortwave in the 1960s - interval signals montage

Yesterday I found this wonderful link which is a montage of 40 different old shortwave interval signals from almost 50 years ago. Get a coffee, sit back and listen.  Imagine you are listening on your one valve radio in your bedroom in 1964.  It brings back such happy memories that I am almost tearful with nostalgia.

http://garlinger.com/QSL/montage.mp3

G3ZJO in QRSS3 on 500kHz

G3ZJO has a QRSS3 beacon sending in FSK built in Altoids tins and running QRPp power. This is is a screenshot (from Spectran) of his signal this afternoon. I have superimposed his callsign, which is clearly visible on the upper line. The first dash of the G in his call is missing in my capture.

Simple 80m CW transceiver

Want to try something really simple?  I am now waiting to have a QSO on 80m CW using my XBM80-2 transceiver that I put together in the week. Pout is 60mW. The only switching between TX and RX is by the morse key. Additional offset can be had with the switch in series with the crystal. Skeds with local stations are being arranged.

ERP on 500kHz (part 2)

Yesterday I did a recalculation of the G3XBM ERP based on the classic formula and re-measurements of my antenna current. My antenna is a 5m long vertical with a spiral top hat of about 7 turns about 1.5m x 1.5m. Not being clear how to model the top hat I assumed effective heights of 5, 4 or 3m. The measured antenna current is 0.12A. My results are as follows:

Assumed effective height 5m     ERP = 1.53mW
Assumed effective height 4m     ERP = 0.98mW
Assumed effective height 3m     ERP = 0.55mW

So, I believe my 1mW ERP previously calculated is not a bad estimate, and it may indeed be lower than this figure.

Rik ON7YD (OR7T) has just sent me this email:

"I simulated the antenna based on your description (with MMANA) and the current through the vertical wire seems to be quite constant. So the tophat works well and the effective height will be more or less the physical height. The simulation gives a radiation resistance of 0.074 Ohm, so with 0.12 A a radiated power just over 1mW EMRP (1.75mW ERP). In the real world it will be some dB's less (as Jim stated recently), probably something like 0,5 to 1mW ERP.  Very impressive that it covers over 1200km."

JT4A mode on 500kHz

The next (operational) project is emerging from the mists..... Several people have started to experiment with JT4A WSJT mode on 500kHz. This allows basic EME/MS style QSO exchanges so should allow me some 2-way contacts on the band with my low ERP. Still to work out how to run the software though: when I tried the other night I could see strong traces but no decodes. Getting this sorted will be half the fun. Then I might try to mode on VHF too. JT4A uses a bandwidth of 17.5Hz with tone spacings of 4.375Hz and can decode down to -23dB S/N. This is somewhat less sensitive than WSPR but would still allow QSOs with quite a large number of the stations who've heard me on WSPR.

QRP Books

International QRP Collection is a new book bringing together articles from magazines around the world on QRP (low power) radio. There are articles on commercial equipment, homebrew ideas, test equipment and operating on bands from 160m to microwaves plus much more. A friend who is not too familiar with QRP thinks it is a good introduction, but I must admit I was disappointed: the collection seems disjointed and, in my view, a better set of articles could have been put together. As an example, the intriguing transceiver on the cover does not appear in the articles inside! Overall, I'd give this one 6 out of 10. The book is available from the RSGB. 

QRP Basics by G.Dobbs G3RJV is a much better book and worth buying.

The Pixie Files

The Pixie and Micro80 are  well known simple transceivers for any HF bands. I've built both in the past and they do work well considering their lack of complexity. The main limitation is the receiver which uses the TX PA as a simple mixer. For those wanting more information on the Pixie and its derivatives check out The Pixie Files which is a collection of articles from SPRAT.

ERP calculation on 500kHz

I've recalculated my ERP based on a better measurement of antenna current. I was using a dust iron core for my current transformer, so swapped this for an FT37 ferrite toroid today and got a lot more current measured now. My antenna current is actually around 0.12A. My antenna is 5m long with a small spiral top so the effective height must be <5m. Even putting in 5m into the classic formula I cannot make my ERP exceed 1mW. I make it more like 600uW. Interestingly this is 20dB more than the original estimate from M0BMU and since then I'd increased the ERP, I believe, by around 20dB which would also make it 600uW. Of course the margins of error must be large.

The Internet in the 19th Century

Yes, the internet was alive in the second half of the 1800s, albeit in a rather more limited form. It was possible to find out information from right across the world in a matter of minutes as long ago as the 1860s by using the very extensive telegraph network that ballooned across the globe within a few decades. There is a fascinating book all about this that I can highly recommend called The Victorian Internet by Tom Standage which is available via Amazon and other booksellers. If you thought it was the coming of wireless that connected the world then think again.

More DX again tonight on 500kHz: 1232kms

Lubos OK2BVG is receiving me well again tonight on 500kHz WSPR. In the last hour two reports received via the database.

500kHz DX with 200uW ERP

Guess what?  Lubos OK2BVG has just spotted G3ZJO's tiny signal on 500kHz. Eddie is running only 200uW ERP. This evening conditions on 500kHz have been truly superb.

Done it at last! 1232 km on 500kHz

This evening, my target of exceeding 1000kms on 500kHz has been exceeded by a great margin. Lubos OK2BVG in JN88ks managed to hear my 1mW ERP signal at a distance of 1232kms. This is by far my best DX and a new country on the band using WSPR. Lubos even moved to his quieter country QTH in order to hear my weak signal. I am SO pleased he has such good ears! This was his message half an hour ago:

Hello Roger, LF!
This moment is just now:
2136  -7  0.2   0.503874  0 G4JNT IO90 23
2142 -29 -0.5   0.503910  1 G3XBM JO02

Congratulation!
Lubos, OK2BVG, JN88KS

A little later the signal was even stronger:
2206 -24 -0.6   0.503903  0 G3XBM JO02 0

K4TWJ - silent key

Dave Ingram, K4TWJ died this morning having lost his battle to overcome a massive heart attack on New Year's Eve. He wrote a regular column in CQ Magazine and was well known in the QRP community. RIP Dave.

10m WSPR reports from Germany

This afternoon I've been WSPRing on 10m with either 2 or 5W output to my 5m vertical antenna tuned via the Elecraft T1 ATU. Most spots have been from G4IKZ who is quite local, but I then had 4 spots from Germany including DK6MK in JN68. Even the briefest of openings is noticed using WSPR.

500kHz monitoring by OK2BVG

This email came in today from Lubos OK2BVG who is going to extraordinary lengths to help me meet my 1000kms target on 500kHz WSPR. I do hope he hears me from a quieter country QTH. Last night my best DX was 960kms.

Hello Roger!

I didn´t see your QRPP signal, when we tried WSPR some days ago.  So... I packed my receiver + computer to a car and I moved them on my portable QTH outside of town today morning. I have got EWE aerial for 500kHz there. I started whole set on frequency 502.400kHz. It will be receiving continuously some days and nights. I have got Internet line from my cottage to my home hamshack, so I am able to see what is written in WSPR window there. It will be interesting test, I think.

73! Lubos, OK2BVG, JN88KS

Plessey reborn as UK's newest semiconductor firm

Many of us remember the Plessey name from the range of RF ICs it made back in the 1980s e.g. the SL640, SL641 and the SL6440. In their day they were ahead of the time. Many an SSB transceiver was built around these ICs. Well, Electronics Weekly reports Plessey is back.

"Plessey Semiconductors, one of the most renowned names in the UK’s semiconductor history, has been relaunched as a chip business operating from the original Plessey CMOS fab at Roborough in Plymouth.
Plessey Semiconductors has been created out of Plus Semi, a company set up to acquire the manufacturing facilities of two former Plessey fabs in Swindon and Roborough."

Electronics Weekly is available online and is well worth checking.

Solar Flare and Aurora

Yesterday, satellites picked up the strongest solar flare in almost 2 years. The M2 class eruption came from an old sunspot (number 1039) behind the sun's eastern limb. There is a chance of HF blackouts and auroral conditions today Jan 20th. See http://spaceweather.com/

Overnight 500kHz WSPR tonight

For one of the last times this winter, I'm going to leave the 500kHz WSPR beacon running through the night. Beating the 1000kms barrier seems to be limited not by my low 1mW ERP, but by the absence of stations in the 1000-1200kms range staying active through the night when conditions are quieter. So, a few more tries before I say enough is enough.

If you have a well equipped 500kHz WSPR station in Poland, Sweden, Austria, Czech Republic or at a similar distance from England please leave your RX running for the next few nights and keep a close watch for G3XBM around 503.900kHz +/-20Hz.