31 Dec 2009

New country on 500kHz - EI0CF -(IO65ih) 602kms

Just got a string of reports from Finbar EI0CF in Eire on 500kHz WSPR. He is in IO65ih some 602kms north west of me. This is my 9th country.

30 Dec 2009

New square and reporter on 500kHz

Just had a report from DK8ZJ on 500kHz WSPR from JO54ag at a distance of 685kms. This brings my total now to 51 unique reports on the band since I started in September 2009. Still just running 1mW ERP.

Conditions must be good as I've just had another report from  LA3EQ in JO28 at 769kms as well. I'll leave the WSPR beacon running overnight tonight.

Got my shack back

All the family apart from my wife Lis and our grandson Lucien have gone home after Christmas now, so I've got my shack back again and can do some evening operating and WSPRing. The 500kHz beacon is on at the moment and I'm getting decent reports from OR7T. I hear that Finbar EI0CF/GI4DPE is now getting active on 500kHz WSPR. If he is able to hear me - I hope so - this would be a 9th country.

27 Dec 2009

500kHz WSPR running today

The 500kHz WSPR beacon is running today but is unlikely to be on this week very much as we have our grandchildren coming to stay, so there will be a happy chaos about the place! Only M0LMH has spotted me so far this morning, at 223kms. Last night I got reports from G, GM, ON and DL.

26 Dec 2009

An eventful return home

Today we travelled back from our son's in Kent - and broke down TWICE. The car and battery were fine when we left but the car would not start after refilling with fuel. A jump start got us going again. Then on the M11 near Stansted we broke down again as the battery was hardly functioning and the engine was struggling. We came to a complete stop on the hard shoulder. Thankfully our Direct Line breakdown service towed us home.  A new battery will be bought on Monday and we'll see if that was the only fault.

25 Dec 2009

OK1VEN builds my SAQ converter - see his video

OK1VEN has been building a version of my SAQ converter which up-converts the 17.2kHz signal to HF. He produced a time-lapse video showing him building it, which he put onto YouTube recently. His version looks a lot neater than the G3XBM original!

See http://www.youtube.com/watch?v=x-Azk9wmIvg

Merry Christmas everyone

A very happy Christmas to everyone reading this blog. Whatever your circumstances, I hope the day is a peaceful and happy one. No ham operating here today as my wife and I are away from home at our younger son's home in Canterbury. Instead, we've been told to relax and keep out of the kitchen. Suits us!

23 Dec 2009

WSPR reporting - the REAL advantage

This evening, after a brief foray on 40m QRP CW, I returned to 500kHz WSPR whilst getting on with other jobs in the shack. As an example of just how good WSPR can be, see the example shown here in which one brief WSPR transmission results in no less than seven reports. In an instant I could see just where my 1mW ERP signal was getting and how well it was being received. Using modes like CW this sort of thing is just not possible. OK, it is beaconing and not a contact, but to be honest I'm more interested in testing my TX system, checking propagation, seeing how my antenna changes have affected things than having a "rubber stamp" HF QSO in which little information is being exchanged.

22 Dec 2009

40m CW with the Elecraft K1

This evening, for a change, I fired up my little Elecraft K1 4 band QRP CW transceiver that I built a few years ago. Not much doing on 20m or 30m so I went on 40m CW and worked a few stations around Europe. Worst report was 559 and the best 599. It was a change from 500kHz WSPR.

21 Dec 2009

Gnat 1 transceiver - anyone made/used one?

Has anyone here built and used a Gnat-1 single transistor transceiver? This was in SPRAT earlier this year and it was designed by Chris Trask N7ZWY. Although I've seen a few pages with photos of copies, I've not heard how well it works and what anyone has worked with one. The picture on the right is from LY3LP's website and shows his version for 20m.

Designing crystal oscillators

If you want a range "sure fire" crystal oscillator designs to suit fundamental and various overtone modes you should check out the "Oscillators" page on the QuartSLab website. This has details of circuit values and configurations that will really work. Most of these designs are ones I recognise from my days at Pye/Philips PMR, so I know they are reliable and well tried.


An ideal, if late, Christmas present is the latest Sprat CD which has all editions of this excellent UK QRP magazine from edition 1 to 140.  Price to members is £4 and to non-members £10 plus postage.

Starting work on the 10m transceiver today

The weather's a bit warmer (0 deg C) so I'm going to start on the local oscillator section of my DSB transceiver today. Will almost certainly use a mixer/VFO or mixer/VXO using a ceramic resonator instead of a crystal. This will allow me to cover a useful part of the band on either CW or sideband and to provide CW offset easily. The DSB modulator will be a matched pair of diodes.

Quote of the decade

"If the climate was a bank they would have saved it", said Venezuelan President Hugo Chavez. "But it is not. And they have not"

See http://news.bbc.co.uk/1/hi/sci/tech/8423822.stm

20 Dec 2009

Pre-Christmas snow - improved 500kHz?

In the East of England we have had a treat these last few days: deep (for us) snow that is crisp and beautiful. We've had about 10cms here with a little more last night and everywhere is a picture. The attached photo is the lane immediately behind my QTH. This is a video of my house from the road in the snow.

Not sure if it is the improved ground conductivity, but my signals on 500kHz have been reported stronger these last few days.

Sunspots for Christmas please Santa

Judging by the last few days we are definitely seeing much increased solar activity at last. Today the sunspot count was an astounding 43, a figure not seen in a VERY long time. Is it too much to hope for some decent F2 openings on the higher HF bands over the Christmas and New Year? Whatever happens in the short term, there is now a high likelihood of a decent improvement in 10m propagation in 2010. Whoopee!

See http://www.solen.info/solar prepared by Jan Alvestad.

19 Dec 2009

500kHz WSPR - when I forgot the ATU!

Having used my 5m long vertical on 40m to work OY9R on QRP SSB this afternoon, I went back onto 500kHz WSPR but completely forgot to connect the ATU, so the antenna was connected directly to the transverter with no matching at all! I only realised this when I got a report from M0BMU some 20dB below that normally received (at -26dB S/N). I've since reconnected the 500kHz ATU and the 500kHz signal is back to normal. The IRF510 survived the gross mismatch.

Climate change: Copenhagen fudge and disappointment

The climate change summit ended in a mess with nothing much of substance coming out of it. Let us hope that a legal binding international agreement can be forged next year, although I have my doubts. The full text of the agreement (can you call it that even?) is available for view.

Whatever your views on the reasons for  rising global temperatures, and the scientific evidence for man's influence on this is now overwhelming, we do need to take steps to put the breaks on further rises. My biggest worry is the risk of the tundra's permafrost melting releasing huge quantities of methane. This would make the CO2 problem seem like a walk in the park. If this happens we could be looking at human life in deep deep crisis. We MUST, and can, take steps to avoid this if the data is made clear to people and we take collective action.

18 Dec 2009

500kHz antenna video

As it was a nice snowy day I took a short video of the 500kHz spiral top loaded antenna that I use for my WSPR testing on the band. The spiral part is hard to see but consists of 8 turns of wire spiralling into the centre on top of the 5m vertical section. There is also a further brief video showing the end of a 500kHz WSPR transmission.

Uk 500kHz permits extended to 2012

Just seen this today on the LF reflector:
Ofcom has decided to extend the period of Notices of Variation (NoVs) to the licence for operation in the 501 to 504 kHz band until 29 February 2012. The maximum effective radiated power (e.r.p.) limit is maintained at 10 dBW (10 W).
Only another 40dB ERP to find then :-)

17 Dec 2009

Is WSPR a good thing?

There's a letter in Jan 2010 RadCom about the use of WSPR on 500kHz that advocates keeping the band just for CW. I understand the sentiment, but WSPR is a very narrow band mode taking just 6Hz bandwidth for a single transmission, which may be sent for as little as a few minutes in each hour. Surely there is space for both WSPR and CW? Incidentally I've had several attempts at CW QSOs with quite strong stations on the band and, with a few exceptions, it has been hard to get a contact with my low ERP.

Not so with WSPR as I can get reports (via the database) day and night in great detail - reporting station's callsign, S/N level, distance, QTH locator, direction. All data that confirms the signal has propagated to the distant receiver. It allows me to see in a few minutes the effect of a change of propagation, antenna, ground, power output etc.

Also, take another example (reported in an earlier blog entry) on 40m this week. Noise level here was running at S8-9 and it was a struggle to hear much on the band. I go on to WSPR (running 5W to my 5m long vertical) and get a report within a few minutes from VK4YEH who was 16451kms away. On CW I would never have heard him and I doubt he would have heard me. With WSPR I KNOW that my QRP signal reached Australia.

Like many, I enjoy CW especially with QRP, but there is definitely a place for WSPR on ALL bands as a real means of experimentation with propagation, antennas and rigs.

Views please?

Video of the G3XBM shack

Just for fun, I've put a very short video of the G3XBM operating "shack" (actually a corner of the smallest bedroom) onto YouTube. It shows the current set-up of homebrew and commercial equipment in use as well as the 500kHz transverter. I do most of my construction elsewhere.

16 Dec 2009

New 40m WSPR DX record (for me) - 16451kms

Just put my WSPR beacon on 40m a few minutes ago. First report was from a G station 44kms away. The next was from VK4YEH who was 16451kms away, a personal DX record with WSPR. Then in the following 30 minutes just G4AKU - I was lucky.

Sunspots - an improving picture

Sunspot group #11035 has grown into the largest and most magnetically complex sunspot group of solar cycle 24. At 0102 UTC the sunspot group released a small C5.3 solar flare, the largest solar flare of solar cycle 24.  The sunspot count is 38 which is the highest of solar cycle 24. The solar flux index is 82 which is tied for the highest SFI of solar cycle 24.
I've got to get back on 10m in readiness for the good times ahead. Roll on 2010!

Idea for a simple 10m WSPR transceiver

GQRP club sells  inexpensive 14.060MHz crystals and these doubled would come out on 28.120MHz. I am wondering if they will pull UP to 28.1246? If so, they would make a perfect source for a DSB WSPR transceiver. Half the TX power would be wasted on a signal 3kHz lower but it would be a very simple design with just an oscillator, doubler, balanced mixer, PA and low pass filter, plus the basic audio input and DC receiver parts, which would re-use much of the TX design. Some experiments are needed!

Alternatively, can anyone suggest a more modern approach such as using a programmable reference oscillator as used in SDRs? What is the best one? Where do I get them from?

15 Dec 2009

Linux Journal - special ham radio edition

The January 2010 edition of this US Linux OS magazine is a special one dedicated to amateur radio. Although I'm not a Linux freak, I'm sure that many readers will find it of interest.

See http://www.linuxjournal.com/ham

500kHz transverter boxed at last

Today I completed the 500kHz transverter by putting it in a small Maplin's ABS case with coax connectors and an on/off switch. Attached is a photo showing the transverter unit on the shack table and with the box lid open so you can see the completed unit. It has been a most enjoyable project. The schematic of the transverter is on my website on the "Operating on 500kHz" page.

On WSPR, I'm still awaiting my 50th unique report that I hope will come in the next few days before I take down the 500kHz antenna and reinstall my 28MHz halo.

13 Dec 2009

Big Ben - a 119 year old recording

Not ham radio, but just spotted this fascinating recording of Big Ben chiming. It was made on a wax disc 119 years ago in 1890.

Geminids meteor shower tonight

This evening the Geminids meteor shower should peak between 2000 and 2200z in the UK.  As there is no moon visible and the sky should be reasonably clear it could be a fine sight. Increased meteor activity should allow European DX on bands like 50MHz and 144MHz by meteor scatter (MS). Best place to listen/look is on 50.230MHz in JT6m mode.

YO5OFJ's pages with everything

Vanyi's Homemade/homebrew HF transceivers page is a collection of lots and lots of circuit ideas showing transceivers from 160m - 10m created by various people over the years. It is a good place to look for ideas when thinking about new projects.

DSB mod for the Heathkit HW8

When looking around for ideas for DSB rigs I found a page which shows how to modify the HW8 for DSB operation by adding a balanced modulator and audio stages.  KL7R reports that he worked New Zealand using the modified HW8 on sideband.

12 Dec 2009

Received in Norway on 500kHz

Last night, a couple of LA stations were listening on 500kHz WSPR. Neither had heard my 1mW QRP signal by 2300z, so I left the station running through the night. At 0418z LA9BEA heard my signal at -28dB S/N in JO29 square some 836kms to the north east of me. This is now my 8th country, and 49th station, to log me on the band.

11 Dec 2009

NMRevue Magazine (from Belgium)

Just found a link which takes you to back numbers of the NMRevue magazine from Belgium. I'm not sure if this is a club/regional magazine or a national magazine, but it does have quite a few nice constructional articles in each issue. Unfortunately you will need to read French to fully enjoy this.

Rising sea levels - what would happen?

Whatever your views on the causes of climate change, it is a FACT that the Earth is currently warming and sea levels are rising. This interactive map allows you to put in the likely sea level rise, in 1m steps, to see how the coastline would change. Some places are little changed but others are e.g. The Netherlands and the Fens in the UK.

A draft text for an agreement on climate change reduction has been released today in Copenhagen. It needs a lot of work.

10 Dec 2009

Classic 10m DSB TX

There was an article, in 73 Magazine back in the early 1970s, about a simple crystal controlled, 1W 10m DSB transmitter. This was reprinted in a Dutch magazine and in RadCom. The schematic had at least one error (one diode in the mixer wrong way around, that I have corrected here), but it is a useful "ideas" starting point for a DSB transceiver. This circuit used PNP transistors. Today I'd use NPN 2N3904 devices and T37-6 toroids everywhere.

ON/F6CNI on 500kHz

This evening, conditions have been very good on 500kHz with almost continuous reports from GM4SLV up in the Shetland Is 896kms to the north. Also tonight, a new reporter ON/F6CNI in JO20 square at 424kms. His reports were very strong (-2dB S/N). This brings my total to 48 unique reports on 500kHz WSPR.  Tonight I've been using the new version of the transverter on the small, tidy, board (see picture on earlier blog entry today). This should be boxed tomorrow.

SAQ (17.2kHz VLF) reception

This link takes you to a recording of SAQ on 17.2kHz as heard by M0LMH in IO93 square.  It is quite strong when the signal starts. I listened on the Dutch online SDR and SAQ was not as strong there as I would have expected at 1600z. This is a recording of SAQ in Connecticut USA made by Jay W1VD earlier today.

Netherlands to get 500kHz

Full licence amateurs in The Netherlands can opt for an experimental permit to conduct experiments in the band 501-504 kHz with a maximum power of 5 W EIRP and a maximum bandwitdth of 100 Hz. The experiments will start on 1 January 2010 and will continue for one year maximum. News came via Rik OR7T and the RSGB LF reflector.

500kHz transverter rebuilt (and working)

This morning I rebuilt the 500kHz transverter in readiness for putting it in a small case. It fits comfortably on a 4 inch by 3 inch single sided piece of copper laminate built "ugly style". The unit worked first time and it has already received 4 WSPR spots from G3ZJO at lunchtime today.  The car keys give some idea of how small this unit is.

SAQ (17.2kHz) - on line receiver

Dec 10th the transmitter at SAQ (Sweden) on 17.2kHz is transmitting a special CW message. Also there is a transmission on Dec 24th. An on-line SDR in The Netherlands that can be used to listen to this. See  http://websdr.pa3weg.nl/ .  Alternatively, try listening with a simple up-converter or simple VLF receiver. 
Extra transmission on 10th December
In order to celebrate the 100th anniversary of the Nobel Prize to
Guglielmo Marconi and Karl Ferdinand Braun, we plan to be on air on 10th December at 08.00 UTC and 16.00 UTC. No reports are required and no QSL-cards will be given.

Traditional transmission on Christmas Eve 24th December
SAQ will be on air on 24th December at 08.00 UTC. The frequency is as usual 17.2 kHz CW. Reports are welcome and will be confirmed by QSL-cards.

9 Dec 2009

Latest sunspot predictions (from NOAA)

The very latest table of predicted sunspot numbers for cycle 24 have just been published on the NOAA website. They show a peak of 90 (+/-10) in May 2013. According to the table, the sunspot count will have risen to 45 by this time next year, so we should be assured of some regular USA contacts on 10m next autumn.

500kHz transverter (breadboard) photo

This is a photo of the 5W 500kHz transverter breadboard in its "raw" state. In the next couple of days it will be rebuilt tidily into a small aluminium project box and should look a lot neater. Still, isn't it amazing that something this rough on the bench top can work so well and be heard 951kms away!

Power harvesting IC - runs off 20mV produces 5V

This week's Electronics Weekly has a link to Linear Technologies new power converter IC (LTC3108) that can run from 20mV and deliver 5V. It is designed to be used with Peltier effect devices and similar sources of low voltages, but it could be used with the DC power derived from a crystal set.

Weather and 500kHz antenna matching

It surprises me how much my antenna matching changes depending on weather, temperature etc. I use my simple ferrite rod ATU for the main antenna tuning (tapping down the coil for best antenna and TX connection but I make final adjustments using my little Elecraft auto-ATU at the shack end of the feed coax to the remote ATU in the back bedroom near the antenna. If it rains or the weather is cold, I need to rematch the T1 ATU to get best SWR.  I guess this is all due to the ground losses changing in wet weather as a result of changes in soil conductivity.

8 Dec 2009

A new report from Germany on 500kHz

Last night I was copied, just, at -30dB S/N, by Veit DL7ET in JO31 square at 468kms. This is now my 47th unique station report on the band (well 49 if you include 2 CW contacts). At some point soon the antenna for 500kHz will have to come down so I can re-erect my 28MHz antenna, but maybe not for a couple more weeks.

The next QRP project?

Having finished the 500kHz transverter to my satisfaction I'm mulling over the next project "big idea" to keep me amused on a winter afternoon. I do want to build some homebrew gear for 28MHz as this remains one of my favourite bands: antennas are small and unobtrusive, DX is not hard to work with QRP when the band is in good shape, and the frequency is low enough to be able to make gear, and get it working, with my limited test equipment. Maybe I should do it in stages:
  1. A direct conversion mixer and back end with CW/SSB filter bandwidths.
  2. A direct-conversion 28MHz front end mixer and RF filter based on an SBL1 or NE612/602.
  3. A stable mixer-VFO covering the CW and SSB part of the band.
  4. A driver and PA for up to 5W.
  5. A DSB mixer module to use with the above to use in a simple DSB transceiver.

Scottish DX on 500kHz

After no luck on CW I returned to 500kHz WSPR and was immediately rewarded with 3 spots including one from GM4PMK in the west of Scotland in IO66 square some 615kms to the north west of me. He's spotted me before but this is my first report from him in several weeks. He is reporting Andy G4JNT some 20dB stronger than me, which is consistent with the difference in ERP (Andy is running 200mW ERP and I am running around 1mW ERP).

500kHz CW activity tonight

Several DX stations on tonight on 500kHz CW. OR7T was calling LA3EQ (recently allocated the band in LA) and OZ8NJ was a good signal working G3DXZ. So far tonight, with all this excitment, no-one has heard my 1mW ERP signal on the key! WSPR is much easier!

7 Dec 2009

500kHz full transceive transverter with 5 extra parts only ..and no relays!

I've now modified my WSPR tx up-converter to a full TX/RX tranverter suitable for WSPR, QRSS and CW  in a very simple way, making use of the FT817 split facility which allows you to RX on 500kHz and TX on 28MHz. By adding a series LC between the TX PA and the FT817 input/output RF connection (with back-to-back diodes at the L and C junction, this allows "pass through" from the 500kHz ATU to the FT817 on RX (tuned to 500kHz). On TX, the diodes conduct and the C part is in parallel with the first cap in the TX low pass filter. This scheme is now working really well with good RX sensitivity and no change in TX power out.

5 Dec 2009

500kHz WSPR summary (1-2mW ERP or less)

After about 3 months on 500kHz WSPR, I've now been decoded by 44 different stations in 19 grid squares in 7 countries with best DX still SM6BHZ at 951kms.

Today I got some reports from Sam G4DDK, better known for his RadCom microwaves column - nice to see him listening on 500kHz.

10m/40m WSPR

This afternoon, for a change, I've been putting out a signal on 10m WSPR as my vertical on 500kHz can be resonated on 28MHz using the Elecraft auto-ATU. So far nothing heard here and no reports.

All was quiet so I moved to 40m where instant reports at 5W, then 500mW, from all over Europe. Now testing at 50mW output.

3 Dec 2009

New grid square and station report on 500kHz

Just got my first WSPR report from Brittany, France from F5JNV in IN98 square at 427kms. This is now my 41st report so far on 500kHz. A 42nd report was received from a G SWL a few minutes later.

SAQ (17.2kHz): extra transmission Dec 10th 2009

There will be a CW transmission with the Alexanderson alternator at SAQ on 17.2 kHz on Dec 10th 2009 at 08:00 UTC and again at 16:00 UTC the same day.

The reason for the extra transmission is a centenary commemoration of the Nobel Prize given to Guglielmo Marconi and Karl Ferdinand Brown. SAQ does not want QSL-reports this time and will not verify. They still intend to continue with their annual transmissions on Christmas Eve (morning), Dec 24, at 08:00 UTC with tuning up from 07:30 UTC.

This is always a great opportunity to try your hand at VLF CW reception either with a simple up-converter, direct conversion RX or even a software receiver totally implemented on a PC.

2 Dec 2009

Back on 500kHz WSPR (TX)

Having just got some more IRF510 FETs from the GQRP club I've rebuilt my 500kHz PA and got it working properly towards class E. As long as the antenna is close to 50 ohms the PA hardly gets warm (on a WSPR TX cycle at 5W RF from the PA) as the efficiency is now so good.

Will run the 500kHz WSPR beacon overnight tonight then plan to modify the PA and ATU to 136kHz for a few days. 136kHz WSPR tests will run over the weekend if things go to plan. ERP will be even lower than on 500kHz, but I'm hopeful of some reports. If you get a chance to listen and report (via the WSPR database) I'd be most grateful.

The new TX PA is working well: I've had a 0dB S/N WSPR report from F6CNI near Paris!