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!

28 Nov 2009

RXing on 500kHz this evening

Although I cannot TX on 500kHz at the moment (should be back on next week), I am listening again this evening and hoping to copy G3ZJO who is testing his station on WSPR. Not heard him yet but will keep listening.

26 Nov 2009

Off 500kHz TX for a few days

Our little 2 year old grandson has come to stay for a few days, so I'm unlikely to get much operating time until Sunday evening. I have to rebuild my PA before I can get back onto 500kHz TX, so it may well be next week before I'm on the band again. I shall try to listen as and when I am able. The main information I've gathered on FET PAs (especially in class D/E) for 500kHz is to make sure the antenna is well matched (i.e. don't adjust the ATU/matching when the PA is on), don't exceed the peak voltage rating on spikes, ensure that parasitic oscillations are well suppressed and be generous with the heatsinking.

24 Nov 2009

Another oscillator calculator

Harry Lythall SM0VPO has a most interesting site full of ideas. Among the useful stuff is an oscillator calculator which allows you to work out values of L and C to make an oscillator that Harry claims always works. The circuit produces about 20mW.

This is the link http://web.telia.com/~u85920178/blocks/osc7m00.htm

23 Nov 2009

500kHz WSPR - back to 100uW ERP

Having blown my 3rd IRF510 PA because of overheating, I decided to go back to my 700mW PA based on a 2N3906/2N3904 pair until I rebuild the transverter with a decent heatsink. This PA is bullet proof!  Having made antenna improvements since I last ran this ERP, it will be interesting to see what reports I now get. So far, just M0BMU and G7NKS at -10dB on the reports when running 1-2mW, so all is as expected.

21 Nov 2009


The following is an extract from a posting on the LF reflector and may suggest getting QRPp DXCC may have become a whole lot easier:
"The discussion at the RSGB meeting noted the ARRL’s position that essentially if two stations make WSPR reports with each other and this is confirmed by QSL or some other approved method then there has been a two way exchange of call sign, report and other info e.g. locator and that qualifies as a QSO for DXCC purposes."
This may surprise some, and did me.

Does anyone know precisely what the ARRL has said regarding DXCC qualification and WSPR? By the definition above I "worked" VK6POP with a few watts of WSPR on 40m earlier this week.

As someone pointed out, a lot LESS data is exchanged in an HF contest, when often the callsigns are not sent (very often) and reports are meaningless. At least with WSPR you get the full calls, location and QTH locators exchanged.

20 Nov 2009

Blown my 500kHz PA ......again

My IRF510 500kHz PA has a tiny heatsink (soon to be addressed when a new heatsink arrives) and it is not very tolerant of poor antenna match. As a result it died again this evening in mid WSPR! This afternoon I managed to raise to PA output to 8W by changing values and this must have made the tiny heatsink just too small to be useable. I also need to find a better way of getting my antenna tuned to 50 ohms.  This is all a good excuse to do a proper rebuild next week.

Belgium gets 4m allocation

With immediate start all radio amateurs in Belgium holding a full licence have access to 69.950MHz (+/- 5kHz) with 10W EIRP on a non-interference basis.  If you can read French or Dutch there is more information here.

19 Nov 2009

New WSPR DX record tonight (40m)

Trying out WSPR2 on 40m this evening and just got a report from VK6POP at 14465kms, which is a new DX record for me. I was running 5W to my 500kHz antenna tuned via the Elecraft T1 ATU. It must work pretty well on 40m!

First experience with WSPR 2 (new version)

Well, it works. I deleted the old version from my PC and installed V2 tonight. Set-up was straightforward and I like the slider to set the TX percentage. Also 500kHz is now one of the default listed bands (600m). My first TX was spotted (with the new version) by I2IAL on 40m.

WSPR 2.0 now available

WSPR 2.0 introduces a number of new features including a  user-friendly setup screen with drop-down selection of audio devices and rig-control parameters, support for compound callsigns, fine selection of the fractional time for transmitting, and a Tune button.  A new Advanced setup screen offers optional CW identification and tools for frequency calibration and automated frequency corrections for your radio.  Full details are presented in the WSPR 2.0 User's Guide, which you will need to read in order to use the new features.  For the first time, a binary installation package is made available for Ubuntu Linux (versions 8.10 and later), Debian 5.03, and other Debian-based 32-bit Linux distributions.

WSPR available at http://physics.princeton.edu/pulsar/K1JT/wspr.html 

Sunspots - blimey!

Just seen the sunspot count for today - 29 - which is pretty good for where we are in the new cycle. It is very clear that sunspot cycle 24 has got into gear and next year should show considerable improvement on bands like 10m.


It was my elder grandson's 2nd birthday last week. We went to Paris to enjoy it with his French grandparents and had a good time. This is a picture of both grandchildren when they came to stay a few weeks ago. It is my wife's birthday next week, so I'd better get thinking. Mine, just before Christmas, is easy as I tell my XYL what I want - usually some radio books.

500kHz PA blown - my fault

My IRF510 500kHz PA just died on me as I TXed for a full WSPR slot into an open circuit (the wrong coax connected!). It won't take 5 minutes to fix tomorrow, but this evening I'll WSPR on some HF frequencies for a change.

18 Nov 2009

500kHz - USA reception this evening

The 5W ERP beacon of W17XSH (the "WSPR shortened" call of WD2XSH/17) was copied here very well just after midnight. This is my first transatlantic WSPR reception and only my second 500kHz station heard from N.America.

Overnight my 500kHz WSPR beacon was running but no new stations reporting me when I checked at 0700z.

17 Nov 2009

8th country on 500kHz WSPR

Just got my first report from Wales tonight with a huge (for me) -6dB S/N report from GW3UCJ in IO81 at 286kms away.  Also a new reporter from Belgium ON6EO. Reports are very good tonight so the WSPR beacon will run overnight.

136kHz WSPR tests (soon)

Very encouraged by my results at 500kHz, I'd like to try some "low ERP" WSPR tests on 136kHz using the same small antenna and transverter (slightly modified).  Ideally I'd need stations like M0BMU, M0FMT, G7NKS and others not too far away from JO02dg to TX and to listen out for me, as these stations get a good signal from me on 500kHz.

Please would you let me know if you'd be able to listen and upload 136kHz WSPR spots sometime in the next week or so
? As yet I am not quite ready to start, but I'll let you know when I am.

15 Nov 2009

Presentation on CW and other weak signal modes

Andy Talbot G4JNT has put an interesting presentation about weak signal modes onto his website. He gave this talk at a recent Microwave Round Table. See http://g4jnt.com/MartleSham.htm. It is exploring how we can push the boundaries further when working with very weak signals.

My first 2-way CW QSOs on 500kHz

This afternoon, just after midday, I worked Mal, G3KEV, in Scarborough for my first 2-way CW QSO on 500kHz. I gave him 569 and he gave me 529. Then at 4pm I was called by Chris G3XIZ who gave me 579. ERP at my end around 2mW.

14 Nov 2009

Report from 7th country on 500kHz

This evening I got my first report from Germany on 500kHz WSPR - DK6NI in JN59ln at 805kms. This brings my countries total to 7 now.

FT817 successor coming?

Has anyone heard any intelligence/news on what is happening at Yaesu regarding new hand-held all-band, all-mode, successor to the FT817 with new features such as internal auto-ATU, speech processor, maybe 70MHz included on EU version, LiIon battery pack, etc...

Transatlantic 500kHz reception - VX9MRC

This evening at around 2200z I heard my first ever North American ham station on 500kHz. VX9MRC, the beacon operated by VO1NA was coming through on CW (about 10wpm) on 507.77kHz in and out of the noise at about RST339 at best. On WSPR he would have been solid copy.

A 30th reporter on 500kHz

Lots of trouble getting my 500kHz antenna to match tonight, so late getting on to WSPR tonight. To my surprise (as the antenna current was lower as a result of the rain I think) I got a new report from France - F6CNI in JN19qb which is 418kms away.

Back home - on 500kHz tonight

Just been to Paris, by Eurostar, for our elder grandson's 2nd birthday. At home, the 500kHz antenna is being battered by the very stormy weather at the moment, but I hope to be on the band again tonight ..... if the antenna and roof are still there at teatime.

8 Nov 2009

Voice powered transatlantic 20m test

AA1TJ's historic attempt to span the Atlantic with just a "voice powered" TX (powered only with DC generated by rectifying audio from a LS into which he was shouting) started at 1500 UTC on Tuesday Nov 10th. Power out was about 15mW QRP from the coast of Maine, USA. They had a 2el vertical antenna aimed at Europe and a good clear sea path, but unfortunately the test was unsuccessful, although they did make contact (not voice powered though) with Europe on 160m QRP. For a report see http://www.QRPme.com .

Norway gets some new bands

Stations in Norway now have new, quite large, allocations at 500kHz, 5MHz and 70MHz as well as certain other changes. If you can read Norwegian, see http://www.lovdata.no/ltavd1/filer/sf-20091105-1340.html ).

SM6BHZ hears me on 500kHz WSPR

SM6BHZ heard me at last on 500kHz WSPR at 0556z this morning, so my best DX has now gone up to 951kms with the tiny station. He reported my WSPR signal at -26dB S/N. The distance beats my previous record on the band by almost 100kms. Gus, thank you so much for country number 6 on the band and Joe K1JT for designing the software to make this possible.

7 Nov 2009

Climate change - Copenhagen

A binding agreement in Copenhagen next month seems to be slipping away because no-one wants to make firm commitments on the reduction of harmful greenhouse gas emissions. Personally, I think it would be a tragedy if our leaders came away with just a "wishy washy" set of political statements and nothing concrete. See http://news.bbc.co.uk/1/hi/sci/tech/8345343.stm . For the sake of our children and grandchildren we need ACTION from our statesmen, not words.

500kHz improvements - summarised

The spiral top-hat on the 500kHz antenna.

Since first putting a signal out on 500kHz a few months ago, I believe the ERP has increased by about 18dB. These steps were:
  • Initial PA 500-700mW (0dB reference)
  • PA output increased to 5W (+10dB)
  • Additional grounds added (+2dB)
  • Antenna spiral top hat added (+6dB)
No further changes are planned as I am close to fulfilling my original objectives of seeing how effective a small and simple QRP 500kHz station could be. The two remaining goals are to get reports from Germany and Sweden.

After that, it will be farewell to 500kHz and welcome to the next challenge!

6 Nov 2009

ERP increased on 500kHz (6dB up)

Today I modified my 500kHz antenna introducing a spiral inductance/ top capacity hat consisting of around around 8 "spiralling in" turns in the space occupied by the original 28MHz halo. Seeing my initial reports from M0BMU I am some 5-6dB stronger than I was before, I guess because more of the antenna current is in the 6m long vertical section.

Three new 500kHz reports overnight: F4DTL, PA0AM and G4CAO. The improved antenna efficiency is definitely helping. Also my strongest report yet from GM4SLV.

5 Nov 2009

Top Band WSPR

This evening I moved from 500kHz to 160m to see if I could improve my WSPR DX on topband. At first try, GM4SLV heard me up in the Shetlands. As for 500kHz, my ERP will be considerably lower as I am only using a short 5m long vertical tuned with a ferrite rod ATU. See John's screenshot, that also shows some digital QRM on the same frequency. At 2116z John was copying me on 160m when I was running just 100mW from the TX.

3 Nov 2009

24 stations hearing me on 500kHz

This evening I received a WSPR spot report from F4EMV who is 433kms to the south of me. Yesterday I had one from F0DVZ. This brings the number of different stations reporting my signals on 500kHz to 24 (22 on the WSPR database and 2 others).

Planned 500kHz antenna changes

Before the end of the weekend I intend,weather permitting, to make changes to my small 500kHz antenna. These changes will be:
  1. The 28MHz halo and 6m long feeder will be replaced by a spiral top capacity hat and a slightly longer vertical wire. The effect should be to increase the effective height of the antenna a bit.
  2. Move my TV antenna away from the pole carrying the 500kHz wire. At the moment this is on the same pole, so is probably absorbing energy.
Taken together, I expect another 2-3dB improvement in antenna current and ERP. If these improvements work I'll give it an "on-air" test for a week or so. After this, I'm not planning any further 500kHz improvements as I'll have run out of "keep it simple" options.

More voice powered DX in the USA

Mike Rainey AA1TJ has pushed his DX up to 1329kms on 80m using his Code Talker TX (see left) which uses only the energy derived by shouting into a loudspeaker to power the transmitter - no external DC power sources at all. He worked W4OP at 0133z. Just visible is the tin can used to focus the shouts into the LS cone! I am beginning to think Mike will work some serious DXCC countries in the years to come using his "voice powered" TX. Imagine this rig into a beam on 10m when the sunspots are high.

Mike tells me he is having a go at a 20m version now.

1 Nov 2009

Optical DXing - mirages

Andy Young has an excellent page about optical mirages which is worth reading. Land has been seen hundreds of kms over the horizon as a result of this phenomenon. Indeed there is some evidence that the discovery of Greenland may have been as a result of a mirage off the coast of Iceland. I'm not aware of radio amateurs exploiting fleeting mirages for optical frequency laser DXing.

Our grandchildren

We have two lovely grandsons: Lucien who is 2 and Edward who is not yet 1. This is a picture taken last month when they both came to stay for a few days.

New 500kHz ERP calculation

Some weeks ago Jim Moritz M0BMU made an estimate of my 500kHz ERP based on received signal strength levels at his QTH 69kms away. As I've recently increased my ERP, I asked Jim if he would kindly do a recalculation. These are his latest estimates.

Well, repeating the original calculation, taking your "best" signal level as -12dB on a noise level estimated at 3uV/m in 2.5kHz, your received field strength at my QTH is 0.75uV/m. At a distance of 69km, and assuming only "geometric spreading" propagation losses (i.e. an inverse relation between FS and distance), your ERP is

ERP = (Ed)^2 / 49 , with E = 0.75u, d = 69000, ERP = 55uW

Then we have to consider what additional propagation losses exist; originally I suggested 3dB, which would increase the ERP to 110uW. However, looking at G4FGQ's grndwav4 program, and the ground resistivity around this area, the "ground type" in the program might be 6 - 8, making the ground wave propagation losses between 4.2 and 8.5dB.
This would make the ERP between about 140uW and 390uW.

Obviously there is a lot of uncertainty in this kind of estimate - the two main things are the possible variability in noise levels between when I estimated the noise level and now, and the propagation losses. Both these could contribute several dB variation, so the ERP estimate should only be regarded as "order of magnitude" accuracy.

Still, your signal is certainly much stronger now - one of my nearer-term projects is to make some more accurate FS measurements by injecting a calibration WSPR signal into the loop antenna, which should give a more direct and accurate measurement of the signal levels.

Cheers, Jim Moritz
73 de M0BMU

31 Oct 2009

500kHz - two new reports and a new country

M0DUO (104kms away) spotted my 500kHz WSPR beacon late this evening. Then in the middle of the night my first report from The Netherlands from PA3FNY (JO22nc at 330kms). So, 22 different reports in 11 grid squares and 5 countries with best DX remaining 896kms. Not bad for a 6m long antenna and less than 1mW ERP!

AA1TJ's Code Talker TX

Mike Rainey has now added a schematic to his page on the New England Code Talker CW transmitter powered and keyed only by audio derived from his whistling into a loudspeaker. Mike is hoping to span the Atlantic with a similar TX on one of the HF bands in the years to come, knowing that others have "crossed the pond" with powers as low as 1mW or less when conditions were very good.

LC Meter - a nice kit

Some months ago I bought a PIC based LC meter kit from the Cambridge Radio Club (CDARC). This was a club project and the unit allows very accurate measurements. The kit had remained unbuilt until today when I decided to build it. I'm impressed: it went together well and worked first time. The quality of the kit is first class with a custom case, silk screened PCB and good instructions on the club website. This little box will measure from low pF and nH right through to uF and mH. I can see it being used almost daily. I believe CDARC is to make these kits available more widely. Go and buy one for £50.

20th station hears me on 500kHz

Last night M0WKR (IO94 at 237kms) reported my 500kHz WSPR beacon bringing the total number of unique reporters up to twenty.

30 Oct 2009

The 500kHz ATU

This is a close up picture of my 500kHz ATU which consists of a ferrite rod with thin copper wire tapped at various points to which the antenna and TX are connected. The TX connection is about 5t from the ground end. Also in view are the current transformer (the small toroid with 50 turns secondary) and the small meter used to measure the antenna current.

AA1TJ's "Code Talker TX" - all voice powered

Mike Rainey continues his work on purely voice powered transmitters, in which just the energy in his voice is used to power the RF circuits i.e. no batteries or PSUs at all. He's achieved well over 100kms on 80m this way using a form of CW derived by whistling into a loudspeaker to generate the energy needed. Here is an example of his signal received 109kms away. He can clearly be heard "keying" (actually whistling!) the words of "Mary had a little lamb" in CW.

29 Oct 2009

A good evening on 500kHz QRPp

This evening my 500kHz WSPR beacon has been running from 1700-2300z, still with less than 1mW ERP. As the map shows, this is not preventing 8 stations in 4 countries copying me and many at considerable distance. There has been some transatlantic propagation this evening with SM6BHZ and OR7T being copied in Canada already. These are distances I can only dream of with my tiny station!

A 19th reporter on 500kHz

G4EFE managed to hear my WSPR beacon on 500kHz several times last evening (127kms) bringing the total number of unique stations receiving me to 19 now. I still have work to do to get over the 1000kms distance target.

26 Oct 2009

500kHz - an 18th station hearing me

This morning at around 0930z I received a new report for my 500kHz WSPR beacon, this time from G0HNW who is 200kms away. This brings the total number of reporters to 18. 16 were via the WSPR database and a couple of others via the RSGB LF reflector. Clemens DL4RAJ has been looking for my signal for many nights but thinks I need a further 10dB of ERP before I reach central Europe.

25 Oct 2009

CQWW contest summary - 10m was great

With darkness falling now 10m is going quiet after an exciting 2 days. In the end, my 5W SSB and halo antenna worked 35 stations in 20 countries. DX from outside Europe was not workable this time but I was hearing CX, PY, ZS, 6W, etc so conditions were definitely not bad. Although there were a couple of stateside stations worked from Europe, I did not manage to hear them. The slight upturn in sunspot activity came just at the right time.

10m - the return of the good days?

The CQWW SSB contest has livened things up on 10m this weekend, but the sunspots are also showing signs of activity again and the band generally has been in good shape. In the last 24 hours I have heard DX from 4 continents and confidently expect it to open to the USA this afternoon. Good signals from 9J2B0 on CW and ZS9X on SSB today as well as wall-to-wall Europeans from 28.38-28.62MHz at times. Could this be a sign of the good times to come? Let's hope so as 10m is one of the best allocations we have on HF and a great band for QRP DXing when conditions really improve.

24 Oct 2009

500kHz TX schematic (5W)

This is the current schematic of the 500kHz TX down-converter I use for WSPR. It uses an IRF510 FET PA and generates about 5W from the PA stage, although the ERP is only around 1mW from the antenna. I am planning to add the RX converter stages and an RF sensing circuit so I can use other modes in full transceive on 500kHz. The input is my FT817 at 500mW on 28MHz which is mixed down to 500kHz in an SBL1 mixer.

G0NBD and G4FDD log me on 500kHz

My 500kHz WSPR signal has been logged by new reporters G0NBD in IO83 square (261kms) and G4FDD in IO93 square (212kms) tonight.. This now brings the total number of different stations that have heard me to 16. Not bad with <1mW ERP.

23 Oct 2009

10m - CQWW SSB DX Contest

This BIG HF contest runs this weekend and is sure to make the bands sound busy. I shall be having a go with 5W SSB on 10m only and see what happens.

By 1600z Saturday I'd worked 24 stations in 16 European countries with 5W QRP SSB including C4I, P33W, 4L0A, US5D and TM1O. It is nice to hear 28.4-28.55MHz crowded with stations. Funny how "conditions" magically improve when there is a big contest! In the afternoon there was some decent DX about including LU1HF and PW5G but I did not work them.

EPAD FETs and low voltage TX

This application note shows a 32uW oscillator using EPAD FETs that works with 0.5V supply and may be useful for "harvested energy" TX circuits. The ALD110800 FETs used has also been used to power an amplifier with just a 0.2V supply.

500kHz ATU

Spent half the afternoon going around in circles trying to measure the antenna current since I rebuilt my tiny ATU with a few more taps on the ferrite rod. For reasons I don't understand it was all over the place with my multimeter connected by about 50cms of wire. Instead I built the current meter around a toroid and a small 50uA meter mounted in the ATU and can now repeatably measure the antenna current which is 50mA. With a 5m effective height this is still way below 1mW ERP.

AA1TJ's Voice Powered DSB TX (El Silbo)

Mike has done it again - a superb piece of QRP creativity. This is from his email today:
"AA1MY and W1PID met with me on 3686kHz this afternoon. I was operating a new, DSB version of my "El Silbo," voice-powered transmitter. Both Seab and Jim successfully copied my/their calls and signal reports. Jim commented later that I would have been hard pressed to pick a worse day for the attempt. The propagation was producing severe QSB fading and the QRN was all over the place (peaking at S-7 to S-9 at times). I came away nearly dumbfounded that these two operators could pull enough of my 5mW DSB signal out of the mess, at distances of 100 and 67miles, to complete the QSOs."

22 Oct 2009

Antenna measurements at 500kHz

Matching my antenna at 500kHz has been a bit hit and miss: my technique, if you can call it that, has been to match the antenna "by ear" on RX, adjusting taps on the ferrite rod ATU inductor, to give me the best S-meter reading on the intermod product on 504kHz. Then, with a 3dB pad between the PA and ATU, carefully tweek the tap settings on the ATU for maximum antenna current measured using a toroid current transformer. The 3dB pad is to prevent damage to the PA during the adjustment process. Up to now this has been OK, but I could really do with a better way of measuring the antenna parameters. I'd really like to get an antenna analyser, but cannot justify the expense. I need to check out some other simple, low cost, techniques.

14 stations hearing me on 500kHz WSPR

With a report overnight from G4KPX, I've now been logged by a total of 14 different stations on 500kHz WSPR. 13 are listed here plus G3YMC's report via the LF reflector. There is still room for further, not complex, ERP improvements which should help a few more people detect my very QRP signal. At the moment I have no plans to change my small antenna, just the grounding and ATU.

21 Oct 2009

Another new reporter on 500kHz

Eddie, G3ZJO, has managed to copy my 500kHz WSPR beacon tonight. He is now the 13th station to hear me on the band. No great DX at 79kms, but pleased to be heard by someone else.

6m WSPRing and aeroplanes

Just been active on 6m WSPR this morning running 5W to the vertical colinear. The only person to report me, several times, so far has been G3ZJO who is 79kms to the west of me. What is most interesting are the number of multipath 6m signals seen on the WSPR waterfall with large amounts of Doppler shifts. G3ZJO has been analysing these are has made predictions about the aeroplane flight paths which would result in such traces. Here is the WSPR screen when receiving G3ZJO through an number of such multipath and Doppler shifted traces.

20 Oct 2009

Simple beacon keyer IC: the K-ID2

Looking around for a simple beacon keyer to use with a QRSS beacon, I discovered the ICs sold for $6 (available via Paypal) from K1EL. This 8 pin IC looks ideal as it allows a variety of pre-programmed messages to be selected and sent at predetermined keying speeds.

See http://k1el.tripod.com/KID.html . At $6 each you can hardly go wrong with this. I shall be ordering a few shortly.

Another new country on 500kHz WSPR

My 500kHz WSPR beacon has now been heard in a fourth country: a -26dB S/N report from F5WK who is in the Paris area, a distance of 436kms away to the south. The beacon has now been reported by 11 different stations in four countries so far.

19 Oct 2009

Lambda diode circuits

Mike Rainey AA1TJ has some good tunnel diode ideas on his pages but these devices are hard to find these days. Instead one can create a negative resistance device called a Lambda diode with a couple of FETs or an FET and a transistor. See for example the pages of Ramon Vargas Patron at http://www.zen22142.zen.co.uk/Theory/neg_resistance/negres.htm where he has examples of oscillators and regenerative receivers using Lambda diodes.

18 Oct 2009

500kHz WSPR - a summary so far

So far, spots have now been received from 10 unique reporters (9 via the WSPR database + G3YMC's report using WSJT7 not shown here) in 3 countries and 7 grid squares.

If I could summarise what this tells me it is:

(a) WSPR works very well at 500kHz allowing weak QRPp signals to be detected.
(b) Very low power (ERP <0.3mW) and electrically tiny antennas do work on 500kHz if weak signal modes are used.
(c) 136kHz is worth a go next, even with the poor antenna and very low ERP.

17 Oct 2009

A map to end a fantastic day on 500kHz QRPp

This is the map that says it all: DX that even yesterday I would not have believed possible with a true QRPp microstation on 500kHz WSPR. I go to bed very happy, leaving the beacon running overnight in case any others manage to detect my signals.

K1JT, Joe Taylor, thank you for bringing us this wonderful software package.

What next - 136kHz WSPR?

Having now almost achieved more than I could ever have expected on 500kHz WSPR with uWs ERP, I'm wondering if I should give 136kHz a try with the same antenna and transverter. If I could maintain the same antenna current (20mA measured) my ERP would be around 3-5uW on 136kHz. I'm wondering how far that might get. Almost certainly not too far, but probably enough to be detected by some of the nearer stations

Even greater DX on 500kHz QRPp WSPR - 896kms!

This is getting unbelievable now with such low power and a simple antenna: having just got a report from OR7T I've just now got one at -26dB S/N from GM4SLV in the Shetland Is all of 896kms away! This has been one of the best days ever in my ham radio life.

International DX on 500kHz WSPR

Just received my first 500kHz report from outside England at -26dB S/N from OR7T in JO20ix which is 337kms away.

Using the formula in the RSGB LF Handbook I just calculated my ERP on 500kHz assuming an effective antenna height of 6m (probably less than this in reality) and a measured antenna current of just 20mA. It works out at 315uW ERP. Based on earlier measurements by M0BMU it should now be around 60uW. I suspect he is nearer than the theory suggests. Anyway, still a long way below 1mW ERP even but getting great results with WSPR.

One Laptop Per Child (OLPC)

Good to see that Uruguay has become the first country to provide a laptop for every child attending state primary school according to a report on the BBC News website today as part of the OLPC Initiative.  Over the last 2 years 362,000 pupils and 18,000 teachers have been involved in the scheme, which aims to provide low cost, but high specification, laptops to school children across the world.

500kHz paths

The map here shows the distances spanned on 500kHz WSPR with my QRPp station. I'm now beginning to believe that further will be possible, especially with some skywave propagation. 210kms DX already means I've a chance of being heard in GW, ON, and PA if stations are listening in these countries and uploading spots to the WSPR database.