Simple 80m rig (not tested on-air yet)

This is the schematic of a little experimental 80m CW transceiver. It puts out about 60mW and is only moderately sensitive, although I have not managed to accurately measure it yet. Offset between RX and TX is about 400Hz but more can be obtained by closing S1. It should be used with a low pass filter really.

Some QRP operating

This is a picture of me in my shack. I had just completed some homebrewing and was having an SSB QSO. See next post for details of the homebrew experimental transceiver I had been working on.

Dutch online SDR now has 500kHz

The Twente University online SDR in The Netherlands has now got a 500kHz receiver. It works well and SM6BHZ's SSB beacon was coming through very well a few moments ago.

Want to launch your own satellite? You can!

Interorbital Systems of California have introduced a kit to allow you to build your own satellite! The price of the Tubesat kit ($8000) includes the cost of a launch into space as well.

More overnight 500kHz WSPR TXing tonight

Tonight I shall have another go at breaking the 1000kms barrier on 500kHz WSPR. If you decode me, be sure to upload your report to the WSPR online database please.

10m WSPR

This morning I've been WSPRing on 10m again. G4IKZ 18kms away is a good signal and he has been heard in Italy. G4IKZ is copying me, but no DX reports yet. There is a great deal of aircraft Doppler on local signals. We have the Mildenhall and Lakenheath airbases some 20-30kms away, so I expect it is because of aircraft taking off, circling and landing.

Transatlantic reception on 500kHz

This evening, early, the transatlantic WSPR stations are coming through well into Europe. So far I've only seen WE2XGR/6, running 100W, appear on the screen on 511.5kHz, which is above the UK allocation. This is a new transatlantic station for me. The signal is varying in QSB with around 8 minutes between peaks of signal.

UPDATE: I eventually moved off 511.5kHz at 8am this morning and WE2XGR/6 had been coming in all night until then. At best it reached -14dB S/N with me on one occasion but usually it was around -20 to -25dB S/N level. Also copied was WE2XGR/2 who was running 50W. He was audible until 0638am

10m WSPR

This afternoon, for a change, I loaded up my 5m vertical on 10m and have started to WSPR at 5W level. So far, only one report received from G4IKZ just 18kms away at -13 to -15dB S/N. He is running 10W and is about -4dB S/N with me.

So near but so far on 500kHz

Last night again produced some decent DX reports with the 1mW ERP 500kHz station, but still I'm 10kms short of the magic 1000kms target. Best was DL4RAJ at 990kms who spotted be many times during the night. A new reporter this morning was M0GNM in IO91 - thanks for the report.

Haiti appeal - our help is needed

It was good to hear that the GQRP club made a donation to the aid appeal for the survivors of the terrible earthquake in Haiti. The sheer scale of this is terrifying but, if we can afford to do so, we ALL need to give something to help these poor people. In the UK donations may be made on-line via the Disasters Emergency Committee website.

K4TWJ (the "One Transistor Marvel" man)

Yesterday I heard that Dave K4TWJ is in hospital having had a massive heart attack on New Year's Eve. His XYL Sandy, WB4OEE, reports that he is improving and getting stronger. Dave writes articles in several US magazines including CQ and his design for a very simple one transistor transceiver appears in the International QRP Collection book available from the RSGB.

Simple LF/MF QRP transmitter

VE7SL has a neat little LF/MF TX circuit on his website which is suitable for QRP 136 or 500kHz operation. Its original application was for 160-190kHz part 15 "lowfer" beacons in the USA. I used the same PA arrangement in my first 500kHz transverter and I can confirm it is very reliable and robust.

Overnight on 500kHz (1mW ERP)

21 unique stations reported hearing me on 500kHz WSPR last night, but still the 1000kms target has not been reached - so close but so elusive. On RX, I was able to copy LA3EQ, PA0A and SM6BHZ as well as the local Gs, but no transatlantics.

Latest sunspot predictions

The recent upsurge in sunspots has been a good sign that we are now strongly on the upward curve of cycle 24 at last: most days there are spots and the solar flux levels are climbing. However, this is in line with NOAA predictions and their latest table of expected sunspot numbers is unchanged, I think, with a peak smoothed sunspot number of 90 expected in  May 2013.

500kHz looking like 30m!

Just look at this WSPR screen from 500kHz at 2330z this evening. There are G, PA, LA and SM signals coming through pretty well. 500kHz is now getting quite busy at night and it's harder to find a clear spot in the 200Hz WSPR sub-band!

Google ads quirk

Since I mentioned the Flea QRP transceiver some of my banner ads have come up advertising Flea spray! As I've mentioned them again I expect they will remain until I use some other key words in my text.

Self assembling solar cells?

Interesting article on the BBC Technology page about a possible technique for "self assembling" solar cells and other electronics products. See http://newsvote.bbc.co.uk/1/hi/sci/tech/8452912.stm

Yet another try at 1000+kms on 500kHz

Overnight tonight (Tuesday/Wednesday) Martin OE5HYM will be listening for my WSPR signals. Martin is 1128kms away in Austria and he has a well-equipped receiving station. So, I am hopeful that breaking the 1000kms barrier is now just a matter of time. With luck, there will be more stations in the 1000-1200kms range staying on overnight too. However the solar conditions appear less favourable for LF propagation tonight.

Another try at the 1000kms target tonight

Again there are a LOT of stations in Europe listening on 500kHz WSPR and I've already had reports tonight from stations 685, 701 and 896kms away from me. The beacon will again be run through the night to see if anyone over 1000kms away manages to decode me. Unfortunately I think the main problem will be there won't be anyone listening in the 1000-1200kms range: TF3HZ is much further away (1836kms) and the station in Poland and one near Stockholm seem to have gone to bed and switched off :-(

Sixbox video added

As promised, I've put a small video about the Sixbox 6m AM transceiver on my YouTube channel. You will recall that the Sixbox was a small 40mW AM transceiver derived from the 2m Fredbox. This version is built "ugly style" in a diecast box and has a tunable receiver covering about 5MHz around 49-54MHz. The Sixbox is described in SPRAT 140 and also in the German magazine QRP-Report. It is also described on my website.

500kHz ATU video

Just put a short video of my tiny ATU for 500kHz onto YouTube.

A good night on 500kHz

Last night I ran the WSPR beacon again overnight hoping to beat my magic 1000kms barrier using the 1mW ERP station. Unfortunately there were no reports quite that far (990kms was the best), but it was an excellent night with lots of DX reports. DX is of course relative: G4JNT was copied in Alaska and several stations were heard across the Atlantic. Still for my modest power I was well pleased.

M1KTA's version of the 40m Flea Transceiver

Dom Baines M1KTA has just completed his version of the Flea transceiver for 40m and it looks a very neat job. Dom describes this on his blog and it is well worth a look. He gets 1.3W out from a 2N3866 PA. I look forward to working him very soon.

Gnat-1: 1 transistor transceiver from SPRAT 138

Am I alone in struggling with this design from SPRAT 138?

Today I did a breadboard version for 80m on the bench. On TX I had no problems (as long as I grounded the transistor's emitter directly on TX), but on RX the performance was diabolical and no better than a crystal set with injected carrier. I cannot quite fathom out the function of the transformer T2 or why the key is grounding the secondary of T2. As described in the article I would have thought T2 could be removed and simply key the emitter to ground on TX and decouple a larger (variable) emitter resistor on RX.

Has anyone had success with this design on RX? It may well be me!

500kHz new reporters: DL-SWL and G3JKV

No further DX records broken in the last 24 hours but a couple of new stations reporting me: DL-SWL who is in JO52 some 701kms away and G3JKV who is in IO91. Thank you for your WSPR reports.

Did my 1mW ERP reach Moscow on 500kHz last night??

This evening, Andrey RN3AGC sent me an intriguing screenshot taken from his PC in Moscow 2433kms away from here. It shows a very weak trace on the screen at the frequency which only G3XBM was operating last night. It is just possible this was my 1mW ERP signal. If so, it was too weak for the WSPR software to decode. You have to look very hard to discern the trace.

Hello Roger,

Probably? :)
Yesterday only you on this frequency worked.

73 Andrey

New G3XBM videos on YouTube

Today I've added a couple more videos to my G3XBM YouTube Channel. They are of the Fredbox 2m AM transceiver and of the FETer 80m CW transceiver. The latter uses just 14 parts but works remarkably well. I hope to add more videos about my projects in the next few weeks.

990kms on 500kHz

My 1000kms distance target on 500kHz WSPR has still not been met, but now by just 10kms: last night I was heard quite strongly at -18dB S/N by DL4RAJ 990kms away in JN68kj. The signal report and distance now make me really believe that further really is possible with the 1mW ERP station.

3 new reporters on 500kHz

Last night I left the WSPR beacon running overnight in the hope that I'd break the 1000kms barrier at last. Again, my best report from Germany was 40kms short. However, I did get reports from 3 new stations (DL3NDR, PA0LCE and from SWL Mark in Edinburgh) overnight bringing the total number of unique reports for 500kHz WSPR to 61 plus two reports for CW QSOs. In all then 63 stations have now heard my 1mW ERP signal.

Methane release - higher than expected

From the BBC website:

"Scientists have uncovered what appears to be a further dramatic increase in the leakage of methane gas that is seeping from the Arctic seabed. Methane is about 20 times more potent than CO2 in trapping solar heat. The findings come from measurements of carbon fluxes around the north of Russia, led by Igor Semiletov from the University of Alaska at Fairbanks."

See http://newsvote.bbc.co.uk/1/hi/sci/tech/8437703.stm

G0IMG (Mike) a silent key

Yesterday I heard that G0IMG, Mike Gotch, from Saffron Walden has died. Mike used to be one of my bosses years ago at Philips. Mike became a keen 10m and 6m DXer. About a year ago he had a serious stroke and was left severely paralysed. RIP Mike.

40m WSPR with 100mW

For a change I put my WSPR beacon on 40m this afternoon and set the output power to 100mW. Within minutes there were reports coming in and some are very good. For example, -9dB S/N from a German station suggesting another 20dB attenuation (i.e. 1mW out) and the signal might still be copied. A few minutes later and there was a log from an LA 1500kms away. Incidentally, several CQs on 40m CW with 1W failed to get a response an hour earlier! I'm now trying 100mW on 30m.

500kHz 1mW ERP DX record: 960kms

Last night, a new personal DX record was set on 500kHz WSPR with a report from DG6RCH not far from the Austrian border in S.Germany. He was located in JN68 square and the distance was 960kms. Just 40kms more to beat the 1000kms barrier!

Also last night I heard EI6IZ for the first time.

500kHz good again tonight

Switched on my WSPR station earlier. Already had reports from 9 different stations on the database as far apart as the Shetland Is (GM) to the north (896kms) plus PA and ON to the east (337kms).

Last night I partially decoded WD2XSH/17 (just QTH locator), who I received twice in December. Still hoping that my 1mW ERP signal will break the magic 1000kms barrier (just 49kms more to go). There are LOTS of stations listening on 500kHz WSPR at the moment, so this must be one of my best chances tonight.

The 500kHz antenna was coming down to make way for the 28MHz halo, but I think I'll wait a few more weeks, not least because the roof is frozen and the antenna is covered in snow!

Another new report on 500kHz

Conditions on 500kHz have been good again this evening. F6CNI near Paris was receiving me at an incredible +2 dB S/N on WSPR. I cannot understand how my signals can be this strong so far away! Also tonight, a new reporter, DL2SEA heard me 442kms away in JO30 square. The screenshot shows my signal as he received it.

Web SDR locations

There are now a number of places on the internet where one can find and operate on-line software defined radios (SDRs). For a list of these go to http://www.websdr.org/. One of the best, now streaming 7 different bands, is http://websdr.ewi.utwente.nl:8901/ which is located at Twente in The Netherlands. I have used this one to hear my QRP signals on 40m from the UK. There is a very slight delay but I was able to hear my 400mW signal very well. Another has a recording of the 23cms band during an ARRL EME (moonbounce) contest using a 25m dish: you can tune the band and hear some amazingly strong CW QSOs via the moon.

500kHz transverter video

There is now a short video clip on YouTube describing my 500kHz QRP transverter. Sorry the quality is not brilliant but I had problems holding the camera, pointing the pointer and deciding what to say! Still, it gives you some idea what is inside the box.

See http://www.youtube.com/watch?v=86K19chQ06Q

Another new report on 500kHz - EI6IZ

Thsi evening, conditions on 500kHz are good again with reports from the G, ON, DL and EI. The Irish station was EI6IZ in IO53 square at a distance of 669kms. This brings the total number of stations reporting my 1mW ERP 500kHz WSPR beacon to 56 in 9 countries.

Welcome to 2010

A very happy and peaceful New Year to you and your families. Do you have any New Year resolutions? Mine are:

1. To complete my QRP DSB/CW transceiver for 10m (possibly SSB using a phasing TX)
   
2. To make a DSB version of the Fredbox for 6m or 2m
3. To design and build some more very simple "micro-transceivers" for HF and 6m use
   
4. To do one long walk once a week
   
5. To give up sugar in tea and coffee
   

We'll see how well I succeed this time next year!

2009 countries worked

At the end of the year I've been through the logbook to see how many (few?) countries I worked in the sunspot minimum year with QRP.  Overall I worked 47 countries with 34 worked on 10m and 15 on 6m. This is fewer than previous years as I spent quite a lot of time in the second half of the year on WSPR beaconing, especially on 500kHz. With improving HF conditions I expect to better this total in 2010.

On WSPR, I was very pleased to end the year with 54 unique reports on 500kHz from stations in 9 countries and all with just 1mW ERP to a tiny antenna.