5 Dec 2023

10m QRP WSPR (Tuesday)

My 10m WSPR TX beacon is back on at 500mW.  500mW seems like QRO compared with 500uW!!  At 1045z, no spots.

UPDATE 1132z:  12 spots of my 500mW. Reports suggest 500uW would not be copied. 50mW would have got some spots, even 5mW.


UPDATE  1738z:  34 spots of me.

UPDATE  1915z:
Quite a few stations might have copied me at 500uW (see table).

Earth-electrode "antenna" in the ground

Let me say from the outset that I have no firm conclusions on how this works, but work it definitely does.

My theory is that it forms a loop in the ground, so the effective loop area increases as the frequency is lowered. If the spacing between the electrodes is increased the effective loop increases in diameter. This structure has been used (by others) for amateur radiated tests at extremely low frequencies. In my case it has proved effective with QRP up to 60m. On 630m WSPR it has proved very effective with reports from Finland with low mW ERP. It is almost invisible, with the XYL and neighbours not even aware it is there! 

If the loop theory is correct a low impedance is needed as the electrodes enter the ground, but a high impedance between the electrodes so the effective loop diameter is large.

At present, I am using a mains earth (please check your mains earth is suitable) at one end, but tests at the old QTH showed that using 2 electrodes in the ground worked just as effectively.

Before anyone says that it is the wire back from the far electrode that is doing all the radiating, I tried putting the return wire on the ground with very little difference in performance.

See https://sites.google.com/view/g3xbm4/home/antennas/earth-electrode-antennas .

630m QRP WSPR overnight

 


In all, 9 stations spotted my 10mW ERP from the earth-electrode "antenna" in the ground (see table).

Infected blood - NOT amateur radio

At the height of the AIDS epidemic, the UK government effectively gave infected blood to people suffering from hemophilia and other conditions.  Many caught AIDS. Many died.

Years later those affected are still awaiting full compensation. Last night the government suffered a defeat in Parliament as many MPs sided with the opposition parties on this scandal, demanding that compensation be paid within 3 months of the bill passing.

See https://www.bbc.co.uk/news/uk-politics-67615379 .

Unexploded bomb - NOT amateur radio

On the news was a piece about a couple that had an unexploded bomb in their flowerbed. It had been there for many decades and they always assumed it was safe. It was found to be live after all! The wife frequently used it to bang her trowel on!

Oscar 100 narrowband activity


Every few weeks I take a look at activity levels on Oscar 100, which is a geosynchronous amateur satellite. 

Personally, I was expecting activity to be far higher. Indeed, it has encouraged some to experiment with microwaves, but it has not really caught on with DXers. There are many advantages: DX without QSB at any time within the footprint of the satellite, no need for linears, neighbour friendly fixed antennas that could be at ground level, etc..

There are no rigs from Japan probably as the satellite does not cover the USA and Japan. I suspect this is one reason why they have not bothered.

See  https://eshail.batc.org.uk/nb/ .

LoRa

LoRa modules are available from Amazon and I expect quite a few other sources. To my knowledge, two people locally have experimented with 868 MHz LoRa modules. I am not sure if this was for commercial reasons or just for fun. 

As far as I know, anyone  may use the licence free ISM bands (certainly in the UK) as long as the interface conditions are met. This often means low power and the acceptance of interference. At 868 MHz there are some odd duty cycle limits I think.

If you do not have an amateur radio licence, this may be a route to experiment.

Sunspots- Tuesday December 5th 2023

 Solar flux is 138 and the SSN 113. A=9 and K=3.

4 Dec 2023

Packhorse bridge - NOT amateur radio

This bridge was once on the main route from Cambridge to Bury-St-Edmunds. It is in a village called Moulton, near Newmarket. Right next to it is a ford.

630m QRP WSPR (Monday)

My 10mW ERP 630m WSPR from the earth-electrode "antenna" in the ground was turned on at about 1750z. 

UPDATE 2130z:  Spotted by 6 stations. Spots by Dave G4FEV (57km) make a change from 70cm SSB!! I am wondering if there are fewer WSPR 630m users as more people are using some of the newer modes in WSJT-X?

SAQ , Sweden

SAQ is a 17.2 kHz CW alternator TX at Grimeton in Sweden. It is the oldest alternator TX in the world at about 100 years old. They have test transmissions with the next one scheduled for Christmas Eve. It is a good test of VLF receive setups. It is usually widely heard in Europe, and sometimes further.

See https://alexander.n.se/en/the-radio-station-saq-grimeton/saq-transmissions/ .

University of the Third Age - NOT amateur radio

The U3A is an organisation to allow older people to enjoy learning just for fun. Unlike years ago, there are no exams and no swatting. Learning is purely for fun. I often choose things that I know little about. It makes so much difference just learning for fun.

Every Thursday, I attend a talk about the Low Countries. Last week it was about Bruges.  The speaker is excellent. We are lucky in Cambridge to have a very wide choice. Often the lectures are by ex University of Cambridge lecturers!

Walk - NOT amateur radio

 These ducks were on the river when we went for a walk last week.

Minced pies - NOT amateur radio

In the run-up to Christmas nothing beats minced pies and a piece of cheese. My wife makes her own and these are so much better than shop ones, with thinner pastry. I roll out the pastry.

8m QRP FT8 (Monday)

At 1110z I QSYed to 8m FT8 with my 2.5W and dipole.

UPDATE 1450z:   No spots on TX. Just ZF1DM (7752km) on RX.

Me in the shack

 


This must have been a few years ago after a tidy-up. At the moment it is badly in need of a clean!!

630m FT8 overnight

Overnight (last 12 hours) my 10mW ERP 630m WSPR was spotted by 8 stations (see table). I think there was another station spotting me earlier. 

At the moment, I am still on 630m WSPR.

10m WSPR 500uW TX test - last day

Although I shall run my beacon at 500uW for another day, I shall probably go back to full power (500mW!!) tomorrow. Even with 500uW (0.5mW), it is enough to get some spots if conditions are good, even with my low antenna.

UPDATE 1242z:  No spots of me at 500uW (0.5mW).

Sunspots - Monday December 4th 2023

 Solar flux is 139 and the SSN 107.  A=11 and K=2.

3 Dec 2023

Why? - NOT amateur radio

As much as I think the massacre in Israel on October 7th was totally wrong, I cannot see long-term good coming out of the response. All that is achieved in the end is yet more hatred.

Although unsure of the answer, it surely has to be based on mutual respect and talking, not bombs. Many of my best friends are Jewish and I am sure they hate the present situation as much as I do.

See https://www.bbc.co.uk/news/live/world-middle-east-67605703 .