Tuesday 27 February 2018

A positive day!

Too much grumbling recently!

Today has been a snowy old day, but quite sunny this afternoon.  So I took the opportunity to complete my small solar PV system in the new marsh-located shack, which was much warmer in a sheltered spot from the bitterly-cold, easterly winds than at my home QTH.

I had bought a 100W panel, and this will be fine when I am actually operating and want a top-up to the battery life as I transmit, or a fairly quick charge after some longer periods of transmitting.

But for keeping the battery in a good state of health when I am away for some days, I decided a 10W unit would be much preferable, not least because it is less visually intrusive, and less likely to be damaged by the odd straying sheep or cattle!  This small, fully weatherproof panel was only £17, making it cheaper than most (non-weatherproof) 'battery conditioners' with only 2.5W peak output.

So the 100W panel will simply be deployed as and when I need it, propped up against a post and frame I have installed to keep it steady and aimed to the south.  For now, I have kept costs to a minimum, and used an existing, new 70Ah flooded battery to get going at the shack.  I replaced that, for my home solar PV DC system, with two 15Ah scooter batteries in parallel - costing just £35.  Eventually, I will buy a couple of good quality deep cycle 110Ah batteries.

By 2pm, the battery was connected up, and charge was flowing nicely into it.

All I need now is a new, cheap laptop and soundcard interface for some digital work.  Until then, it will be a bit of SSB, for a change...

Monday 26 February 2018

FT-Hate

This morning, something has changed on 20m, and it's not a good change.

FT8 is a mode that has attracted instant and widespread appeal, providing a quick way to fill the logbook.

Filling the logbook, it seems, is what most people want to do in radio.

What they are also doing is turning what have been relatively disciplined band plans into a 'wild west', 'transmit from the hip' type of radio. 

The change that I saw this morning was the appearance of FT8 up to 3kHz above the nominal QRG for that mode of 14.074MHz.  This takes it not only across the traditional JT65A portion of the band, but also the JT9 section.  Those modes suffer badly in the face of QRM from FT8.

FT8 is without doubt a very useful mode.  But it is rapidly killing the attraction of radio for me.  At this rate, it won't be long before vast swathes of the bands are taken up solely with FT8. 

Control of the bands needs to be reviewed in the light of these fast changes in digital modes.  But national societies are notoriously slow to realise there is something that needs addressing, let alone actually getting around to doing it.

Personally, I think new modes that clearly have the potential to be very widely adopted should go through some official process that identifies where problems may arise, and deal with them before the mode and associated software package is put on general release.  The disruptive ability of these modes is simply too great to be left to the developer or associated groups to dictate terms.




DP0GVN: Propagation as expected

It's been quite interesting to see how propagation to DP0GVN changes with the time of day lately.

The peak signal is quite brief, and occurs at much the same time every day, currently at about 19:25UT from north Wales.

Looking at DX Atlas, which is set to show the terminator and grey line to the end of Astronomical Twilight, it's very clear that the peak signal from Wales to DP0GVN happens when the path is almost entirely along the grey line sector.  By the time DP0GVN is in its own greyline, Wales has gone into darkness, and propagation is much weaker, by roughly 10-15dB, and fails entirely by 20:30-21:00UT.

Over the next month, the path will become increasingly aligned along the evening greyline, as we pass into the Equinox.  It will be interesting to see the expected lengthening of duration of peak signal. 

In the morning, despite a better alignment of the greyline between stations, the strength of ionisation is not sufficient to sustain propagation before or around sunrise.

Path from Wales to DP0GVN at typical peak signal reception time (19:25UT here)


Saturday 24 February 2018

WSPR reception at 132km

G0LUJ has excellent low noise levels, and very sensitive receiving capabilities.

Last night, a moderate geomagnetic disturbance took place for a while.  I wondered again whether this would show up in what I used to think was exclusively ground wave propagation.  But this latest plot shows this not to be the case, as the reception ceases as the evening progresses.

Here is the plot of reception at G0LUJ of my daughter's 200mW into a 1/4 wave elevated vertical in an open field, marshy location.

See the blip?
The reception reports at G0LUJ do not vary very much at all over the day under normal conditions.  But there is a clear outlier at around 01:40UT (24/02/2018), where my daughter's signal suddenly appears from nowhere at a strong -17dB S/N.  It then drops back to near-daytime conditions in the mid to lower -20s dB.

The sharp appearance from the noise is correlated, as seems to be most usually the case, with the recovery phase of the geomagnetic field from a disturbance.  I assume it is a result of reconnection of field lines (which is why the magnetogram below shows a field disturbance at an earlier time, but the enhanced propagation and aurora do not occur until a bit later).

Here's the statistical aurora at 23:40UT, just after the activity had picked up:

NOAA/SWPC

By 01:40UT, things were looking decidedly more lively:

NOAA/SWPC
And the Kiruna magnetogram shows the high-resolution detail:

IRF/Kiruna.


Wednesday 21 February 2018

NDB Listening Challenge

I thought this blogpost by VE7SL the most interesting I've read in a long time.  So interesting, in fact, that I will have a go!

By original uploader (and claimed/alleged photographer) Mintaka10. - Own work, CC BY-SA 3.0.


The sad state of 14MHz

The solar conditions have pretty much reached the lowest they can go - and 14MHz is showing this quite nicely.

The plot shows reception at K9AN of my 200mW WSPR from a quarter wave vertical in an open marshy field environment.  Geomagnetic conditions were quiet throughout.  14MHz supports propagation only from midday until mid-to -late evening, and doesn't recover again until the following noon.

Of course, none of this means you should give up.  There is ample opportunity to make good DX contacts, especially if you can time your activity well.  After all, at only 200mW, this is a pretty critical test of conditions!



IRF, Kiruna.

Friday 16 February 2018

Geomagnetically-enhanced 30m propagation

A moderate increase to Kp=4 last evening (15-16/02/2018) brought the expected enhancement to 30m propagation, relative to the preceding evening:


Magnetogram trace and Kp index for the evening.  Image: IRF/Kiruna.

Thursday 15 February 2018

OX3HI Hearing MW1CFN - 10MHz

Data from 2018 February 10 (quiet geomagnetic conditions):

TX: MW1CFN, 1/4 wave elevated vertical, two elevated radials, 200mW (WSPRlite) running 24 hours/day.  IO73th.

RX: OX3HI.  Receive antenna/receiver not published.


Wednesday 14 February 2018

30m to the Canaries.

EA8BFK has great reception abilities on WSPR.  At the moment, that station also happens to be pretty much on the same terminator line as I am in Wales.

So I thought it interesting to plot the spot strengths over the day, as my 200mW varied at EA8.  The peak, followed by a cliff edge after sunset, is quite remarkable, as is the cliff edge as dawn progresses:




Tuesday 13 February 2018

Snow and SWR

This morning, something very rare indeed happened on Anglesey, although it is hardly unusual in many other places.

The situation is best summarised by a temperature (blue) plot from the nearby, RAF Valley airbase:

In just 50 minutes, the temperature dropped from an already falling 6 degrees Celsius to just under 2 degrees Celsius.  All this in a strong, Beaufort Force 10 wind (which can occur several days a week during winter here in NW Wales).

It also happened to be snowing again - something that only really happens during solar minimum in this coastal location.

When I switched on at 14MHz for some breakfast operating, I found my delta loop was reporting a 1.5:1 SWR.  Normally, it never climbs above about 1.2:1 at my preferred, digital frequencies, and only then during or immediately after extremely heavy rain.

I hoped it wasn't wind damage that would mean time spent in very unpleasant conditions outdoors, conducting repairs.  When I looked at the antenna, the rare combination of weather conditions had led to snow accumulating on the antenna wires, despite the wind, which had then started to melt during the warmer temperatures, only to freeze quickly as the temperature plummeted within just a few minutes.  The antenna was therefore covered in small drop-like icicles, something akin to those American ice storms we often see in the ham press.  The ground was also saturated with melting snow water. The antenna therefore experienced itself as being somewhat electrically longer than expected.

As the morning warmed up, the delta loop match returned to 1.2:1, still higher than normal due to the ground remaining saturated.

I've often heard many people say that their radio reception is 'quieter' during snowfall.  Perhaps the reason for that is that their antenna has become detuned by water in various phases to the point where it is no longer doing what it should be doing at that frequency.  It may also 'detune' those AC and other non-antenna wires that emit the noise, so that it occurs slightly further down the bands.



Monday 12 February 2018

Five days of 30m WSPR

It's been a harsh few days on Anglesey.  Bitterly cold, gale-force winds, snow, heavy rain and even some warm sunshine have variously affected us.

My 30m vertical has flown through it all, as has the superb WSPRlite unit, albeit with the latter wrapped-up in some insulating terylene wool and wooden box!

Here are the range results, set against the best comparison signal I could find.  The dip for a few minutes near 1pm, 11/02/18 was due to a battery changeover:

Across all spot distances, my vertical came in at just over 2dB stronger than the comparison station:
Both stations enjoyed the odd long-haul DX beyond 7000km.  At this range, my signal was a slightly improved, 2.5dB stronger, although I did manage spots from two VK stations, which the comparison station did not:

And finally, the map of all spots for both stations:


Friday 9 February 2018

30m Propagation during geomagnetic disturbance

I've been running WSPR at 200mW with my 30m 1/4 wave vertical from the marsh site for the past couple of days.  It's been very cold and a bit windy, which makes life tough.

Even so, I was lucky to catch a minor geomagnetic disturbance last evening, which started around 19:30UT, and returned to quieter conditions by just after 00UT.  This is the Kiruna plot:

Image: IRF/Kiruna.

The Z component pulses are also interesting in this run.  The other components showed no pulsations.

Z component magnetic pulsations.  Image: IRF/Kiruna.


EA8BFK is a very good receiver, and happens to lie on the exact-same terminator line as my location at this time of year.  This is how he heard my 200mW.  Time along the top, SNR up the side:

It's very interesting to note that my signal was quite weak, but then showed a two-peak phase starting around 21:35UT, when the field was approaching peak southerly deviation.  There is a quieter trough around 22:30UT, just after peak field deviation.  Then, as the field restores to normal, a sharp strengthening of my signal for a few minutes, peaking just after 23:00UT.  That brief signal strength level was not seen again until the advance of dawn-time propagation.

So it seems that 30m, like 20m, provides enhanced propagation during geomagnetic events.

UPDATE.

I've also plotted DP0GVN hearing my 200mW at 10MHz on 08-09 February 2018, the same period as above.


The spots vanish in the approximate period 21:20 - 23:50UT, with a brief 'reconnection' at quite strong levels, but only for a couple of minutes, around 00:00UT.  This superficially coincides with the field recovering to its quiet conditions at that time.  So it looks like the geomagnetic disturbance caused a decrease in propagation in this north-south case.

Thursday 8 February 2018

Oh what a picture! What a photograph!

I remember, many years ago, having a school lesson about family relations.  We looked at a book that had, at its cover, a great image of a wedding, with one family in bursts of smiles, and the other looking dissaprovingly across the newly-married couple at them.

It came to mind when I saw this image:

Smile!  I said SMILE!   Image: (C) EURAO.
Some interesting body language, there!  The two from IARU Region 1 are in the middle, flanked by EURAO chiefs. Interesting also the big step in age profile between the two organisations.  I always have more faith in those who are of working age and have to suffer life's daily troubles, rather than those who spend most of their time in the doctor's surgery, with a bit of committee-sitting in between.

There has been some well-documented and quite energetic antagonism between these two groups in the past couple of years.  Whilst they seem to have partly overcome this, there does rather seem to be a long way to go to achieve family unity, yet!  The only words they could come out with at the end of their December 2017 meeting were these.  They are, pretty much, the kind of empty, unproductive words I hope EURAO can transcend.

In the meantime, whilst everyone learns to get on, do enjoy Tommy Steele in 'Crash, Bang, Wallop'

The Canaries sing!

Good WSPR receive coverage at the Canary Islands this morning on 30m.


But not all Canaries are the same!  EA8BFK was hearing my vertical at 200mW at a SNR of -6dB early morning.  EA8BVP, with an open aspect to the UK, was down at around -17dB.  EA8DBU, with steep, high volcanic ground to his immediate north, was at -12dB.


Tuesday 6 February 2018

Spots, Sunspots and SNOW!

The coming days are due to be pretty quiet, weather wise, although some very rare snowfall has been taking place over night.

A rare sight on Anglesey.
Even rarer than snow these days is a decent sunspot.  A group of spots has just come into view!



Over the weekend, I set up a full-sized 30m vertical I used for Marconi Day WSPR beaconing from Cefn Du, near Caernarfon last year, and which has languished in a plastic bag ever since! 

The site is my 'bolthole' at a local marsh, which proved to be exceptionally good for 40m WSPR.


This is how the past 24 hours have gone in terms of range, and in comparison with a G7 station, who runs a very effective inverted-L, and one of the best on many bands using WSPR:


Clearly, the vertical is doing very well indeed, more especially during the depths of night.

Across all distances, my vertical is just over 4.5dB stronger than the inverted-L.  For brevity, I haven't included the comparison only at DX distances.  But the summary is 6.75dB stronger for distances above 4400km, and 10.5dB stronger at the extreme DX distances. 

Of course, the comparison graph is not the be-all-and-end-all of the story.  That graph only includes stations reporting both transmitter stations.  It doesn't include those spots where only one transmitter was heard.  That information is more important, because being heard is much better than not being heard!


As you can see, there is a large number of DX that did not hear the inverted-L at all.  DP0GVN was hearing me at a robust peak S/N of -14dB, whilst VK5MR and VU3KAZ both heard me at a much more marginal -26dB.  

Again, the marsh site is proving to be an exceptionally good location from which to operate.  

Of course, I have to always sound a cautionary note about too many WSPRlite transmitters and too few receivers being a bad thing.  But, equally, I also have to underline just how important WSPR is as an objective, bias-free means of assessing and comparing antenna performance.  It's a pity that the so-called representative bodies for amateur radio do not see the obvious merit in giving WSPR transmissions the kind of band allocation and protection that beacons enjoy.  Instead, we regularly have to put up with licence-breaching infringements of our existing transmissions from, mainly, RTTY and PACTOR. 

Yet again, the retired middle class, white men sitting on committees are failing to keep up with the times, and their legitimacy must be called into question.





Monday 5 February 2018

Mind your sine wave!

As attetion continues to turn here onto off-grid powering of the station, I've been looking at the small collection of AC inverters I have around the house.

First up was a small, cheap-and-Chinese inverter of about 80W maximum load given to me by my RV-fanatic neighbour, who has always helped, rather than stand in my way as an amateur radio operator.

This wasn't a pretty sight:


 
Alarmingly, I have previously run my LED TV on that inverter.  That will stop, straight away!

Next, a 30-year old low wattage (ca. 12W max) inverter that a university electronics technician gave me an equally long time ago.

Again, this wasn't good:

I think both inverters have the recycling centre as their immediate destiny!