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...
Tuesday, 27 February 2018
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.
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.
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.
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| 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.
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:
By 01:40UT, things were looking decidedly more lively:
And the Kiruna magnetogram shows the high-resolution detail:
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 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:
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| NOAA/SWPC |
By 01:40UT, things were looking decidedly more lively:
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| NOAA/SWPC |
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| 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!
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| 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!
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!
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| IRF, Kiruna. |
Sunday, 18 February 2018
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