There are clearly those in the radio community - and this includes some societies - who think that a contest gives them the right to operate with only their interests in mind.
This weekend, some CW contest or other is underway. WSPR is once again being completely ignored, with the globally-important beacon mode, which takes up a very narrow spot frequency, being obliterated.
Ham radio's standards are really very poor. I find it difficult to reconcile someone in the US being fined $25,000 for failing to identify, when there are, this weekend, hundreds of stations breaking the terms of their licence by interfering with ongoing transmissions.
I like ham radio, but once again, find myself questioning whether contests have taken over the hobby - and have undermined gentlemanly operating.
Saturday 28 November 2015
Wednesday 25 November 2015
Mode Breakdown
No, not that sort of breakdown. It's a simple chart of which modes I've used since about 2010.
The fraction of PSK31 surprised me, because I've not used it regularly for a couple of years. It reflects a busy period during sunspot maximum, typically on 15 and 10m. JT65A is taking over as the default mode for me, mainly because it offers a way to communicate wihthout shouting down a microphone when others are asleep. It's also useful because you can do other things at the same time. JT9 is also slowly increasing, especially after e-QSL introduced its award for that mode.
It's a shame that ROS and OLIVIA have so few takers. These are really very robust weak signal modes that allow comfortable live typing QSOs, often with very interesting people. RTTY remains an annoying 'last resort' mode for me, although it can also be very useful under marginal conditions. I just wish more RTTY operators would avoid selecting a frequency that interferes with WSPR mode.
Sadly, CW remains a 'to do' mode, having never really made the effort to learn it. The attraction of simple, QRP operating whilst portable might well change that state of affairs soon!
The fraction of PSK31 surprised me, because I've not used it regularly for a couple of years. It reflects a busy period during sunspot maximum, typically on 15 and 10m. JT65A is taking over as the default mode for me, mainly because it offers a way to communicate wihthout shouting down a microphone when others are asleep. It's also useful because you can do other things at the same time. JT9 is also slowly increasing, especially after e-QSL introduced its award for that mode.
Sadly, CW remains a 'to do' mode, having never really made the effort to learn it. The attraction of simple, QRP operating whilst portable might well change that state of affairs soon!
Tuesday 24 November 2015
VK9WA: Now it's Over.
VK9WA, the much-heralded DXpedition to Willis Island, has just come to an end.
The team on Willis were meant to be using - and were apparently sponsored by - the fairly new Crank-IR folded vertical antenna, something that many ops will find useful for portable work.
To be fair, the team put up a pretty good signal, at least as heard with my 3-ele monobander, on 12m. That said, you could clearly detect the advancing day, as their signal went from 51 to, briefly, 59, before plunging after a mere couple of minutes back to 51 or worse.
Inevitably, the team were very busy with people desperate to be the one to be heard on the other side of the world.
I regret to say VK9WA slipped into that pretty bad habit of using increasingly wide sections of an already narrow 12m band. Comments on the 17m cluster reflected this concern. Specifically, on the morning of 23 November, the team were working "5-30 up" - an astonishingly wide range for 12m, and one that, at it's upper limit, would be out of band on the USB mode then in use.
The team on Willis were meant to be using - and were apparently sponsored by - the fairly new Crank-IR folded vertical antenna, something that many ops will find useful for portable work.
To be fair, the team put up a pretty good signal, at least as heard with my 3-ele monobander, on 12m. That said, you could clearly detect the advancing day, as their signal went from 51 to, briefly, 59, before plunging after a mere couple of minutes back to 51 or worse.
Inevitably, the team were very busy with people desperate to be the one to be heard on the other side of the world.
I regret to say VK9WA slipped into that pretty bad habit of using increasingly wide sections of an already narrow 12m band. Comments on the 17m cluster reflected this concern. Specifically, on the morning of 23 November, the team were working "5-30 up" - an astonishingly wide range for 12m, and one that, at it's upper limit, would be out of band on the USB mode then in use.
Tuesday 10 November 2015
Magnetic Loop Matching
Yes folks, it's that time of year when autumn turns to winter, and the jet stream brings day after day of hurricane-force winds to north Wales.
This is the time to fetch the magnetic loops, so that I can keep going on the lower HF bands whilst the winds flatten everything outside.
Whilst magnetic loops are available from a limited number of makers, their price is very high. One of the latest entrants is Inac of Spain, who seem to have a very nice line-up. But at 1000 Euro for the rather small 80m upwards loop of the 3-30MHz version, I'm happy to make my own and simply tune manually.
Last year, I had a nice G3JKF three-loop array to play with. It was successful and very easy to match, but it did take up a lot of room in the kitchen! So, this year, I'm back to a single loop of 1.2m per side, made of wide, 28mm copper tube. Any wider than this, and you start to cry at the hardware shop's checkout!
Wider tube increases efficiency somewhat at the lower bands, but it is not really necessary to use much above 15mm; according to Sutherland, gain calculations for loops are vastly out of kilter with reality (up to 30dB!), owing to questionable use and misinterpretations of the Chu-Wheeler criterion, first published in the late 1940s. Look these up online for further understanding.
Loops can be difficult to tune owing to their very high Q. So, this is how I tame my loop:
(1) Use a 4:1 balun near the feedpoint.
(2) Connect one side of the balun output to the centre of the bottom tube of the loop. Soldering is best.
(3) Connect a longish, stiff wire like hard-drawn copper to the other balun's pole. Run this about 1cm or less from the bottom tube, parallel with it. Run it up maybe 60-70% of one upright side and connect (tap) with a crocodile clip or hose clamp/Jubilee clip.
(4) Adjust the position of the tap such that you get the best matching/lowest SWR.
(5) Turn your capacitor until you hear the loudest signal. This should be close to perfect matching.
(6) If you can't get below 1.5:1 or so, adjust the position of the tap, make sure there are no metal objects around your loop which are detuning it, and adjust the shape/positioning of the gamma match wire. I have previously found, under advice from G3JKF, that running a second wire directly from the gamma match pole of the balun directly to the tap point, in addition to the parallel wire, gives a good, broad matching that makes achieving low SWR much easier. In other words, this looks like a triangular loop, connected at the upper apex to the normal tap point up one side of the loop. It's a kind of parallel gamma match.
(7) To work out what kind of capacitor you need for your particular diameter pipe and loop, use this site, which has proven tobe spot-on in its predictions for me (though I suspect the efficiency output is based on old formulas, and hence underestimates efficiency.) Vacuum capacitors, if you can find (and afford) them, are better than air-spaced ones, but both can be used to good effect.
So there's the theory. Does it actually work?
Well, have a look at this 11/11/15 results on 60m WSPR. I'm one of only four stations being heard by VK7BO from anywhere; the map shows all stations active on the band. And no, this wasn't a 'ten minute' wonder where the spots simply reflect transient conditions - this situation persisted for some time. Not bad for a kitchen-based loop!
Happy building!
This is the time to fetch the magnetic loops, so that I can keep going on the lower HF bands whilst the winds flatten everything outside.
Whilst magnetic loops are available from a limited number of makers, their price is very high. One of the latest entrants is Inac of Spain, who seem to have a very nice line-up. But at 1000 Euro for the rather small 80m upwards loop of the 3-30MHz version, I'm happy to make my own and simply tune manually.
Last year, I had a nice G3JKF three-loop array to play with. It was successful and very easy to match, but it did take up a lot of room in the kitchen! So, this year, I'm back to a single loop of 1.2m per side, made of wide, 28mm copper tube. Any wider than this, and you start to cry at the hardware shop's checkout!
Wider tube increases efficiency somewhat at the lower bands, but it is not really necessary to use much above 15mm; according to Sutherland, gain calculations for loops are vastly out of kilter with reality (up to 30dB!), owing to questionable use and misinterpretations of the Chu-Wheeler criterion, first published in the late 1940s. Look these up online for further understanding.
Loops can be difficult to tune owing to their very high Q. So, this is how I tame my loop:
(1) Use a 4:1 balun near the feedpoint.
(2) Connect one side of the balun output to the centre of the bottom tube of the loop. Soldering is best.
(3) Connect a longish, stiff wire like hard-drawn copper to the other balun's pole. Run this about 1cm or less from the bottom tube, parallel with it. Run it up maybe 60-70% of one upright side and connect (tap) with a crocodile clip or hose clamp/Jubilee clip.
(4) Adjust the position of the tap such that you get the best matching/lowest SWR.
(5) Turn your capacitor until you hear the loudest signal. This should be close to perfect matching.
(6) If you can't get below 1.5:1 or so, adjust the position of the tap, make sure there are no metal objects around your loop which are detuning it, and adjust the shape/positioning of the gamma match wire. I have previously found, under advice from G3JKF, that running a second wire directly from the gamma match pole of the balun directly to the tap point, in addition to the parallel wire, gives a good, broad matching that makes achieving low SWR much easier. In other words, this looks like a triangular loop, connected at the upper apex to the normal tap point up one side of the loop. It's a kind of parallel gamma match.
(7) To work out what kind of capacitor you need for your particular diameter pipe and loop, use this site, which has proven tobe spot-on in its predictions for me (though I suspect the efficiency output is based on old formulas, and hence underestimates efficiency.) Vacuum capacitors, if you can find (and afford) them, are better than air-spaced ones, but both can be used to good effect.
So there's the theory. Does it actually work?
Well, have a look at this 11/11/15 results on 60m WSPR. I'm one of only four stations being heard by VK7BO from anywhere; the map shows all stations active on the band. And no, this wasn't a 'ten minute' wonder where the spots simply reflect transient conditions - this situation persisted for some time. Not bad for a kitchen-based loop!
Happy building!
Monday 9 November 2015
Galvanised Steel Wire
If you hunt for antennas on the likes of that famous internet auction site that must not be named, you will find an awful lot of ready-made units featuring galvanised steel wire these days.
Galvanised wire is very strong, that is for sure. It also conducts your applied current pretty well. Not as well as a pure copper wire, though.
Does this make any difference to the performance of your antenna? Overall, whilst calculations and theory, discussed with some degree of civility here, show that there will be somewhat less gain for an antenna made of steel, the operating experience will typically be that steel performs almost as well as copper.
The exact composition of steel wire, and how it is galvanised or coated dictates how precisely it compares to copper. Some are almost as good as copper, others will have significant gain losses.
The way to approach steel wire is this: why do you want to use it? Copper is the standard, proven material that ought to be used wherever possible. This means that only in violently windy and/or cold situations, or where access to an antenna after initial erection is extremely difficult should you consider using anything other than copper wire.
Keep in mind, too, that galvansed steel wire does corrode. That's because the ends, which are cut at some stage, expose the core to oxygen and moisture. This propagates along the rest of the wire at a modest but surprising rate, where the plastic coating serves only to maintain a moist atmosphere, hastening corrosion.
Stainless wire is also sometimes discussed, but it is also something to avoid in general, even though Optibeam are claimed to use it in their multi-band nested Moxon beam, which is a pretty expensive antenna.
FlexWeave is very strong, but rather heavy for some antenna designs. Kevlar-reinforced wire is also extremely strong in tension, and three times lighter than FlexWeave, but will fail from metal fatigue in bending eventually (about 2- 3 years in frequent winds.)
My advice is to use standard Kevlar-cored wire for all applications, and accept the need to replace it every few years.
Galvanised wire is very strong, that is for sure. It also conducts your applied current pretty well. Not as well as a pure copper wire, though.
 |
| Strong, but not ideal... |
Does this make any difference to the performance of your antenna? Overall, whilst calculations and theory, discussed with some degree of civility here, show that there will be somewhat less gain for an antenna made of steel, the operating experience will typically be that steel performs almost as well as copper.
The exact composition of steel wire, and how it is galvanised or coated dictates how precisely it compares to copper. Some are almost as good as copper, others will have significant gain losses.
The way to approach steel wire is this: why do you want to use it? Copper is the standard, proven material that ought to be used wherever possible. This means that only in violently windy and/or cold situations, or where access to an antenna after initial erection is extremely difficult should you consider using anything other than copper wire.
Keep in mind, too, that galvansed steel wire does corrode. That's because the ends, which are cut at some stage, expose the core to oxygen and moisture. This propagates along the rest of the wire at a modest but surprising rate, where the plastic coating serves only to maintain a moist atmosphere, hastening corrosion.
Stainless wire is also sometimes discussed, but it is also something to avoid in general, even though Optibeam are claimed to use it in their multi-band nested Moxon beam, which is a pretty expensive antenna.
FlexWeave is very strong, but rather heavy for some antenna designs. Kevlar-reinforced wire is also extremely strong in tension, and three times lighter than FlexWeave, but will fail from metal fatigue in bending eventually (about 2- 3 years in frequent winds.)
My advice is to use standard Kevlar-cored wire for all applications, and accept the need to replace it every few years.
Tuesday 3 November 2015
2m Tropo
This autumn has been a very unusual one in Wales, as much of the UK. For one thing, it's been very warm; the first days of November have seen temperatures reach 17 degrees Celsius even here in the north of Wales. Then there's the total absence of wind. A normally severe QTH near the coast has been becalmed for weeks on end, with only a day or two of moderate winds interrupting proceedings.
Last night, idly twiddling about on 2m, I started hearing some Northern Irish stations coming in. Then some of the marginal repeaters were easily accessed. Within a few minutes, I was having easy simplex QSOs with both the south and north of Ireland.
Strangely, one caller from the Isle of Man was pretty weak. He did say something about his antenna being blocked by buildings, but all the same, he was much weaker than other stations, which made me go out to see if there was anything unusual about the atmosphere.
Well, there certainly was! Whilst it was too dark to see land, stray light from street lamps was being refracted in a really odd way. It would have been nice to see what effect this would have had on the landscape, but sadly, it had all dispersed by this morning. The eerie lights came just as thick fog, which had affected UK travel all day, was being moved away by a slowly strengthening easterly wind (right to left in the image.)
There seems to be a kind of wave pattern set up in a low layer over the sea. This is not unusual, often being the result of shear disturbance of an inversion, such as when calm conditions are beginning to be blown away. Even without such disturbances, you can often see the surreal 'Fata Morgana' super refraction quite often, which also enhances propagation.
The lights are pretty odd, seemingly being lensed. It may be that the weak 2m signal was just in the wrong place, relative to the waves that were probably lensing radio signals as much as they were doing so for light.
Whatever the exact details, it was a good night on 2m!
Last night, idly twiddling about on 2m, I started hearing some Northern Irish stations coming in. Then some of the marginal repeaters were easily accessed. Within a few minutes, I was having easy simplex QSOs with both the south and north of Ireland.
 |
| Peculiar, wave-like features refracting light from the IoM. Douglas is on the right. The lights along the silhouetted hill are local, and not involved in the refraction feature. |
Strangely, one caller from the Isle of Man was pretty weak. He did say something about his antenna being blocked by buildings, but all the same, he was much weaker than other stations, which made me go out to see if there was anything unusual about the atmosphere.
 |
| Detail of the refraction. |
Well, there certainly was! Whilst it was too dark to see land, stray light from street lamps was being refracted in a really odd way. It would have been nice to see what effect this would have had on the landscape, but sadly, it had all dispersed by this morning. The eerie lights came just as thick fog, which had affected UK travel all day, was being moved away by a slowly strengthening easterly wind (right to left in the image.)
 |
| Large waves in an inversion layer being disturbed by shear from a developing but slight wind just above, as seen January 16, 2012, looking SW from north Anglesey (again, an easterly wind.) Contrast enhanced image. |
 |
| Waves in sea fog/low cloud, looking towards IoM, July 22, 2013. This kind of disturbance was probably responsible for the strange refraction of streetlights in the earlier images. |
There seems to be a kind of wave pattern set up in a low layer over the sea. This is not unusual, often being the result of shear disturbance of an inversion, such as when calm conditions are beginning to be blown away. Even without such disturbances, you can often see the surreal 'Fata Morgana' super refraction quite often, which also enhances propagation.
 |
| Fata Morgana affecting the landscape of the Isle of Man on August 10, 2012. |
The lights are pretty odd, seemingly being lensed. It may be that the weak 2m signal was just in the wrong place, relative to the waves that were probably lensing radio signals as much as they were doing so for light.
Whatever the exact details, it was a good night on 2m!
Monday 2 November 2015
It's 'K' for Cornwall - but only for a year.
After what can only be called a terribly sorry tale, Cornwall - which was last year awarded formal National Minority Status - has been allowed to use the 'K' secondary locator. But only for a year.
The RSGB and OFCOM have, to most minds, handled the whole 'K' for Kernow bid badly. The RSGB, whilst giving signals that it supported the bid, and who handled its making to OFCOM, can be seen from documents released under FoIA to have immediately lobbied against it. Most comments left online suggest that it may have been a vocal miority of contest-avid operators that swung matters against Cornwall at the RSGB.
OFCOM have now acceded to a request that the 'K' secondary locator be allowed for the whole of 2016. This is a step in the right direction, but does highlight the needlessly political and adversarial nature of this whole, actually very minor issue.
OFCOM continues to claim that it has no policy to award permanent secondary locators. This is rather odd, because it perfectly well allows the use of several other regional locators, which themeselves appear to have arisen and been accepted into law simply on the basis of convention dating back to the 1930s, and not due to any policy or lack thereof.
The RSGB has also attempted to apply spin to the whole locator business, leaving it with a lot of yellow stuff on its face. For example, it advanced the view that regional locators were only allocated to those areas with their own governments or similar arrangements. This is readily disproven, because power only began to be transferrred to regional assemblies, and then governments, towards the very end of the 20th century, when regional locators had already been in use for decades. I'm not sure when the 'C' alternative to 'W' came into effect within Wales, but it hasn't been that long, and so again, it seems that OFCOM isn't quite telling the right story when it claims it can't mess about with regional locators.
This was the straw that broke the camel's back for me, when I decided the RSGB and OFCOM had firstly bungled its handling of the whole thing, then applied entirely spurious and, frankly, wrong arguments to try and recover face.
I hope the year-long use of the 'K' RSL is very successful. Indeed, it would seem impossible that it won't be. Let's also hope it's a wedge into a permanent allocation.
On a final note, one wonders whether there is in fact any legal prohibition that can be backed up with prosecution on simply going ahead and using the 'K', or any other RSL?
The RSGB and OFCOM have, to most minds, handled the whole 'K' for Kernow bid badly. The RSGB, whilst giving signals that it supported the bid, and who handled its making to OFCOM, can be seen from documents released under FoIA to have immediately lobbied against it. Most comments left online suggest that it may have been a vocal miority of contest-avid operators that swung matters against Cornwall at the RSGB.
OFCOM have now acceded to a request that the 'K' secondary locator be allowed for the whole of 2016. This is a step in the right direction, but does highlight the needlessly political and adversarial nature of this whole, actually very minor issue.
OFCOM continues to claim that it has no policy to award permanent secondary locators. This is rather odd, because it perfectly well allows the use of several other regional locators, which themeselves appear to have arisen and been accepted into law simply on the basis of convention dating back to the 1930s, and not due to any policy or lack thereof.
The RSGB has also attempted to apply spin to the whole locator business, leaving it with a lot of yellow stuff on its face. For example, it advanced the view that regional locators were only allocated to those areas with their own governments or similar arrangements. This is readily disproven, because power only began to be transferrred to regional assemblies, and then governments, towards the very end of the 20th century, when regional locators had already been in use for decades. I'm not sure when the 'C' alternative to 'W' came into effect within Wales, but it hasn't been that long, and so again, it seems that OFCOM isn't quite telling the right story when it claims it can't mess about with regional locators.
This was the straw that broke the camel's back for me, when I decided the RSGB and OFCOM had firstly bungled its handling of the whole thing, then applied entirely spurious and, frankly, wrong arguments to try and recover face.
I hope the year-long use of the 'K' RSL is very successful. Indeed, it would seem impossible that it won't be. Let's also hope it's a wedge into a permanent allocation.
On a final note, one wonders whether there is in fact any legal prohibition that can be backed up with prosecution on simply going ahead and using the 'K', or any other RSL?
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