I like the idea of SDR radio. I even like what it delivers - provided it does actually work.
I have a very simple RTL SDR box that is widely available on the internet for a reasonable price.
Using SDR#, this dongle was a bit of a headache to install, but it did eventually come home and it was pretty sensitive, to be fair.
After a few weeks, the software simply won't work any more. Nobody really seems to have a coherent solution, and none I've tried have worked.
I then came across SDR-Radio, which looks very swish. After downloading a fairly big 89MB, given that I have a monthly 15GB allowance (living in the countryside is not for those addicted to the internet!), it reported a driver file missing.
To try and resolve this, off I went to the Microsoft website to download the necessary Visual Studio and C++ updates. After a few minutes, it was clear the updates would be very big - probably several hundred MB.
At this point, I had it reinforced in me that the reason why I like 'rice box' radios is that you just switch them on, and they work. If they break, it's usually pretty simple to repair. You can update the firmware over the internet, if you like, but it's often not critical.
Some, of course, like playing with computers all day. I don't, and I certainly don't like the sheer complexity of trying to resolve what might be wrong, only to find the same damned error message at the end of it all!
So, whilst I appreciate the benefits of SDR, the disbenefit is being wedded to an external computer and all the software updates. Despite all the patronising looks from IT people, the fact is that computers remain tools that far too often fail to do what they should in a sensible and stable way.
A rice box for me, every time!
UPDATE: I like it when someone else has produced flawless software that proves me wrong on the possibilities of SDR. I eventually came across Cubic SDR, which has none of the above problems. What's more, it provides much better signals than SDR# was giving. For example, an RAF base about 7 miles away was barely audible on SDR#, whilst the audio and signal strength are full strength through Cubic SDR.
Wednesday, 30 September 2015
Monday, 28 September 2015
12m Opens!
After what seems like a very long summer absence, 12m came back to life in no uncertain terms last evening - although few have realised it yet.
Just after 17:00UT, a strong signal came across on JT65A at 24.917. Turned out to be WA6JBZ, hitting my 3 ele LFA Yagi at -01dB. Given that he was using 25W into a G5RV, the band was certainly very open!
A few minutes later, I caught a ZF1 and a VE6, both good signals.
So, it's certainly looking like good autumn conditions on 12m at last. Now all we need is some more operators to come on board!
Once again, the futility of signal reports was demonstrated in the report I received from WA6, which was 9dB weaker than that handed out to a G5RV operator. Some might rush to say something's wrong with my antenna. In fact, it's a phenomenon repeated daily, often when I'm the only station folk can hear, especially in the well-populated US. It's a product of little gain and, often, poor antenna environments on the receiving, and not the transmitting side.
Just after 17:00UT, a strong signal came across on JT65A at 24.917. Turned out to be WA6JBZ, hitting my 3 ele LFA Yagi at -01dB. Given that he was using 25W into a G5RV, the band was certainly very open!
A few minutes later, I caught a ZF1 and a VE6, both good signals.
 |
| 12m, now open. |
So, it's certainly looking like good autumn conditions on 12m at last. Now all we need is some more operators to come on board!
Once again, the futility of signal reports was demonstrated in the report I received from WA6, which was 9dB weaker than that handed out to a G5RV operator. Some might rush to say something's wrong with my antenna. In fact, it's a phenomenon repeated daily, often when I'm the only station folk can hear, especially in the well-populated US. It's a product of little gain and, often, poor antenna environments on the receiving, and not the transmitting side.
Tuesday, 22 September 2015
Mugabe Land Heralds Start of 12m Season!
Yes folks, if, like me, you enjoy 12m and the great DX often found there, the band has started to open these past days.
This afternoon, Z21MG (Zimbabwe) was operating a huge pile-up in superb 59 conditions. I was glad to bust the noise and get my call in. The lack of calls from Zimbabwe is probably all down to those damned white people, if you're of a Mugabeian bent.
So, dust off your 12m stuff and start calling!
 |
| President Professor Doctor Robert Mugabe PhD DFC and nine bars. Still allowing ham radio, apparently. |
This afternoon, Z21MG (Zimbabwe) was operating a huge pile-up in superb 59 conditions. I was glad to bust the noise and get my call in. The lack of calls from Zimbabwe is probably all down to those damned white people, if you're of a Mugabeian bent.
So, dust off your 12m stuff and start calling!
Friday, 18 September 2015
'QST' - How Refreshing!
Regular readers - should there be any - will know that, in days gone by, I have been a bit of a moaner about the RSGB. Some of this moaning was justified - there has been plenty going wrong at the RSGB in the fairly recent past, after all.
But some of it was driven by frustration that it didn't really give anything much, save for the magazine, in return.
Eventually, and with no pleasure at all, gave up on the RSGB, largely because it seemed to have given up trying to improve the image and lot of the UK amateur.
For example, I suggested to the society some time ago that it ought to more energetically push press releases about the more interesting aspects of ham radio onto the media. The media, after all, love zero-effort press releases for padding-out their programmes and pages. I got a response that said a PR officer was being appointed, and that all looked rosy in that regard. A year later, you'd be hard pressed to find any online record of a successful press release from the RSGB. This morning, I still couldn't find any. It seems the RSGB is happy being quiet in the background, seemingly too stuffy to engage with the real world that prefers to play with tablets than HF transceivers.
So, I joined the ARRL. Having now received a few months worth of 'QST' and member benefits, I can say the ARRL gives you a really clear and strong sense of being a member of something bigger. The magazine is much more substantial, even if there are more adverts(!) and has far more interesting articles, written in a style that isn't dry, complex and dull, as so often is the case in 'RadCom'.
Simple things make all the difference. Engagement is one. I get very regular e-mailed updates on who is running what DXpedition, should I want to spend an hour shouting to get attention. I get a callsign@ARRL.net email address, which is very handy. I can read QST digitally if I want (though I never do), and the printed version arrives bang on time, without delay, every month. The articles teach me something practical every month, and in a way that suggests the ARRL want to include, not exclude you.
There is so much more of a community spirit in US ham radio. Often something of a bemusement for the UK, the 'emergency comms' aspect is very much to the fore, with few accepting the UK authorities' very wrong-minded views that you now only need a mobile phone in a widespread emergency.
Then you have the ARRL working hard over a long time to make the Parity Act a legislative reality. This essentially aims to recognise ham radio as a service of use to the nation, and that cannot be degraded by the ever-increasing numbers of Home Owners Associations that aim to ban even the slightest hint of an antenna.
Contrast this against the RSGB's position of having all but given up on trying to change the planning system to improve matters for hams in the UK, who only ever seem to get more, and not fewer, restrictions and intolerance placed upon them.
So, whilst the ARRL won't (yet) be changing much legislatively in the UK, it does at least offer an alternative sense of being part of the ham community, and one that is very much well done, I have to say.
But some of it was driven by frustration that it didn't really give anything much, save for the magazine, in return.
Eventually, and with no pleasure at all, gave up on the RSGB, largely because it seemed to have given up trying to improve the image and lot of the UK amateur.
For example, I suggested to the society some time ago that it ought to more energetically push press releases about the more interesting aspects of ham radio onto the media. The media, after all, love zero-effort press releases for padding-out their programmes and pages. I got a response that said a PR officer was being appointed, and that all looked rosy in that regard. A year later, you'd be hard pressed to find any online record of a successful press release from the RSGB. This morning, I still couldn't find any. It seems the RSGB is happy being quiet in the background, seemingly too stuffy to engage with the real world that prefers to play with tablets than HF transceivers.
 |
| So much more enjoyable than 'RadCom'. |
So, I joined the ARRL. Having now received a few months worth of 'QST' and member benefits, I can say the ARRL gives you a really clear and strong sense of being a member of something bigger. The magazine is much more substantial, even if there are more adverts(!) and has far more interesting articles, written in a style that isn't dry, complex and dull, as so often is the case in 'RadCom'.
Simple things make all the difference. Engagement is one. I get very regular e-mailed updates on who is running what DXpedition, should I want to spend an hour shouting to get attention. I get a callsign@ARRL.net email address, which is very handy. I can read QST digitally if I want (though I never do), and the printed version arrives bang on time, without delay, every month. The articles teach me something practical every month, and in a way that suggests the ARRL want to include, not exclude you.
There is so much more of a community spirit in US ham radio. Often something of a bemusement for the UK, the 'emergency comms' aspect is very much to the fore, with few accepting the UK authorities' very wrong-minded views that you now only need a mobile phone in a widespread emergency.
 |
| An uphill struggle, but could only be dreamed of for the UK ham community. |
Then you have the ARRL working hard over a long time to make the Parity Act a legislative reality. This essentially aims to recognise ham radio as a service of use to the nation, and that cannot be degraded by the ever-increasing numbers of Home Owners Associations that aim to ban even the slightest hint of an antenna.
Contrast this against the RSGB's position of having all but given up on trying to change the planning system to improve matters for hams in the UK, who only ever seem to get more, and not fewer, restrictions and intolerance placed upon them.
So, whilst the ARRL won't (yet) be changing much legislatively in the UK, it does at least offer an alternative sense of being part of the ham community, and one that is very much well done, I have to say.
Thursday, 10 September 2015
EH Antenna
Well, just when you thought there were no more antenna experiments to conduct, I've come back to the EH antenna!
If you look up the EH online, you will find most rubbish the whole antenna concept, saying it simply doesn't work. A few have gone to great lengths to measure, analyse and assess the antenna, concluding, similarly, that it's a dud.
Compare that with some operators who claim the complete opposite: that, whilst small and perhaps less capable than a full-sized conventional antenna, it does work, and significant numbers of QSOs, even DXCC awards, have been conducted with them.
Even a leading member of the UK ham community has built and tested an EH, finding he was "pleasantly surprised" with it, despite being placed in a non-ideal, roof space.
So, not ever being one to automatically believe others, I set off to the shops this morning to buy some cheap deodorant cans (with an awful, soap-like odour!) to cut up for the EH. These proved to be steel, which is not ideal, but are fine for a quick test.
The backbone of the EH is a PVC tube, but avoiding black ones, which are said to contain conductive carbon particles. I happened to have some white, 42mm tube lying around, which happened to be about the right diameter for an EH to cover the 15m band.
Now, there is some wire to place inside the EH's tube. Getting access to the inside of a long 40mm inside diameter tube is, well, impossible. I figured that by cutting a long slot down most of the length of the tube, leaving a few short gaps to maintain strength and shape, I could then get my fingers and a pair of long-nose pliers in there to fix things together. This proved to work well.
In fact, there is no need to use PVC to support the antenna components - they can just as well be screwed to a timber batten, which will make access and the whole construction a hell of a lot easier. You only need the tube to wind the tuning coils. Alternatively, you can still use the tubing, but arrange all but one of the wire connections externally, rather than internally; there is no reason other than cosmetic appearance to struggle with shoving it all inside a small tube!
So, it's simply a case of following one of the many, and not often the same kind of design found online, and hooking up. I was short of time when building this thing, so was amazed to find that even when thrown together, the native SWR was only 1:1.8. My ATU of course easily handled it down to 1:1, where I set it to work on 15m WSPR.
Sadly, there's been an awful lot of solar activity the past weeks, so 15m is all but dead. What does seem clear is that the EH is hearing pretty well - it seems quite lively, akin to a 1/4 wave vertical. Until the band clears up, I can't say much more than that. When it's clear, I'll run the EH next to my vertical 15m delta loop, see how it shapes up. A test has, as you might expect, already been done with WSPR, this one at 40m, which certainly doesn't indicate the EH is a dud.
As to feedline radiation, there doesn't seem to be a significant amount; it is there, but then I can find that on any transmission line, if I shove an RF detector at full sensitivity right next to it. My RF meter indicates there is moderately strong omnidirectional radiation, with a pretty low peak of 10 degrees or less; I followed the 'DX' version in making this EH, so the radiation angle seems to support this description as correct.
Certainly an interesting antenna, and very easy and cheap to build. What's more, even the strongest winds will have no effect on it - a very big plus at this QTH!
UPDATE:
Whilst 15m remains almost dead, I have been able to conduct some more RF meter measurements on the antenna. As many have noted, and some calculated theoretically in the scientific literature, this antenna seems only to 'work' by virtue of feedline radiation. There appears to be almost no field strength from the cylindrical radiators, whilst there is strong radiation, even with the presence of a well-made balun, from the coax. This feedline radiation only became clearly apparent when I raised the antenna to 2m above ground, allowing a decent length of vertical line to reveal this effect. The previous 'low angle' conclusion was merely my meter picking up less radiation from a much shorter vertical section of coax.
So, it does appear to be a complete dud, after all - so much so that I'm not spending any more time or even poicket money resources on a lower band version.
If you look up the EH online, you will find most rubbish the whole antenna concept, saying it simply doesn't work. A few have gone to great lengths to measure, analyse and assess the antenna, concluding, similarly, that it's a dud.
Compare that with some operators who claim the complete opposite: that, whilst small and perhaps less capable than a full-sized conventional antenna, it does work, and significant numbers of QSOs, even DXCC awards, have been conducted with them.
Even a leading member of the UK ham community has built and tested an EH, finding he was "pleasantly surprised" with it, despite being placed in a non-ideal, roof space.
So, not ever being one to automatically believe others, I set off to the shops this morning to buy some cheap deodorant cans (with an awful, soap-like odour!) to cut up for the EH. These proved to be steel, which is not ideal, but are fine for a quick test.
 |
| Made in a hurry, but comes in at 1:1.8 SWR before any adjusting. |
The backbone of the EH is a PVC tube, but avoiding black ones, which are said to contain conductive carbon particles. I happened to have some white, 42mm tube lying around, which happened to be about the right diameter for an EH to cover the 15m band.
Now, there is some wire to place inside the EH's tube. Getting access to the inside of a long 40mm inside diameter tube is, well, impossible. I figured that by cutting a long slot down most of the length of the tube, leaving a few short gaps to maintain strength and shape, I could then get my fingers and a pair of long-nose pliers in there to fix things together. This proved to work well.
In fact, there is no need to use PVC to support the antenna components - they can just as well be screwed to a timber batten, which will make access and the whole construction a hell of a lot easier. You only need the tube to wind the tuning coils. Alternatively, you can still use the tubing, but arrange all but one of the wire connections externally, rather than internally; there is no reason other than cosmetic appearance to struggle with shoving it all inside a small tube!
So, it's simply a case of following one of the many, and not often the same kind of design found online, and hooking up. I was short of time when building this thing, so was amazed to find that even when thrown together, the native SWR was only 1:1.8. My ATU of course easily handled it down to 1:1, where I set it to work on 15m WSPR.
Sadly, there's been an awful lot of solar activity the past weeks, so 15m is all but dead. What does seem clear is that the EH is hearing pretty well - it seems quite lively, akin to a 1/4 wave vertical. Until the band clears up, I can't say much more than that. When it's clear, I'll run the EH next to my vertical 15m delta loop, see how it shapes up. A test has, as you might expect, already been done with WSPR, this one at 40m, which certainly doesn't indicate the EH is a dud.
As to feedline radiation, there doesn't seem to be a significant amount; it is there, but then I can find that on any transmission line, if I shove an RF detector at full sensitivity right next to it. My RF meter indicates there is moderately strong omnidirectional radiation, with a pretty low peak of 10 degrees or less; I followed the 'DX' version in making this EH, so the radiation angle seems to support this description as correct.
Certainly an interesting antenna, and very easy and cheap to build. What's more, even the strongest winds will have no effect on it - a very big plus at this QTH!
UPDATE:
Whilst 15m remains almost dead, I have been able to conduct some more RF meter measurements on the antenna. As many have noted, and some calculated theoretically in the scientific literature, this antenna seems only to 'work' by virtue of feedline radiation. There appears to be almost no field strength from the cylindrical radiators, whilst there is strong radiation, even with the presence of a well-made balun, from the coax. This feedline radiation only became clearly apparent when I raised the antenna to 2m above ground, allowing a decent length of vertical line to reveal this effect. The previous 'low angle' conclusion was merely my meter picking up less radiation from a much shorter vertical section of coax.
So, it does appear to be a complete dud, after all - so much so that I'm not spending any more time or even poicket money resources on a lower band version.
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