AmateurRadio.com

Bob Bruninga, WB4APR, has updated the APRS specifications to allow amateur radiation monitoring stations to report readings over APRS.

1. A new APRS symbol for a radiation monitor has been defined using the characters RH. Although this is an H symbol with an R overlay, Bob suggests that there is no reason why APRS clients cannot give this symbol a distinctive icon.
2. A new weather field X has been defined for reporting nuclear radiation levels. The format is Xxxx where the first two digits are the precision and the last is the order of magnitude in nanosieverts. So 123 is 12 * 10^3 nanosieverts or 12 microsieverts.

There are already websites that report radiation levels using proprietary software, for example Radiation Network (which only covers the USA.) But the ability to report this information using the APRS network using the infrastructure that has already been developed for reporting weather observations is an exciting development that will no doubt lead to some interesting constructional projects.

I had seen rumblings in various forums that the new Internet Explorer 9 caused problems for some websites so I thought that I had better install it for myself in order to check mine. The installation process itself was alarming. A window came up to say that various programs that included system functions were in use and had to be closed. I agreed, while making a mental promise to myself that if this f***s up my computer then I’m switching to Linux for good!

I also saw my security software disabling itself. If any other program from any other source did that I would bail out quick. It really is sheer arrogance on the part of Microsoft to expect users to allow an installer to do things that security common sense says it shouldn’t, just because the software came from Microsoft. I wonder how long it will be before the malware guys set up fake IE9 downloads which exploit the knowledge that the setup disables security to load bad stuff on a computer?

After the install was finished the computer had to be restarted. Windows just loves being restarted. I wonder how many millions of hours of productivity are lost every year waiting for Windows to restart after an update? But I was now ready to try Internet Explorer 9.

The first thing I spotted is that the embedded APRS maps from aprs.fi on my website and also the WOTA website no longer work. Instead of the expected map you get a message box that says: “Minimum usable map size is 200×100. Currently: 550×0.” This is something that has worked on every single browser on every computer platform until now. It is another example of Microsoft arrogance to release a browser that is incompatible with everything that went before, knowing that because so many people use their lousy browser website developers will have to change their sites to make them work with Internet Explorer.

On my QTH Information page where I had an embedded map from Google Maps showing an aerial view of the neighbourhood centered on my house, the map is replaced by a # and a pop-up panel appears at the foot of the page to say “Internet Explorer has modified this page to help prevent cross-site scripting.” I have no idea what that’s all about. I guess I’ll just have to dump the maps.

I gave up writing software except for my own use because Microsoft made it impossible for self-taught amateurs like myself to write programs that work on all the different versions of Windows. Now it seems they are trying to make it impossible for self-taught amateurs to create web pages. Why can’t they keep things simple, and if something worked why did they have to break it? Perhaps it’s time to reinvent those little badges that people used to put on websites in the 1990s, only this time the badge would say: “This website works best in anything other than Microsoft Internet Explorer.”

I have never had a JT65A contact on 30m. This is surprising. The 30m band is the most popular band for the WSPR mode which has demonstrated that it provides good propagation 24 hours a day. The trouble is that there is nowhere for JT65A to operate. The JT65-HF software frequency menu offers two choices for VFO frequencies: 10.139MHz and 10.147MHz. But the former will cause interference to WSPR and have you fighting it out with a phalanx of PSK signals and the latter conflicts with the frequencies used by APRS packet and other digital networks.

To those who wonder why you can’t just find a clear frequency and operate I would point out that this doesn’t work with weak signal digital modes. Not only will users of other modes not know you’re there and call on top of you, but the DX you hope to work won’t be able to find you either. So it’s important to have a frequency of operation that has a good chance of being clear, where other users know to listen.

From recent discussions it appears that the two previously mentioned 30m frequencies were chosen in a desire to find a place to operate that fits in with the IARU Region 1 and Region 3 bandplans. In the USA (which is Region 2) narrow band digital modes can use 10.130-10.140MHz but in the rest of the world the area up to 10.140MHz is allocated to CW.

I have long believed (and have probably written before in this blog) that it is absurd to have different bandplans and different rules for different parts of the world because radio waves don’t stop at national boundaries. I suspect that the allocation of just 10kHz for digital modes was made back in 1979 when the 30m was first allocated to amateurs, when the only digital mode was RTTY. Since then, and especially in the last ten years or so, there has been an explosion in the number of digital mode users (due to the increasing use of computers) as well as a proliferation of different digital modes. It is time the band plans were updated to reflect that.

I think the bandplan for 30m in the rest of the world should be brought into line with that in the USA. I have nothing against the CW mode but if 30kHz is enough for US amateurs to get by with then the rest of the world can also manage with 30kHz.

JT65A is a wonderful mode, and JT65-HF by Joe Large W6CQZ is a wonderful program that makes it enormous fun to operate. True, the mode only allows the exchange of signal reports, though a very brief amount of extra information (such as power and antenna) can be sent in a custom message. But so many contacts using other modes also only result in the exchange of such limited information. On the other hand, there is a certain magic in seeing faint musical tones sent by a faraway station translated into a message on your screen. Many people have said that JT65A is addictive. I agree.

If there is one problem with the mode, it is that the 50 second transmit cycles where nothing is decoded on to the screen until the end makes it easy for your attention to wander. I’m ashamed to admit it, but many is the time someone has replied to my calls and I missed it because my mind was elsewhere. So I was really pleased to discover an add-on for JT65-HF written by Laurie VK3AMA called JT-Alert. One of a pair of add-ons he has written (the other is a kind of macro tool for custom messages) it watches the decoded text and sounds an audible alert when a CQ call is received or when a station replies to your call. You can have different sounds for the two alerts, and the audible alert is optional and can be disabled. The tool can dock to the bottom of the JT65-HF window (as in the screenshot above) so the two function as one program.

I have been monitoring for activity on ten metres, which is dead most of the time. It would get pretty boring sitting in front of a blank window for hours at a time but I have set the CQ alert to a loud klaxon which will bring me running to the shack from wherever I am in the house if/when a call on 10m is received. It’s a really useful tool (though it does get a bit annoying when working on 20m and my XYL isn’t so keen on it either!)

I made a number of nice contacts on 20m using JT65A today, including CO2VE (Cuba), PJ2MI (Curacao) and LU6AM (Argentina). I also worked a fellow blogger, David K2DBK. Unfortunately my custom message to David didn’t get sent as I got caught by a quirk in the JT65-HF program that was pointed out to me later by members of the JT65-HF support group. Apparently if you start a message with 73, those two characters are sent as a special shorthand sequence and the rest of the custom message is ignored. I had actually read that in the documentation, but I’m afraid due to the onset of senility RTFM often isn’t the answer as I FTFM (Forget The Frigging Manual) immediately after I’ve read it. Oh well.  🙁

It was a fine afternoon and I needed some exercise so I took the VX-8GR and the Albrecht 10/12m handheld and went for a stroll over Watch Hill. I put out a call on the 2m FM calling frequency and was answered by Jim, G3XPD, a few miles away. I asked if he could QSY to 28.500MHz SSB and he said he could, so I was able to make my first contact with the new radio.

When I first heard Jim call on 10m his audio was clear but very weak. This was puzzling when he told me he was hearing me quite well and was running 100W to my 4W. Eventually I realized this was due to the RF gain setting of the Albrecht. It is accessed via a few button presses, effectively on a menu, so I had left it as it was set by default. This clearly made the gain very low. After winding it up to maximum (see, I’m turning into a CBer!) Jim’s modulation was rattling the loudspeaker. No shortage of gain there, for sure.

The receive audio was very clear. Jim commented on some wind noise on my transmissions, which I was able to tame by changing position so the internal microphone was shielded by my head. I didn’t ask if he could hear any FM on my SSB modulation and he didn’t mention it. That’s good, as it suggests the problem isn’t noticeable enough to prevent making contacts and there is no urgency to try the modification that is supposed to cure it.

The main problem would seem to be tuning the radio on SSB. The Albrecht AE2990AFS is basically a CB radio designed to work on fixed 10kHz channels, even though it does have dedicated ham band modes. The tuning steps of the radio are 10kHz just like a CB radio. You can press a couple of buttons and select 500Hz steps but you can’t tune the band this way. You can tune in 500Hz increments up to just before the next 10kHz multiple then the VFO rolls back to where you started.

There is a clarifier or RIT control which is designed to tune in stations that are slightly off the 10kHz channel. It’s range is something like +/- 5kHz so it is quite touchy. There is no centre detent to mark the off position. What this all means is it’s quite hard to tune the band looking for signals and if you do tune someone in the chances are you’ll call them off-frequency.

A better solution, in my opinion, would be to dispense with RIT and make the clarifier change both the transmit and receive frequency. But if it was possible to do that one wonders why the manufacturer didn’t. I imagine that the control works by pulling an oscillator using a varicap diode so there is a risk of making the FM problem worse under the varying load conditions of SSB transmission. But if it could be done without affecting the transmitter frequency stability that would be a mod worth doing.

In the wake of the Japanese nuclear disaster there has been a surge of interest in interfacing Geiger counters to home weather stations so that radiation levels could be monitored via APRS. When you think about it, it seems a very good idea. Even if the measurements were not of lab grade accuracy, they would be good enough to show what was going on. It could avoid unnecessary panic – and equally make it impossible for officials to hide the existence of a radiation leak – if data from a network of amateur radiation monitoring stations worldwide was publicly available. This could be a real application to make APRS relevant even to the general public.

A standard for representing radiation measurements in APRS weather packets is being worked out as I write. The question is how to interface a radiation monitor to an APRS system and what hardware is needed to measure the radiation? Unfortunately, if not surprisingly, the final bid price of dosimeters on eBay has gone through the roof in the last couple of days. But in any case they all seem to be standalone instruments with no computer interface. I don’t know if a homebrew device would be possible, given that calibration would be needed, but if someone could develop one I think it would be a popular project.

Like anyone with an ounce of compassion, Olga and I have been concerned about the welfare of the people of Japan. But it is becoming clear, at least to me, that most of the anxiety we initially felt about a nuclear catastrophe occurring in the country has been caused entirely by irresponsible and sensationalist reporting by the western mass media.

Scrolling news headlines screamed about fear of meltdown even while nuclear experts on the same channels were explaining how, due to the design of the reactors, this wasn’t likely. Fear has been generated over increased radiation levels in Tokyo causing many expatriates to flee home, many on the advice of their own western governments. But whilst reporting these increased levels, the news media have not bothered to put them into context, such as how the amount of radiation compares with that received on the flight home to London or on a holiday in Cornwall in the south west of England, a place where the naturally occurring level of radiation is so high that nuclear plants cannot be built there because they would exceed the legal radiation limits before they even started.

Yesterday, apparently, the Italian relief agency did a test for radiation on the roof of the Italian embassy in Tokyo and got a reading which is lower than the usual reading in Rome! The problems with the Fukushima reactors are almost a non-event compared to the tsunami which has displaced half a million people and wiped whole towns off the map. If the rest of the world wants to help Japan it should get a grip and focus on the real disaster.

In my search to try to find out what is really going on I have found a couple of blogs which I have added to my blogroll. The first is A Brasspounder’s Cafe by Leo, JJ8KGZ. He has just begun to write about his experiences during the earthquake last Friday. The second, The Intercultural, is written by a British academic working in Tokyo. The author is not a ham at all, but the blog is very well written. Finally I have added the blog of Atsu, JE1TRV which is called CW4EVER. He hasn’t written much about the disaster and his interests are a bit different than mine but my blog was already in his blogroll which is good enough for me to add his to mine!

Meanwhile we continue to think of the people of northern Japan, and especially the 50 heroes struggling to regain control of the power plants at Fukushima, and hope that things start to get better for the Japanese people very soon.