AmateurRadio.com

Last weekend was the first really warm sunny weather of the year. Sunday 10th was the day of the Northern Amateur Radio Societies Association rally held in Blackpool. As we did last year, Olga and I booked a night in a Blackpool hotel and had a weekend away. As we drove out of the Lake District on our way south, an endless procession of cars crawled north on their way in. We wondered where they would all manage to park once they got there.

Just as last year, I failed to find anything attractive about Blackpool itself. The rally itself was worth the trip, and I managed to find a few bits I needed or hoped would come in useful, though this year I didn’t manage to find a bargain to match the brand new Motorola GP300 radio body for £1 I got last year. The same trader this year had some new VHF transceiver bodies from a now defunct manufacturer I had never heard of, but the price was now £2. He claimed that programming software was available on the web, but battery packs were unobtainable. They would perhaps be useful for someone wanting a cheap transceiver for APRS or something like that, powered by an external supply wired to the battery contacts.

I took a few items for the bring and buy but sold none of them. When I collected them in the afternoon the chap who retrieved them for me said that it was very quiet this year, people were looking but not buying.

I met fellow blogger Paul, M0XPD, whose multimode QRSS beacon was on display on his radio club’s stand. Paul also thought attendance was down on previous years. I guess that economic circumstances and the cost of petrol made many people decide not to go to the rally this year.

Once again Cross Country Wireless run by Chris G4HYG had a great location facing the bar and the entrance. Chris was running an APRS digipeater using Lynn KJ4ERJ’s APRSISCE/32 software and displaying his latest products including the APRS TNCs, bandpass filters and end fed antennas. Chris told me that business is very good and he actually sells a lot of his products to the USA. It is great to see a British ham radio manufacturer having success in the US market.

Sunday was also a gloriously sunny day and we returned home the same way we had come via the scenic route. To avoid Ambleside which is usually a traffic snarl-up we came over Kirkstone Pass. It is years since I had driven that route and I have probably never done it on such a nice day. The scenery was spectacular, though unfortunately it would have been too hazardous to stop and take any pictures.

A few years ago I read about a program called Radio Mobile which was supposed to be able to plot maps showing your VHF or UHF station coverage using actual terrain data. I downloaded it but couldn’t figure out how to get it to work so I gave up. A few days ago someone mentioned that it is possible to hook the program into an APRS server so I thought that I would try again. I was given a hint that for UK users the G3TVU Quick Start package was the easiest way to get Radio Mobile going.

The default setup is for a location in the Derbyshire Peak District so I followed the instructions on Changing Location to try to create maps centered on G4ILO. I got as far as producing an elevation map but was then baffled by the sentence: “Which can then be ‘Merged/Copy’ with a road map and ‘Kept in new picture’ to produce.”

James VE6SRV came to my assistance with an explanation in English: “On the menu select EDIT then in the drop down menu select MERGE PICTURES… F7. You’ll get a dialog box opened up. It will have a list of various sources on the left, detailed choices about the source in the middle and operation controls on the right.Try picking OSM, and then clicking DRAW. After the merge is complete, you’ll be asked how you want to keep the resulting image, or to discard it. The four options equate to SAVE, SAVE AS, LET ME LOOK AT IT FOR NOW, and TOSS IT. If you chose copy, the OSM tiles will overwrite the relief map. ADD, MULTIPLY, and BITWISE are 3 different methods of merging the shaded relief map with the OSM tiles. Depending upon the colours, and the type of output you want, you’ll need to play a bit with the choices to see how it looks for you. You can also play with contrast and brightness sliders to try and get the output just how you like it.” This was just what I needed, and after a bit of experimentation I soon had a road map of my area merged with the relief map showing the mountains.

The next step was to try to plot the coverage of my station on the map. I believe the default setup had a dummy base, mobile and hand-held station predefined but they were now outside my area and in any case I must have deleted them. Creating a “unit” for my own station was simple enough, but when I selected one of the tools to plot coverage the Draw button was disabled. Eventually I worked out that you have to have at least two stations (“units”) defined and they must both be members of the same network. The program will then plot the coverage for your station as received by a station of the same type as the other one.

I thought the coverage plots were rather optimistic judging by experience so I had to change some of the parameters and choose the “worst case” to get a plot that looked reasonable. This being VHF, it’s possible that the fact of my antenna being located in the attic could result in some degradation of the signal. I felt the default colouring of green for 3dB over noise or better and yellow for 3dB below noise to 3dB above didn’t give a realistic picture so I changed the colouring so that green depicts 10dB or more over noise and yellow shows between 0 and 10dB.

The first plot shows a wide area view:

Click to see the map full-sized. I did a second plot at a larger scale to show the local coverage in more detail:

The plot shows really clearly how my VHF range is limited by the surrounding hills.

Connecting Radio Mobile to an APRS server has limited use. The program doesn’t seem to handle objects very well so for example the GB3CA object put out by MM1MPB shows as MM1MPB and moves that station’s position. But it is a useful way to get other local stations into the system instead of manually entering their details.

The objects sent out by WOTA to show the position of a Wainwrights On The Air activation are shown as WOTA not the name of the object. The Radio Link option can be used to plot the path between two stations and estimate the received signal strength, as in this example showing the path between me and Phil G4OBK/P on the summit of Seatallan.

The estimated S9 signal strength is somewhat more than I actually received from Phil and I was running 50W not 10W. As mentioned earlier my antenna gain is also downrated over reality to try to get a more realistic picture.

Radio Mobile is a clever piece of software and it was interesting to play with it. It was quite hard work to get going, but it was useful to see how the nearby hills affect my VHF coverage.

Introduction:

• Indiana LinuxFest promo, March 25-27, 2011.

Announcements:

• Jerry Taylor, KD0BIK, has announced that he will be recording new episodes of The Practical Amateur Radio Podcast. Welcome back, Jerry!
• The Mid-America GNU/Linux Networkers Conference (MAGNet Con) has been postponed until Spring of 2012.
• Check out the Resonant Frequency podcast.
• Linux in the Ham Shack will be at the Indiana LinuxFest, March 25-27, 2011 in Indianapolis. Stop by and say hello. LHS will also be at the SouthEast LinuxFest and the Ohio LinuxFest.

Feedback:

• Ilan Rabinovitch writes to tell us about the Southern California Linux Expo (SCALE 9X), February 25-27, 2011.
  Thanks, Ilan. Sorry we couldn’t include this earlier.
• Kevin, KB9RLW, writes in response to Episode 51 that he agrees that Linux is a good fit for the amateur radio community for several reasons: added flexibility, security, and more choices. Even Windows 7 is still vulnerable and he points to a recent Sophos test. He keeps a WindowsXP virtual machine, in VirtualBox for those Windows applications he must run, though WINE usually works fine. He’s also a fan of The GIMP, OpenOffice, Inkscape, and Scribus. Good points, Kevin, thanks.
• Dave, KA6YQ, points us to instructions for running the DX Lab suite in Linux, which, unfortunately, just says that you can run their software in a Windows XP virtual machine, which isn’t the same as running it on Linux.
• Rick, K9AO, tells us of a native Linux EchoLink client SvxLink. Russ uses the Windows EchoLink program under WINE, but checked out the program. He tried building it from source, because he’s running Debian instead of Fedora, using the posted instructions, without success, but he’ll keep trying.
• Joseph C. sent a donation to the LHS Dayton Hamvention fund. Thank you very much, Joseph!
• Jonathan Nadeau of Frostbite Systems says that if you want to install the extra codecs in Debian, you must first add the multimedia repository to your sources list file (/etc/apt/sources.list). Add the repo, then install the codecs you want. Linux Mint Debian does much of this by default.
  Richard spent most of a day trying to uninstall Gnash and install Flash… without success. And it’s true that IceWeasel and IceDove are the same as Firefox and Thunderbird, but they are one release back. Richard prefers running the current versions.
• Russ tells us that by adding the following line to your /etc/app/sources.list file

  deb http://www.debian-multimedia.org testing main non-free

  and then doing an apt-get update, you’ll be able to install the non-free codecs.

• Russ and Richard then talk about removing Gnash:

  dpkg --remove --force-all gnash

• Russ recommends GhostBSD if you’d like to play with BSD.
• John, EI7IG, writes that Episode 53 was a “cracker” and that he’s a fan of fldigi, too. He also tells us of APRSISCE32, an APRS client for Windows written by Lynn, KJ4ERJ. John has been running IPV6 in the shack and points us to this article by Geoff Huston. Thanks, John.
• Larry Bushey and Tom Chaudoir of the Going Linux podcast send their regards.
• Russ gives an impromptu review of the Linux Reality podcast by Chess Griffin.
• LHS is a sponsor of the upcoming Indiana LinuxFest, and Lord D. sent his appreciation.
• Mogens, OZ1AKN, asks for help on a couple of topics.Question: Is it possible to automatically start a program under WINE?
  Russ responds with:To make a program under WINE start at boot, look at /etc/rc.d/skeleton for a sample. Copy the skeleton file to the name of the WINE app you want to start, then edit it to start whatever you want to start, such as /usr/bin/wine/echolink.If you want a program to start when the X session starts, click:
  menu -> system -> preferences -> statup applications -> Add a startup app
  In the dialog, give it a name and add the command: /usr/bin/wine <application path>

  Question: How do you reinstall Windows in a dual-boot setup?

  Russ responds with:

  It’s easier to install Windows first, then Linux, as the Linux boot loader will automatically detect Windows and include it in the boot menu. If you install Linux first, then Windows, Windows will overwrite the Linux boot loader.

  Otherwise, if you’re trying to repair a dual-boot system, try booting with a system rescue CD to repair GRUB.

  Google “linux boot ntldr ” to find instructions to tell the Windows NTLDR to also boot Linux.

• Tom H. sent a donation to the Dayton Hamvention fund. Thanks, Tom!
• Frazer writes that the LHS Facebook fanpage seems to be geoblocked in Canada. (Russ has fixed the problem. Thanks, Frazer.)
• Jim, KG9EQ, discovered the podcast while searching for QSSTV and wrote to share his appreciation for the website. Thanks, Jim.
• B.B. in the chat room asked if Jerry Taylor has resumed the Practical Amateur Radio podcast. (Richard’s comments were recorded before Jerry resumed recording episodes.)
• Paul, KC9QYB, has resumed his Teen Radio Journey podcast.
• Brady and Rich recently released another episode of the Low SWR podcast.
• Finally, a note to the ICQ Podcast: We encourage Colin to talk more!

Contact Info:

• Contact Richard at [email protected], Russ at [email protected], or both at the same time at [email protected].
• Listen to the live stream every other Tuesday at 8:00pm Central time. Check the LHS web site for dates.
• Leave us a voice mail at 417-200-4811, or record an introduction to the podcast.
• Sign up for the LHS mailing list.
• Sign up for the MAGNetcon mailing list.
• LHS merchandise is available at the SHOP! link on Web site. Check out the Badgerwear or buy one of the other LHS-branded items at PrintFection.com/lhs or Cafe Press. Thanks!
• Thanks to Dave from Gamma Leonis for the theme music.

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 have to say this was probably the hardest episode to put together so far. I managed to not record the first 20 minutes of my side of the episode. Then there were bits from Episode #057 that needed to be put in. I recorded secondary items that didn’t match up with the original first take. And somehow I think I managed to get it all put together and make it make sense.

Hopefully we will see everyone at Indiana Linux Fest this weekend in Indianapolis. If you can’t make it, be with us in spirit. Thank you to our listeners for all your support. Please continue to help us get to Dayton if you can, and remember to tell a few of your friends about us.

73 de The LHS Guys

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.

A few weeks ago I did an analysis of the audio levels of different APRS radios and lamented the low level of the audio transmitted by the Yaesu VX-8GR. An Italian ham wrote to me enclosing a copy of a document he obtained from Yaesu showing how to increase the transmit deviation. I decided to give it a try. You can find a copy of this document in the Files section of the VX-8R Yahoo group, but I will describe the process here.

Note that performing this adjustment will increase the transmit deviation on speech as well. There is no way to increase the packet deviation independently. Note too that while you are in the alignment menu it is possible to change other settings as well by accident. This may be undesirable, especially if you don’t have the test equipment to realign the radio properly, so be careful and perform the adjustment at your own risk! Finally, note that these instructions will work only for the VX-8GR. There are instructions for accessing the alignment menu of the VX-8R on the web. They don’t work for the GR and these instructions don’t work for the R. I have no idea if any of the instructions work with the DR.

To avoid entering the alignment menu accidentally, Yaesu has made accessing it quite difficult. First you must enable the CW ID (main menu item 16) and program a password AH041M into it. The manual explains how to do this. You must then set the transceiver to single band mode on the A band, in VFO mode (not memory) on a frequency of 430.000MHz. Now switch the radio off.

Press and hold the HM/RV key and turn the VX-8GR back on. If all the above steps were carried out correctly the radio should start up in alignment mode showing the first alignment setting. Rotate the control knob clockwise a few clicks to select the MAX DEV adjustment, then press the V/M button to select it. A pointer symbol should appear to show that adjustment is selected.

The control knob now adjusts the deviation setting. Make a note of the original value in case you want to reset it, then turn it up to 254. Yes, I know this sounds like a CB “screwdrivers to the max” tweak but as you can see from the spectrograms below, even at that setting the packet deviation won’t quite match that of the Kenwood rigs. Press the V/M button again to exit the adjustment, then press HM/RV to exit the alignment menu. The radio will restart in normal operational mode. Don’t forget to clear the CW ID once you’re happy with the new setting.

The spectrograms below show the difference made by the adjustment, with the Kenwood TH-D72 shown as a reference.

 

As you can see, the peak deviation of the high tone is now within 1dB of that of the Kenwood, though the Yaesu still has more low-frequency roll-off. Nevertheless, this is as good as it gets with the Yaesu. If you still can’t hit the digis you think you ought to, perhaps you’d be better off with a Kenwood.

As I said earlier, this deviation adjustment makes your audio louder as well. You, your local hams or your local repeaters might not like this. The VX-8GR has a “Half Deviation” menu option which will reduce the deviation back to approximately what it was before this adjustment, but it works across the whole radio and not per band, so you can’t have the wider deviation only on the APRS band.

It is interesting to note that in the Yaesu alignment document the deviation alignment is performed at 435MHz. I found that the deviation on 70cm is higher than it is on 2m. This appears to be a consequence of the way the radio is designed, as there are not independent deviation adjustments for the two bands. But this does explain to an extent why the deviation on 145MHz is lower than it should be.

Where I live, 70cm is completely dead and 2m is quiet so we can operate using 25kHz channel standards with no problems. Therefore I have not found this adjustment to cause any adverse effects and it certainly has improved the reach of my APRS packet beacons. Your mileage may vary.