AmateurRadio.com

I received an email this morning (actually it was posted in my guest book of all places, though I have since deleted it) from a ham named Mike informing me that the program Morse Machine on my website contains a Trojan. It’s a false alarm, and I’ve had it before. I blogged about it a few months ago, so I pointed Mike to that blog posting by way of an explanation.

Mike didn’t mention which scanner gave the false alarm but I was able to deduce from the copy of the scanner log he posted that it was ClamWin, a free GPL virus scanner. Now I’m a fan of free software and in fact experimented with ClamWin a few years ago, but the honest truth is it barely deserves to be called a virus scanner. A bunch of enthusiasts working in their spare time do not have the resources to develop a commercial quality virus scanner and I don’t think anyone should be depending on such a program to detect viruses, especially as there are plenty of free (though not GPL) alternatives that are much better.

After Mike read my blog post he replied:

“I downloaded your CW learning program for my grandson, trying to help steer him into Ham Radio.

With the preponderance of malware out there, I find your opinions a bit disingenuous if not downright arrogant. i.e. the “Im ok and your not” attitude.

You could would write your own installer like I (and others have) and stop the complaints (and your belly aching) rather than baiting users with KNOWN problems.

That’s my opinion, although I will concede you have the right to yours and say and do what you want :)”

My opinion is that I don’t see why poorly written virus scanners should become my problem? Why should I rewrite the installers for all these programs, which doubtless will then be accused of containing a different Trojan? I don’t make these programs available for money and no-one pays me for my time working on them. If making them available means I am obligated to spend more of my ham radio time supporting and updating them because of issues like this, the best thing from my point of view would be to remove the programs entirely.

Nor do I see why I should have to put up with complaints like this just for making available programs I’ve written in the hope that others would find them useful. Of all the things I’ve done on this website, only the software results occasionally in emails that spoil my day and make me angry.

I don’t have time to delete the software section at the moment but I will when I get around to it.

Yesterday Kevin GW0KIG downloaded Fldigi with the aim of trying to make some Olivia contacts. He had some success but wasn’t always sure which settings (width, number of tones) to use. He also found the number of different digimodes a bit confusing and wondered what the benefits of them all are. Well, Kevin, you’re not the only one!

The Fldigi online help has some information about the different modes. The website of MultiPSK also has some good descriptions of different modes, including the speed, bandwidth and minimum signal to noise ratio of most of them. Someone should probably take this information and summarize it on a website – unfortunately the domain confused.com is already taken.

Olivia appears to be the best performing of the multi-frequency shift keying (MFSK) modes, which should not be surprising as it is the most recently developed of them. That being the case, it might not be a bad idea for older MFSK modes that have fallen out of use to be banished altogether. There is no reason for every mode ever invented to continue to be an option on every digital mode program – it just creates confusion. The latest Fldigi beta (3.20) actually goes some way towards this by providing an option where you can specify which modes appear in the menu. The next step would be for the obsolete or little-used modes to be hidden by default.

Life on the digital modes would be easier if the commonly used modes each had their own place on the band where you could expect them to be used. PSK31, WSPR and JT65A all have their own “homes”, and Olivia also uses certain frequencies – or did until they were overrun by a certain other mode that is not available in the popular digimode programs and can’t easily be inter-operated with.

Solutions exist to help identify a mode being received, but they are hardly ever used. Both of the methods are supported by Fldigi and quite possibly by DM780 as well. One is video ID, as illustrated by the screenshot above. The software will transmit sounds to create letters identifying the mode at the start of a transmission. The other is RSID (Reed Solomon ID) in which the software transmits a signal that identifies the mode to the receiving software, which can then automatically switch to the correct mode.

There is clearly no need to use these IDs for commonly used modes like PSK31 or RTTY which can be recognized by sight and sound. That would just waste time. But for the various similar sounding MFSK modes it would be a big help if IDs were used. Fldigi runs on all platforms and it’s free, so there is no excuse for not using it and enabling the ID if you want to try some of these lesser-used modes. (Note: You really want the 3.20 beta in which the options for configuring the use of IDs have been much improved.)

Kevin, GW0KIG, has just written in his blog about struggling to brush up his Morse. He first learnt the code at the age of 19 and has “memories of a Morse code tutor program on a borrowed ZX81 computer (remember those?)”

I remember the ZX81 and its wobbly 16KB RAM pack very well. In fact, a Morse tutor was one of the first programs I wrote for it. I wrote an article for Short Wave Magazine which described the program, together with a Morse keyboard with programmable memory and a high-speed Morse sender for meteor-scatter work. It is amusing today to read my conclusion that “it is possible to program the ZX81 to create sophisticated memory keyers.” These primitive programs would hardly seem sophisticated today.

The article was published in the August 1982 issue of Short Wave Magazine. I kept a copy and you can see it here. I wonder if my program was the one Kevin used to learn Morse when he was 19? One of these days I might try downloading a ZX81 emulator and see if these old programs will run on it.

Another new digimode has made its presence on the airwaves. Called ROS, it uses spread spectrum techniques in a bandwidth 2.2kHz wide and offers a choice of two symbol rates, 16 baud and 1 baud. The latter will be of great interest to QRP operators as it is claimed to allow communication at signal levels of 35db below noise, which is better even than WSPR. ROS is an interactive mode, so you can type what you want and have a real QSO, unlike WSPR and the other JT modes that can only send a limited number of fixed messages. What’s more it isn’t an all-or-nothing mode like the JT modes, so you can receive a message that’s part garbage and use your own intelligence to correct the errors if possible.

An interesting feature of ROS is that the software will automatically send an emailed reception report to any transmitting station that includes his email address in his transmission. Quite how it achieves this I don’t know, since I don’t have an email client set up on my shack computer (I do all my email through Gmail.) So I was quite surprised after receiving my first ROS signal from G3ZJO running 1 watt on 40m to see him send “HI” to me on his next over (as you can see in the screengrab.)

This is yet another program that only recognizes the “default” sound card so I am once again receiving using the HB-1A transceiver and am unable to transmit using the mode.

The weak signal capabilities will no doubt make this mode of interest to the QRP fraternity as well as VHF operators working EME and troposcatter. I think the ability to receive an emailed reception report is also rather cool, and a bit more personal than seeing your signal spotted on a website.

However I do wonder what will happen once the massed hordes start using it on HF and begin cranking the power up to try to work further afield. There isn’t enough space on the HF digital mode bands for many simultaneous contacts to take place using a 2.2kHz wide mode.

I’m now listening on 14.101.0 MHz USB so if you try this new program and put your email address in your message you might get a report from me.

Chris, G4HYG, has just released a new Windows program called APRS Messenger which supports APRS messaging using the PSK63 mode. Various experiments made in the past suggest that this could give better reliability at low power levels than 300 baud packet which is normally used on HF. APRS Messenger also functions as an Internet gateway so any error-free packets received over HF are sent to the APRS-IS network.

An unfortunate limitation of the program at the moment is that it will only talk to the “default sound card” which on most Windows computers is the one used to play system noises, listen to Internet audio and video and so on. So I am unable to use it with my K3 at the moment. For test purposes I have connected my HB-1A QRP transceiver to my 30m antenna and fed the headphone output into the mic socket on the front of my PC.

I have decoded a few packets already, though many seem to contain some corruption. I am wondering why the little-used QPSK63 mode was not used for this application? As I understand it (and I could be wrong) QPSK63 takes up the same amount of bandwidth but incorporates some forward error correction that improves the likelihood of good copy compared with plain PSK63.

Chris has apparently agreed to talk with Lynn, KD4ERJ, about the possibility of making APRS Messenger work with APRSIS32. The possibility of using Lynn’s full-featured APRS client to send and receive APRS over HF using PSK is quite exciting.

By the way, if you are wondering why the screenshot shows a Mac program the reason is that I’m using an OS X theme under Windows XP!

Today we present Linux in the HAM Shack for the eleventh time. Because of a topic snafu we switched to a completely untested and radically different format for the program. However, in the words of esteemed author Douglas Adams: “Don’t panic.” We simply rolled the live feed into something resembling a roundtable discussion of Linux and ham radio related topics that we think listeners will find rather interesting and engaging.

That being said, because of the unusual format of the program some of the dialogue may seem a little strange. In most cases it can be explained as one of the hosts reading questions or reciting information provided by the live participants in the chat room at the time of recording. We also managed to wrangle a special third co-host for the middle portion of the program.

All in all it’s a wild and crazy ride. Thank you as always for downloading the podcast, and special thanks to those who helped us out by joining us for the live recording of the program. Please check the web site for the next time you can hear us record live and participate in the program yourself.

Enjoy this special edition of Linux in the HAM Shack and we’ll be back in a couple of weeks with a program on logging software, a review or two of CrunchBang Linux and much, much more.

73 de K5TUX and KB5JBV

After putting this off some because of the holidays and other obligations, Episode #006 is now hot off the press. This is the second in our two-part series on PSK31. In the first part, we looked at sound cards, rig control interfaces and the basics of getting a PSK31 software package installed on your Linux operating system.

In part two, we take a much closer look at two popular programs for operating PSK31 mode on Linux: gmFSK and fldigi. On top of that, we respond to listener comments and questions, talk about updates to the web site, and explain how you can be involved in the recording of Linux in the HAM Shack by listening to the live feed and interacting with us in the chat room.

Next up in Episode #007: Install episode! We’ll guide you step by step through the entire process of installing Debian or Ubuntu Linux on a machine to use in your HAM shack. If you join us for the live feed, we’ll even be able to answer your questions in real time.

Stay tuned, and please, keep the feedback coming.