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I have not been keeping up with the development of the controversial ROS digital mode as for reasons given in earlier posts I decided it was not something I wanted to use. However a recent post in the Yahoo digital modes group brought to my attention a development that seems rather alarming. The ROS software has recently included an anti-jamming switch the purpose of which is described as “improves rejection against strong CW and Beacons interferences.”

Polite usage of the amateur bands require that you check the frequency is in use before making a call so no-one should be jamming anybody. Furthermore, no-one should be using ROS in the CW or beacon sub bands. So what exactly is the purpose of this switch and why should anyone need it?

Perhaps an inkling of what may be going to happen can be drawn from some of the comments relating to the performance of the anti-jam switch, for example:

• “The New ROS/2000 passed the test successfully during the CW Contest last weekend.”
• “More test with the New ROS/2000 in other hostile environment. This time during a PSK63 Contest on Sunday.”

As I said all along (indeed, this was my original objection to the use of this mode) ROS is just too wide for use in the narrow digital allocations of the HF bands. There just isn’t the space for it, unless it remains a niche, occasionally used mode, which clearly its developer and supporters don’t intend it to be. As another comment in the ROS forum states: “The bands will fill up once people realize how good this mode is.”

The development of anti-jam techniques suggest that ROS is being readied to engage in war with users of other modes. When users can’t find a clear frequency they will just operate on top of other modes. The principal claimed advantage of the wide ROS mode is that it enables contacts to be made under similar weak signal conditions to JT65A but that it permits keyboard chats to take place rather than the basic exchange of signal reports and locators. So it appears that a vast swathe of spectrum space is going to be made unusable for other modes simply so that people can exchange brag files.

We need strict regulation of digital modes on the amateur bands. The days of gentlemen’s agreements are over. There are too many modes competing for limited spectrum space, and too many hams who aren’t gentlemen.

In the digitalradio Yahoo group a few people have been experimenting with APRS on HF using the robust ALE400 mode. I am interested in trying more robust modes for APRS and wish that someone would work out how to interface the new Winmor TNC to an APRS client. But as nobody has, I thought I would try to give this a go. Unfortunately this meant getting to grips with MultiPSK, a program that is something of a personal bête noire as whenever I have been tempted to try I have never been able to figure out how to use it. Today turned out to be no different.

I downloaded the latest version of the program, started it, and was presented with an unexpected screen for a digital modes program. After a few seconds of puzzlement I realized that this was the configuration screen. Normally with software you get the main screen and select configuration from a menu but MultiPSK is not as other software. Oh no. The author threw away the book when he wrote this program, the book in question being “Microsoft User Interface Guidelines.”

I managed among the bewildering array of buttons and options to find one to set the sound card, another to set the KISS TNC port that I would need and one that I presumed would set the serial port for PTT. As I couldn’t find an OK button I tried closing the window and MultiPSK itself closed. Completely. I tried again and realized that you have to click a large button marked RX/TX Window to get to the main operational screen. Bizarre!

The main screen contains another mind-boggling array of buttons and controls, but I did see a waterfall with noise scrolling down the screen, which looked encouraging. At least I’d managed to select the sound card correctly. After staring open-mouthed at the screen for fully two minutes I managed to spot a button marked ALE400, so I clicked it. I was now in ALE400 mode. At least, I think I was, though I don’t know how I was supposed to tell for sure.

One of the Yahoo group postings had mentioned that you needed to click a button marked “Aux. functions”. After some more searching I found this button it and clicked it and up popped another bewildering dialog box crammed with buttons. Hilariously, at the top is the caption “This panel opens with the Aux. functions button in the TX/RX screen.” Yes, I really laughed out loud when I saw that. If I didn’t know that how would I ever find it?

I spotted that some buttons on this new dialog were to do with APRS. I clicked one and a dialog popped up saying something about there being no map folder. So apart from being a digital modes program MultiPSK is trying to be an APRS client as well? The phrase “jack of all trades, master of none” sprang briefly to mind before I dismissed it as being uncharitable.

I clicked another button marked “APRS Transmit” and a strange notepad-style window appeared with the caption Error which said “No possibility to transmit your call and so APRS frame because there is no call in your personal data (button ‘Personal’).” The English wasn’t great but I could understand what it was trying to tell me. I closed the error dialog but although I could see several places that looked as if they were meant to have a call entered in them I couldn’t see anywhere marked “Personal.”

I did discover a documentation file to do with setting up APRS using ALE400. Unfortunately it is a .doc file and I don’t have Microsoft Word. I did try opening it in Wordpad which is what I normally use but it displayed several errors about graphics filters and opened the file without the all-important images. Google’s HTML view of the document couldn’t display the images either. Hello, anyone heard of PDF files?

Now I do feel a little bit guilty criticizing the work of a fellow amateur programmer. I’m sure the author of MultiPSK, Patrick F6CTE, is far more talented than I ever was in being able to implement all of these sound card digital modes. But when it comes to user interface design I’m sorry but MultiPSK sucks.

This has to be the worst user interface of any program I have ever encountered, by a long way – and at one time in my life I used to review software for a living. Its worst sin is that it uses buttons instead of menus and apparently has no context-sensitivity (or more specifically mode-sensitivity) so that you are presented with all of the available options all at once, which is not only confusing but wastes a lot of screen space. It is testimony to the delight that so many practitioners of our hobby take in doing things the hard way that so many people are willing to use this program to operate digital modes when there are so many better-designed alternatives.

Once again MultiPSK has been deleted from my hard drive without transmitting so much as a digit. If APRS over ALE400 is only achievable by those able to master MultiPSK then I’m afraid it will go nowhere.

My home made USB digital modes interface “SignaLink clone” has been completed. It has been in use for several days and is currently in use with my K2 for 30m APRS.

USBlink interface with cables for FT-817

I have written up the project on the G4ILO’s Shack website. See home-brew USB digital modes interface.

Peter, G4NKX, uncovered a can of worms the other day after encountering some unpleasantness by CW users in what has traditionally been the PSK segment of 40m starting at 7.035MHz. It appears that the 40m band plan in IARU Region 1 (Europe) has been changed, but nobody has been told, including the IARU.org website which still has copies of the old band plan coming up top in Google searches for “IARU Region 1 Bandplan“.

Under the current European band plan for 40m, CW now has free reign up to 7.040MHz, with narrow band digimodes from 7.040 to 7.050. So the start of PSK31 operation is now presumably 7.040MHz. However the bright sparks who sit in their ivory towers and decide this sort of thing clearly forgot about the real world in which people don’t find out about something unless it is shoved under their noses. People will operate where they hear other people operating, which creates a very powerful inertia against any form of change. These band plan changes came into effect on 29th March 2009, yet people are still in ignorance of them 18 months later. Where was the letter from the national society to each licensed amateur, informing them of the changes?

But more to the point, why change? It’s just a recipe for chaos and an opportunity for the band police to cause unpleasantness, just for the sake of an extra 5KHz for CW operators. It also now means that digital mode users in Europe must use a different part of the spectrum to those in the USA, making transatlantic digital DX impossible without incurring the wrath of the policemen. Frankly, I don’t blame PSK31 users for staying where they were and refusing to be shunted around by bandplan changes that don’t give them any benefits.

I’m somewhat confused about what the 40m USA bandplan is. The document on the IARU website for Region 2 shows narrow band digital modes starting at 7.035MHz. But I thought people in the USA operated PSK31 starting at 7.070MHz and other narrow band modes like JT65A at 7.075MHz? No wonder I have never heard any Stateside DX on digital.

Radio waves don’t stop at IARU regional boundaries so what is the point in having bandplans that put digital modes in different parts of the band in different regions? It just goes to prove that the powers that be who make these decisions think the only modes that matter are SSB and CW.

Several of my blogging compadres have written recently about using the JT65-HF software by W6CQZ so I thought I would give it another try to see if I could understand what all the fuss is about. This is not the first time I have tried the program. I tried it at the beginning of the year. In fact, it was the main reason for upgrading my shack computer because the old one could not decode the received signals quickly enough to give me time to reply to calls. But having got the new PC I found the mode rather uninvolving as contacts are made just by clicking buttons to send computer-determined reports and you can’t even tell which of the signals you can hear is the one you are replying to.

I decided to run the K3 at 5W into the dipole because the K2 was doing 30m APRS gateway duty on the magnetic loop and the two antennas are only a few feet apart. But there was no interference. I’m not sure how much power people normally use on this mode but I might try more next time. My new shack computer coped easily, decoding the received JT65A signals in a second or so despite the fact that it was simultaneously running two APRS gateways one of which was using TrueTTY and a USB sound card to decode the packet data.

I found a free spot on the waterfall, sent a CQ and two people immediately came back to me at the same time. I didn’t decode anything! I called again and this time three people replied! I sent CQ once more and this time the first two must have decided I was either deaf or an idiot which left just one signal on my frequency: OE1LIC, for my first contact of the day. My second CQ raised RZ6AUJ, Alex for another contact and that was all I had time for before dinner.

One of the features of JT65-HF is that it automatically links in to the PSK Reporter network so you can see all the stations you heard on a map and, even more interestingly, all those that heard you. I remembered this and popped up to the shack after dinner to grab a screen shot. As you can see, my 5W to an attic dipole was heard by two stations on the west coast of the USA, and I was only on the air for about 20 minutes! The small blob on the west coast is VE7IRA who was heard by me despite the appalling S9 interference I get on this band, which was reduced to about an S3 by the MFJ-1026 noise canceller using a PA0RDT mini-whip for a noise antenna.

I still find using JT65A on HF feels a bit odd but I can understand why it has become so popular, even addictive. It takes up little band space and doesn’t interfere with other band users unlike a certain R** digital mode. I said this before and didn’t end up doing it but I think I will spend a bit more time using JT65-HF to see what I can work and whether I can join the crowd of enthusiasts for this unusual digital mode.

One of the reasons I’m not endlessly filling my log with DX contacts is because I actually get more enjoyment and interest out of trying new things or just tinkering about. On Sunday I decided to try using my K2 – which has been redundant since the few mobile excursions I made earlier in the year when Olga was away – for HF 30m APRS. I connected it up to the magnetic loop. I didn’t have a spare sound card I could use for the packet modem, but the microphone input of the USB dongle I use for computer audio playback was free, so I set it up for receive only.

When I previously tried to use that USB audio device to decode HF packet via the AGW Packet Engine I had no luck at all. At the time, I concluded that this was due to 300baud packet being a higher speed mode than PSK31 and the USB device was somehow losing the information necessary to decode it. However it now appears that the reason it didn’t work before is because the AGW Packet Engine opens the device at a higher sample rate than most digital mode programs. For the last few weeks I have been using TrueTTY as a packet decoder and this uses a 11025Hz sample rate. I used TrueTTY to decode the audio coming from the cheap dongle and it appears to be just as sensitive as it was when the audio was coming from my best sound card.

This morning I tried listening on 14076kHz, the JT65A frequency, and decoded several stations despite the high noise level on 20m. So it seems to me that it is possible to use these cheap USB dongles for sound card digimodes as long as the software you use samples at 11025Hz. Some programs unfortunately don’t let you set the sample rate and may use a rate as high as 48000Hz. This is unlikely to work if my experience is anything to go by, so I still don’t recommend that you buy one of these cheap devices for digimode use unless you have a specific application in mind that you know it will work with.

I have now ordered another of these cheap USB dongles which I plan to make into a “DIY SignaLink USB” with the aid of the digital VOX circuit developed by Skip Teller, KH6TY. This will allow me to use the K2 for HF APRS, WSPR or other QRP activities using the magnetic loop, and free up the K3 for other purposes using the multiband dipole. In fact I will then be able to use four amateur bands and four different radios simultaneously if I want to!

The popularity of web videos and podcasts means that most ham radio enthusiasts who want to use sound card digital modes no longer want to dedicate their computer’s built-in sound card for that purpose. The usual solution is to buy a purpose made interface such as a RigExpert or SignaLink (expensive but highly recommended by all who own one) or an external USB sound card. However a great many people claim that the cheapest USB sound card “dongle” costing just 99p on eBay is good enough. Take it from me, it isn’t.

I have had several online discussions bordering on arguments with self proclaimed experts who claim that the sound chip in these cheapo “dongles” is exactly the same as the one in a £100 SignaLink USB interface so the £1 dongle must be just as good. I have no idea if they are right about the chip. What I do know is that when I played back a recording of very weak CW using one of these devices all I could hear was noise. And when I tried to use one of these devices to decode a fast digital mode such as packet, I decoded nothing at all, not a single packet, even though I could see the signal loud and clear on the waterfall.

I have tried a number of these cheap devices. I bought two of the cheap thumb sized “dongles”. One I threw away after seeing the noise it introduced on the waterfall. The second I bought thinking it would be good enough for computer audio, which it was, but had to throw it away when it failed after a week. I also spent a bit more on a slightly fancier sound card “dongle” which I currently use for computer audio, but which still displayed the inadequacies on weak signals and fast data modes that I have mentioned.

Finally I tried the device pictured above. It doesn’t have a brand name but can be readily identified from the picture and is advertised on eBay as something like “USB 6 Channel 5.1 External Sound Audio Card For Laptop”. It costs around £8.50 including postage from China. It comes in a small extruded aluminium case, has connections for SP/DIF input and supports sample rates of up to 48kHz so it would probably be suitable for basic SDR use. It has decoded every digital mode I have so far tried it with. And it’s small enough to build into your own box to make a DIY SignaLink.

It comes with a mini-CD containing a Windows driver. This installs a small mixer/control panel application that loads in the task bar and provides the usual control over the various sound effects. I used one of the start-up program managers (Autoruns) to remove it and find that it works perfectly well for my purposes without it, just using the standard Windows mixer settings. This is certainly preferable to the Creative SoundBlaster USB device that some people recommend which allegedly installs 200MB of junk on your hard drive.

I think this is probably the cheapest external sound device that is worth using for sound card digital modes. I’d be interested to know of alternatives, but please don’t recommend something unless you have actually done A/B comparisons with a known good sound card using weak signals, fast modes and different software packages. I hate to think of the frustration some people must have experienced following the advice of the self proclaimed experts, buying one of the £1 “dongles” and wondering why they can see a trace on the waterfall and can’t decode it.