Wednesday, 5 March 2014

Notes from the Shack - March 2014

Contesting isn't for everyone, but when we talk about ARRL Field Day as an emergency preparedness exercise it isn't just about establishing long distance communications in the face of widespread disaster, but operational readiness and reliability. As the recipient of the Coffee Pot Award for my first shot at being a band captain, I've seen how important it is to have a solidly reliable setup.

Mazes of Software

Over the holidays I used Ham Radio Deluxe to participate in a few phone and RTTY contests. The last of these was the RTTY Roundup, and 30 minutes into the contest I was so frustrated with HRD I quickly installed the N1MM logger, MMTTY and 2Tone. Setup took less than an hour and the result was a much better QSO rate, easy identification of dupes (for non-contesters, this is slang for duplicate contacts, not for operators who are easily hoodwinked), and flagging of multipliers. The sudden increase in efficiency let me log more contacts in the dozen or so hours operating the contest than in 24 hours of Field Day - not necessarily an apples to apples comparison but still encouraging.

In conjunction with N1MM I used HDSDR to find signals using a Softrock Lite II connected to the IF of my K3. HDSDR can't control N1MM directly and rather than try to hack a solution while the contest was running I didn't use it for rig control. This resulted in a fair amount of knob spinning to tune in signals but as they were so close together it wasn't a big deal even at the dial's most precise (i.e. slowest) setting of 200Hz per turn. The IF output is picked off prior to the radio's crystal filtering stage, so the narrowest filter (250 Hz) can be used to feed the RTTY decoders while still being able to see a 100 KHz wide swath of the radio spectrum.

The default display in the MMTTY and 2Tone RTTY programs is amplitude over frequency rather than a waterfall. In general I keep the filter narrow (250Hz) and it's more like regular tuning than just clicking the mouse on the signal you want. What the programs lacked in point-and-click was made up by the better decoding accuracy, integration with the logger (worked call signs display in grey, new ones in blue, and multipliers in red, based on the rules of the contest), and fine tuning ability. Using two different decoders at once also helps to figure out the message when there is noise, interference and fading as they use different decoding algorithms. N1MM supports up to 4 decoders at a time which can be used to "vote" for the right interpretation.

I'm still working on finding the best way to integrate all the software without having them fight over the control ports and audio interface. LP-Bridge is a way to have two programs share the same serial port but it's a hassle managing all the layers of software, and is reputed to have performance problems as well as some restrictive licencing.

For non-contest operation, N1MM is usable but not ideal. It doesn't like to flip modes nor can it log modes that aren't supported in the Cabrillo format (JT65 and JT9 for instance, which I frequently use). So I set out in search of a better way, which will be the subject of a future post.

The Bottom Line

I'm not a competitive contester (yet), but using N1MM has transformed the contest experience. By using a footswitch and mounting the microphone on a boom for the January 18th North American QSO Party, it left my hands free to work the radio and the keyboard.

With that in place, the logging process didn't slow down the QSO rate and the number of contacts per hour has gone up substantially. With ARRL Field Day only 5 months away, the job now is to perfect the digital operation and reach the goal of doubling last year's score.

Postscript

I should hope that every club member who uses simplex communications, whether on HF or VHF, has signed up for Logbook of the World. While signing up isn't the simplest of tasks, setup is getting easier and uploading logs is simplicity itself, especially with a good logging program LoTW accepts both ADIF and Cabrillo files, typically used for general and contest logging respectively. I have noticed that contesters are much more likely to load their QSOs into LoTW, as are digital operators. The confirmation rates have been pretty good. Excluding the contacts from the 80's that I transcribed from my paper logbook and uploaded, the percentage confirmation is 59%.

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