Part 4: Two Radios, Lots of Antennas, How Hard Can it Be?

by Dan Levin, K6IF

This chapter is all about the SO2R station configuration for my VC1R effort at VE1JF. If you already know all about SO2R, or don’t care about SO2R, I’d skip this part – you are going to be bored.

When I first spoke with Jim about his station, he told me that he had it configured for M/2 operation. All the parts and pieces were there for SO2R – but that station hadn’t been actually used for SO2R in quite some time. If I wanted to operate SO2R, which I did, I was going to have to figure out and work with Jim to implement, a good SO2R set-up.

Now, when you talk about SO2R for phone contesting, you are really talking about a collection of loosely related topics:

1) Microphone issues. What are you using for a voice keyer? One mic or two? If one, how does the mic get steered to the ‘active’ radio?

2) Audio issues. One radio in each ear, or both radios in both ears, or one radio in both ears? How do you split the audio, and how do you control it?

3) PTT control. Foot switch vs. VOX? If you are using one how does the foot switch get steered to the active radio?

4) Amplifier, bandpass filter and antenna switching. Do we have 2 amps, or one? When we change bands, how do the filters, amps and antennae get switched?

At my home station, I use WriteLog as my logging software, and the W5XD WriteLog keyer as my SO2R controller. I use the computer as my voice keyer. The end result is a highly automated system, and one that I am very comfortable with.

Jim has an Array Solutions SO2R Master SO2R controller, but has never set it up. So my first step was to research that box, and decide if I would be happy using it. After reading all about it, I decided that I would really prefer not to use the SO2R Master, for two reasons.

1) Control of the audio output. Here there are several schools of thought. Some people like to listen to both radios all the time, some like to 'latch', which is to listen to the 'run' radio with both ears unless it is transmitting, and when it is transmitting to listen to the 'S&P' radio with both ears. WriteLog provides this control in software, and outputs signals that allow the 'official WL keyer' to steer the audio. You can run in any of three modes: both ears to the active radio, one radio in each ear, or 'latch' - and can switch modes via the software. The SO2R Master does not support this WL function, as best I can tell. Instead, the SO2R Master provides similar abilities, but controlled by its hardware control box. This is a bit more clunky, because if you want to run 'latch' (which I do most of the time) when you switch from running on radio L to running on radio R you have to flip a switch to fix the headphones (the A, A+B, B switch in the middle of the control head). WL does the switch automatically. Executive Summary, the SO2R Master would work, but would require a manual step that isn't required when using the 'official Writelog keyer'.

2) Mic switching and voice keying. Here things get more complex. The SO2R Master is designed to accept a mono microphone input - either directly from a headset (Heil, e.g.) or from a voice keyer. It will then steer that input to the 'correct' radio. This is fine, if you plan to use an outboard voice keyer of some sort. At my home station, I use WriteLog's built in voice keyer, which in turn uses the computer's sound card. The computer does the 'switching' for you, and outputs one radio on the left channel of the stereo audio output and the other radio on the right channel. I am used to the Writelog built in voice keyer using the computer sound card - but I didn’t think I minded if we used an external voice keyer at VE1JF – with one cavaet. I do care about two specific features – and I wanted whatever solution we used to provide them if possible. The first is auto-repeat. Writelog provides an auto repeat function that keeps transmitting your CQ message until you stop it. The second is auto-restart. When operating SO2R, WL allows the operator to stop a CQ by sending a message on the ‘S&P’ radio – and then WL will automatically restart the CQ as soon as the message is done. This automates the otherwise tedious process of hitting <esc> to stop the CQ, then calling the station on the second radio, then hitting a function key to restart the CQ and protect your run frequency while copying the other guy’s exchange, then stopping the CQ to send your exchange, then restarting the CQ. It turned out that the SO2R Master doesn’t support this functionality with WriteLog.

So at the end of the day, I decided that I would really prefer to use the W5XD WriteLog keyer as my SO2R controller for this effort. I decided that I would put together a complete SSB SO2R setup for VE1JF, and leave it with Jim as a gift in appreciation for hosting me.

Assembling such a set-up, especially for radios that you don’t own, is a bit of a challenge. I ordered the keyer, and while it was in the mail I built the splitter box that you need to separate the two mic outputs that WL puts on the single stereo sound card output. I also bought the nine cables we would need. Then I took the whole mess up to the Stanford ARC – W6YX, where I am a member. W6YX uses the same two radio’s that Jim has – an FT-1000MP and a Mark V. I was able to test the mic levels and my splitter box using ‘YX’s rigs. Then I labeled all the cables at each end, and wrote a 20+ step installation and testing process for Jim to follow. Each cable was labeled with the number of the step in which it was used. Then I packed up the whole kit and shipped it up to Nova Scotia about two weeks before the contest.

While the package was in transit, Jim and I exchanged digital photographs of our operating positions, and agreed on a physical arrangement of the operating desk. As you can see in the picture of my home station on the right, I prefer the radios on either side of a single monitor, with the amps and antenna switching and rotor controls on a shelf above the radios. Jim agreed to build such a shelf, and re-arrange his entire operating position to suit my preferences.

Luckily for me, Jim turns out to be a very capable guy. He was able to follow my instructions, and installed the complex and unfamiliar SO2R control setup in less than a day. Everything worked as designed, incredibly enough.