YCCC SO2R Box Product Review

This article was submitted to the NCCC Jug but didn't make the cut. Here it is for anyone who is interested:

Many of you have heard chatter about the YCCC "SO2R Box (plus)." I've been using it for over a year now and it has been a refreshing experience. This device does everything I need for essential SO2R and very little that I don't need. It comes close to what I like to call the Einstein Medium after the great physicist's admonition to "make everything as simple as possible, ... but not too simple." In fact, YCCC used a version of that quote as a chapter tag-line in the manual. The box is built like a tank and seems to be pretty bullet-proof. Unlike my two prior SO2R devices, there is no audio bleed-through between channels. It's eerie listening to two well-matched K3s alternate message transmissions on quiet bands - you can hardly tell when one stops and the other starts, thanks to the almost total absence of switching transients and bleed-through. The front panel is pure simplicity - Power switch, keyer speed knob and two Rig1-Auto-Rig2 toggle switches for Transmit and Receive rig selection. In "Auto" positions your computer controls which rig receives mic, key or FSK input and what you hear in your phones. Otherwise, you do.

The box was a YCCC club project. Paul K1XM designed the hardware and firmware. Bruce WW1M designed the PC board. Ken WO1N and Jose N4BAA handled ESD and enclosure design, respectively, and Dennis W1UE handled parts procurement and order fulfillment. They did a good job. For some photos and more information, see http://www.k1xm.org/SO2R. There was one problem with the board I received - five intended oblong holes for pins on two connectors were drilled round and too small. It took some careful drilling and filing to get things to fit but the result is secure and functional. This problem was unique to the one batch of boards that came with my kit and has been corrected. I've ordered a second box for my smaller station in Silicon Valley.

The price was right for this club project kit - about $200 for the fancy version that has four radio connectors on the rear panel. The two radio version cost even less. The front panel deals with two of the possible four radios at a time. Software controls which of the four connectors is considered Rig 1 and Rig 2. Although I haven't connected them yet, I have some VHF and bench radios that are candidates for sockets 3 and 4.

The support software consists of two simple programs that work alone or with your logger. "SO2R Box Utility" is intended for setup functions without a logging program and "SO2R Box" is for run-time control with a logger. I'm not sure about their program naming choices but the programs do the job. At present, both run as ordinary programs, not denizens of the Windows System Tray. They moved cleanly from Windows XP to Windows 7. The neat thing about the software is its simplicity. There are relatively few parameters and most of their functions are pretty clear. The run-time program has about ten pull-down value selectors, a dozen check boxes for yes/no options, and "radio buttons" to select two multi-choice options. Most of those controls just adjust keyer parameters. Compare this to microHam uRouter with its dozen tabs, each more complex than the entire YCCC run-time program or the similarly sized Utility. Piece o' cake!

Of course, the comparison with uRouter and MK2R is like apples and oranges because the YCCC box has far fewer functions than the microHam. It does nothing for rig control - you use your own serial ports or USB-to-Serial converters. It contains no sound card(s) - you use the one in your computer or external cards. It doesn't contain recording loops, ancillary volume controls, programmable configuration buttons or four layers of configuration SAVE functions. It also has far fewer setup options for tailoring it to your own favorite definition of SO2R. It just does what I consider to be the essence of SO2R: listen to the main receiver of one radio in each ear most of the time and mute (or mix) the transmit rig when the computer is sending. Unlike computer sending, paddle sending doesn't mute the transmit rig, so you can hear yourself send. And if you switch manually to one rig or the other, you get full stereo from that rig, with its main receiver in both ears or with its main receiver in one and a sub-receiver in the other. This setting also allows full QSK if the rig is set up for that. There are some alternatives to these behaviors - you can turn off the "Stereo" function to make it select one receiver at a time and you can defeat the "Latch" function to avoid muting the transmit radio during computer sending. MicroHam offers dozens of user-programmable, alternative methods of operation, setting up each ear for many possible audio sources in each of many conceivable states of operation, but after several years of noodling all that, I failed to discover any other combination that I wanted to use.

Another useful comparison is with the venerable Top Ten Devices DX Doubler. That box has controls similar to the YCCC box but with a fatal flaw - without a built-in keyer, it has no way of knowing when paddle sending is in use, so it mutes the transmit radio unless you throw a switch before sending with the paddle and then reverse it to resume SO2R audio switching. Some ops, with some logging programs, can program and remember enough function keys to accommodate most special transmissions, so they rarely have to use the paddle. But not me. I use the paddle a lot and the YCCC box aces the DXD in that respect. Perhaps in its favor, the DXD requires no support software at all; it is strictly an external switching device driven by a parallel port rig-select line. But I think the support software for the YCCC box is appropriate and well implemented. I think the bottom-line comparison of the YCCC device with my two prior boxes is a Goldilocks story: This one (DXD) is too simple. This one (MK2R) is too complex. But this one (YCCC) is just right!"

The YCCC SO2R Box (plus) sips 12VDC from a coaxial power plug and connects to your computer via a typical USB computer-to-device cable. It requires that your logging software support the published Open Two Radio Switching Protocol, another related K1XM production. Compatible loggers include WriteLog V10.73+, N1MM V9.8.4+ and Win-Test V4.4+. In order to facilitate adoption by logging program developers, in early versions of the project, Paul used a strange  mechanism for inter-process communication between the YCCC run-time program and your logger - simulated serial ports. You have to install one of several available third-party drivers to do this. Later, he adopted Named Pipes, an included feature of Windows XP and 7, for interprocess communication. It requires no additional driver support but the logging program has to support Named Pipes. Writelog does; I don't know about the others. I also had to set WriteLog | Radio | Headphones Split to take advantage of SO2R Box Stereo Mode. (One minor WriteLog annoyance - this setting is not persistent. It goes away any time you restart WriteLog or even any time you use Setup | Ports, even if you're "just looking" and don't change anything. I'm trying to get this resolved with the Writelog folks but I'm not getting very far. They say this bug is a feature!) Getting the logger and logger-control links working seemed straight-forward after the fact but in the event was the most puzzling part of the project. I hope they document it better in the future. Paul has indicated some interest in developing Application Notes for the various loggers at least.

As is often the case with ham shack integration, initialization sequencing is important. Many devices and programs insist that certain parts of their environment be ready and waiting when they start up. And few can recover on the fly from a restart or setup change of any other part. Even though the SO2R Box software is more tolerant than most, configuration changes often require restarting some or all components and starting over with the right sequence often helps. In my setup, it seems best to start rigs, switch box, control software and logging programs in that order, even though some variations will work some times. 

The kit is quite approachable by anyone with basic PC board experience. YCCC installs a few surface mount devices but everything the builder has to construct involves only through-hole components. Audio lines are isolated with transformers. The steel case is hefty and fits together nicely with the PC board and connectors. LEDs tell you which rigs are enabled for transmit and receive. Connectors are reasonably strong. You have to provide your own wire and rig-side connectors and build up cables for each radio; there are no prefabs available. YCCC supplies two or four 8-pin DIN connectors which are annoying to assemble but they do connect securely once they're done. Ring them out carefully to prove continuity and absence of shorts. I think I prefer the DINs to D-sub connectors operationally. Each connector has pins for stereo receive audio, mic audio, key out and PTT out. There is also a rear panel D-sub connector for external control and sensing of tx/rx selection and auxiliary lines for things like FSK and local devices. I'm doing fine so far on CW and SSB without it.

I have not yet set up RTTY but certainly plan to do so. YCCC requires a separate instance of MMTTY for each rig when using Win-Test or N1MM. WriteLog, however, is not yet compatible with the way the YCCC box uses MMTTY on transmit. Let's nag W5XD to support this!

YCCC is a club, not a company, so support comes from volunteers who have lives outside this project. If the right person goes on vacation, it can take a while to get an answer. But the answers do come and they respect the inquirer. They're good people who have achieved commercial quality in a club project. There is now a low-traffic email reflector where you can ask questions. See yccc_so2r@yahoogroups.com.

The original plan by YCCC was to kit up a batch or two and then let other clubs run their own projects to distribute subsequent batches. So far, they have done four rounds and are nearing ship-time for a fifth which they say will be the last. Readers who need a simple switching box capable of full, canonical SO2R without frills would be well advised to sign on. If YCCC retires from the effort, maybe your club could adopt this design for its own club project. It's a nice box.

If you are interested in getting into the next group buy, contact Dennis Egan W1UE at egan.dennis88@gmail.com.


Rick Tavan N6XI
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