How to FT8 on a Ten Tec Omni VI+ with a Mac
Using FT8 on an Omni VI Plus with a Mac
Two Methods:
After getting the serial port sorted out on the Omni VI Plus (Omni VI), it was time to get FT8 running. I’ve covered running FT8 with a Mac in a previous post, so I would recommend reading that first. In this post, I describe two methods. One uses a Tigertronics SignaLink USB sound card with a FTDI-based USB to serial adapter. The other is based on a MicroHam MicroKeyer and a Sabrent USB audio adapter. Both methods satisfy the FT8 (and other digital modes) need for Computer-Aided Transceiver (CAT) control and a sound card for getting audio to and from the transceiver.
BlueMax49er FTDI and Tigertronix audio card
The SignaLink USB approach is conceptually the simplest, but requires investment in a SignaLink device. While occasionally available on eBay, they almost always go for around $100, and a used one might not have the jumper board or custom cable you need for your radio. It’s probably best to just buy a new SignaLink bundle (which includes cable and jumper board) for around $170.
CAT and audio connections
To connect with the Omni VI, you’ll need a CAT connection to the DB-25 serial port on the radio. This allows MacLogger DX (or any other CAT aware software) to directly control the radio. BlueMax49er makes a custom FTDI-based adapter that is guaranteed to work with the Omni VI.
MLDX Configuration
The setup is nearly the same as described in my earlier post. In other words, if you have MacLogger DX (MLDX) connected to your radio via a USB to serial cable (the CAT connection) and it is working properly, use the instructions from my earlier post to download WSJT-X and configure it for FT8.
Easy and works well.
The combination of MLDX, SignaLink USB and Omni VI works well for FT8. Audio levels to and from the radio are set using the controls on the front of the SignaLink USB and the Mic and Power Level controls on the front of the Omni. I found that setting the “Mic” level to 11 O’clock and the “PWR” Level to 1 O’clock resulted in about 25 watts output — perfectly adequate for making FT8 contacts easily. By the way, the transmit audio levels (“TX” on the SignaLink and “Mic” on the Omni) should be adjusted so that the ALC light just turns on. Some ALC action is desirable for FT8.
MicroHam and Sabrent USB Audio
About the same time, I noticed an original MicroHam MicroKeyer — complete with a cable set — on eBay for a bargain price. Since MLDX also supports the MicroHam keyer software, I thought this might be interesting.
The original MicroKeyer (about 20 years old as I write this) consolidates most of the computer/radio interface for CAT, RTTY, Packet and other digital modes with a single USB connection to an external box. It also includes a contest CW keyer and galvonicly-isolated audio interface. The box, in turn, connects to the radio through a custom pigtail with various connections like Mic, Key, PTT, Audio In and Out, and Serial Data. In theory, this will clean up the cable installation while minimizing digital computer noise in the receiver.
All this was new to me, but the challenge of this level of computer/radio integration was intriguing. I also aspire to better CW, and I knew the MicroKeyer was intended for contest use. The only fly in the ointment was the cable set included with the eBay listing was for a Yaesu radio. Well, the price was right and I’ve spent a good portion of my ham career making cables anyway, right?
Rewiring the MicroKeyer pigtail
I’ll spare you the gruesome details of re-wiring the DB-37 connector and pigtail — about 4 hours of work. The good news is that MicroHam publishes schematic diagrams of every pigtail they sell to fit specific radios.
This is great since all I had to do was compare the diagrams for the original Yaesu pigtail, compare it with the schematic for the Omni VI pigtail, and change anything that didn’t match. I also needed a way to get audio in and out of the computer. The M1 Mac Mini has a single 1/8th-inch mini connector for a headphone connection. They expect the end user to add some sort of audio interface. Likewise, the original MicroKeyer does not act as a sound card. Modern tech helped here though.
Audio connections
The Sabrent USB audio interface is a brilliant, tiny, inexpensive way to make audio connections. Since the MicroKeyer has audio isolation transformers and level controls, the Sabrent is a practical way to update the original MicroKeyer while preserving its benefits. All I had to do was run audio cables between the MicroKeyer audio ports and the Sabrent. Of course, the Sabrent, which appears as “USB Audio Device” to the computer, will have to be selected in the Preferences ->Audio tab of WSJT-X. Incidentally, the current MicroHam model — the MicroKeyer III — adds many features including a built-in 24-bit sound card.
The software configuration was tricky
With all the hardware connections made, it was time to tackle software. The process is actually much easier than I initially thought. As I was configuring the hardware settings for the Omni VI CAT control (MLDX -> preferences -> radio) , I saw something called a “Micro Router.” I couldn’t find any mention of “Micro Router” in the MLDX documentation.
The PC and Mac worlds are different
Here’s what I ultimately learned. Most hams use the MicroHam hardware with a PC. The PC version uses a helper app called “Micro Router.” There is a Mac version of this app, also called Micro Router. It’s a bare bones version though, missing many of the PC features. This old Mac version was last refreshed many years ago, and although it will launch on a modern Mac, it doesn’t find the external MicroKeyer hardware. At this point, I was beginning to think I was dead in the water.
MacLogger DX to the rescue!
It pays to read the ReadMe files. Included with the MacLogger DX installer is a folder labeled “Extras,” and within that, another folder labeled “Apps.” One simply copies the app “µH Router” to the Applications folder. A check of the “Get Info” page for the µH Router shows it was recently updated by Don Agro — MLDX’s developer, and it’s the missing link between the MicroHam hardware and MLDX. µH Router is a stand alone app, and can also be used to configure a few settings within the MicroKeyer.
For most Macs, launching MacLogger DX will also launch µH Router. All that remains is making an MLDX and WSJT-X configuration for the Omni VI Plus. As mentioned in my post about adding CAT control to the Omni VI, the radio setting that actually works for the Omni VI is “Icom IC-751,” with a device ID of 4, at a 19,200 baud rate. The ID and baud rate can be changed on the Omni VI using the settings described in Table 3-1 of the Operator’s Manual. MicroKeyer connections are added to MLDX using the “PTT” and “CW” drop down menus on the MLDX -> Preferences -> Radio page. The final configurations for MLDX and WSJT-X are shown below.
That’s it. I find it’s best to power the Omni VI, then launch µH Router and finally launch MLDX. If MLDX produces an error message or quits unexpectedly, Shut both MLDX and µH Router down. Cycle the power on the Omni VI and relaunch the software. The software isn’t bulletproof, but runs well. Your mileage may vary.
So, is it worth it?
The Omni VI Plus is a great rig for FT8. Although it’s hard to prove, I have the feeling that the Omni VI produces a slightly higher percentage of completed contacts than the Elecraft K3 in the earlier post — although this may just be my imagination. In any case, I’m happy with either one.
The MLDX/Omni VI/MicroKeyer combination is really interesting. It’s just as solid a performer for FT8, and adds CW contest capabilities to the Omni VI that I’m still exploring. Although not documented very well, MacLogger DX has a surprising number of really useful features. In this respect, it’s very Mac-like; lots of functionality, but you’ll have to discover it yourself. This is not a complaint though. I would much rather the developer continue to add functionality and improve stability. It’s the small developer’s paradox, but I salute what’s been incorporated so far. And, I’ll continue to hunt for those Easter Eggs! By the way, adding a rare contact or two doesn’t hurt either.
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