The Ten-Tec Model 301, now out of production (see paragraph below), is a remote VFO control for the Omni V and Omni VI/VI+ radios (there may be others, but this is all I am aware of now.). The beauty of this device is that it can be placed at a convenient location on/around the operating desk. In my situation, the 301 is located on an outboard tray on the right side of the desktop keyboard tray. Rather than reach up and across the desktop to the radio a million times during a contest, it's a simple matter to move my right hand from the keyboard to the 301 and tune. It certainly makes for more comfortable operating and tuning. That has to be worth at least 50 QSO's over the course of a contest. :-)

With the installation of the second Omni VI on the desk, I installed a toggle switch at the top of the 301 case to allow me to easily switch the controller between the two radios. This is an added convenience that has to be worth a few more QSO's in a contest. :-)

The optical encoder is the heart of the device. Shaft rotation produces on/off outputs (Quadrature, two channel) at pins A and B. The two other leads are +5 volts and ground. The cable is terminated with a male DB25 connector to mate with the DB25 panel connector on the back of the radio. The cable length is about 7 ft. Whatever's a reasonable length in your situation should work. I'm thinking about extending the cable to reach the computer desk across the room for when I am doing computer stuff but listening to the radio in the background.

Notice the black object in the lower clamshell half of the enclosure. It's a lead or steel weight. It helps to stabilize and secure the box in position when tuning. I recommend it. I also bored out holes for the enclosure feet in the keyboard shelf to further fix the box in position. I did the same for my paddles on the keyboard shelf, too. It made a big difference.

In discussions with others about the box, I have heard of or thought of installing the following functions:

  1. A=B & A/B VFO Buttons
  2. An External Keyer
  3. A RIT/VFO Switch*

(* = The Omni VI+ (and other?) radio's RIT and VFO utilize identical optical encoders)

I'm sure there are many other ideas that could be incorporated into such a box. It's simply a matter of personal choice, need and the desire to make it happen. The beauty of it all is that Ten-Tec's radio construction philosophy is such that it's easy to get into the radios and 'work' on them.

Making Your Own Remote VFO Control Box

As you can see from the picture above, the heart of the remote VFO is the optical encoder. When I bought the parts for the remote VFO from Ten-Tec, they provided an Oak Grisby encoder, model 90Q125-02-00245, as part of the 'kit.' (Oak Grigsby, 84 N. Dugan Rd., PO Box 890, Sugar Grove, IL 60554-0890. Telephone 630-556-4200. Cost: unknown).

There may be other manufacturer models (Hewlett Packard, etc.) that will work just as well.

The basic parts list:

  1. Enclosure - Sloped front works very well.
  2. Optical Encoder
  3. Tuning Knob - I bought the knob from Ten-Tec--think it was about $15.00.
  4. 4 conductor shielded cable (3+shield)
  5. 4 or 5 pin terminal strip
  6. Steel/Lead weight
  7. Cable Clamp
  8. 5-pin female molex type connector (it may come with a new encoder).
  9. Male pin DB25 connector and backshell.
  10. Rubber feet

Connecting the Encoder and Cable

Pin nomenclature as marked on the encoder:

Wiring List

DescriptionEncoderDB-25
Ground "-" 1 and 14
Phase 1 "A" 6
Phase 2 "B" 8
+5v "+" 16