Omni VI Keyer Control Mod

From the Ten-Tec Reflector January 19, 2007

Last week I asked about any thoughts on how to spread out the keyer speeds on the control of the Omni VI internal keyer. In the end I bought a 5-turn 10K pot. It arrived today.

To make the swap you first have to remove the old pot. This means disassembling the front panel to some extent. You do have to take off all the knobs (.05" hex key for the small ones) so that you can get to the secondary panel to loosen the nut holding the keyer speed pot.

The hole on the secondary panel has to be enlarged to 3/8" to accommodate the new control. Watch the shavings as you drill to keep them out of the good stuff. After removing the old pot, the new pot fits nicely. The pots I bought have three connections - #1 gets the brown wire, #2 gets the white wire, and #3 gets the purple wire. The terminals are marked on the body of the control and are not in order.

After attaching the wires, I re-assembled all that I had disassembled and was back in business.

Now a full turn of the control is roughly 15 - 28 wpm. Of course, it still goes down to 10 and up to 60 by turning all 5 times.

As it worked out, I set 20 wpm at the pointer's 12 o'clock position on one of the turns. Now each mark on the panel is 1 wpm. Sure easy to set speed.

The only downside is that the shaft of the new control is about half as big around as the 1/4" shaft of the old one. The old knob works fine, but its turns are not concentric. A shim would fix this.

I have three controls left and one is spoken for. If anyone else wants one they cost $3.95 plus postage. Or, you can buy them from Electronix Express directly, but they have a $20 minimum. If you want one of mine, just drop me an email and we can figure out the best way to send it.

73 de K1ESE

January 19, 2007

Shaft adapter for 1/4" knob on 1/8" shaft. Mouser ( 506-KR1, 57 cents in single lots. I can't machine one for that.

73, Jerry, K0CQ,

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