Figure 1: The ball bearing assembly, extracted from the old keyer
The old TenTec Ultramatic Keyer is still used today by many amateurs, including myself. Its Ultramatic keyer mode was born in 1953, and later overtaken by the Iambic A and B modes. I still use the two of these keyers that I own, but one recently needed a repair … In the video shown in figure 2, you can watch a 35 second walk-thru of the disassembly and repair.
WB8LZR 
Hi Ron,
My question for you is, how does the Ten-Tec 645 keyer operate? Is is iambic, ultimatic, or some other non-iambic mode? Also, are there mode switches on the back panel?
Thanks Ron
Brian Kelley – NM7T
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Hi Brian, Well I think it supports only the ultimatic mode, but in practice I don’t notice much difference when using my other (iambic mode) keyer. The back panel has fixed vs auto weighting, and a weighting pot. Also, there’s a dit memory (on/off), and a dah memory (on/off). Hope that helps,
– Ron
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IIRC There are two iambic modes. I think one of them (the one that is mostly used today) is really the same as ultramatic. May have to go back and check on this myself 🙂
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