Fixing Stuff: A TenTec 645 CW Keyer

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.

Read more about fixing the old 645 Keyer …

A Corsair II

Figure 3A closer look at the Corsair II (left of photo).  Click to enlarge.

The first thing I did with the new-to-me Corsair II was to check the output voltage coming from the TenTec power supply that accompanied the radio.  These old power supplies can suffer from shifted component values over the decades.  It turned out that the TenTec power supply was putting out around 14.5 volts – a shade on the high side.  I took the cover off, and ran the adjustment trimmer down to a more appropriate 13.8 volts.  The previous owner had mentioned a little problem with the display not always working.  I noticed this too – but the problem seemed to go away when the voltage was reduced.

It took a little while to get used to the Corsair II’s pass-band tuning and its other various selectivity features. Once I got the hang of them, I found that …

Read more about the Corsair II …