Fixing Stuff: First up – 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 …

The Alda 103A

alda103a-001Figure 1:  An almost forty year old Alda 103A amateur band transceiver. Click to enlarge.

The Alda 103 has a very interesting history. It was manufactured (IIRC) in 1977 and 1978, which means it has a nice complement of the discrete bipolar transistors that are fairly common (now, almost 40 years later) – and thus replaceable. Readers of some of my other articles may have observed that I like to have the ability to fix …

Read More about the Alda …

For the curious, my Alda 103A rig is on youtube:

Youtube Alda transceiver tour

Ham Radio on a Pi2

quiskplussdrhardwareplusraspberry-1Figure 1: Quisk running on the second “homemade” tablet, which use a Pi2 SoC SBC board. (Click to enlarge).

Some of the other posts on this site refer to my “homemade” tablet, which I subsequently outfitted with components for ham radio usage.  I recently built another “homemade” tablet, this time using a Raspberry Pi2 board for the computing power.

Read More …

Note: This author is not affiliated with the Raspberry Pi/Pi2. For information about those projects visit “Raspberry Pi is a trademark of the Raspberry Pi Foundation.  Figure 1 contains elements of a desktop system and associated programs that have been released under a free software license (Copyright: LXDE team: As a derivative work, the respective part of the screenshot in Figure 2 falls under that same license. The full text of the licences may be found at  Fig1 contains another program that has been released under a free software license (Quisk). As a derivative work of that program, the respective part of the screenshot in Figure 1 falls under the same license (GNU GPL). This site/author has no affiliation with the author of the Quisk program. The code and full text license for Quisk may be found at