Down the Rabbit Hole
A couple of years ago, I found a Johnson Viking Mobile transmitter on eBay. It appeared to be complete and in pretty good condition. The price wasn’t too unreasonable, so I made a bid and won the auction. It is about the size of a shoe box. I planned to ease into tube equipment restoration by starting with a relatively simple project.
Ten Tec documentation is minimal at best and there aren’t any professionals at Ten Tec to consult any more. We’re on our own. I’m sharing a minimal alignment process I used to get a radio back within spec.
Building a solid state DC converter to power a 1950’s era mobile tube transmitter. The build uses an NOS Triad TY-83 toroidal transformer and high-power germanium transistors – the best available power conversion tech in the late 1960’s and early 1970’s.
That left how to spot weld. There are many YouTube videos showing how to do it with a commercial tool, but one vid showed a homemade welder that was little more than a motorcycle battery, push button, horn relay and some leads. I could do that.
With the Ten Tec Argonaut 509 restored and working well, it was time to try it out. The Anderson Power Pole made it easy to connect an 8 amp hour gel cell. I hooked it up to my end-fed half-wave antenna and listened around 20 meters. There were plenty of CW signals and I quickly realized a CW filter was going to be needed.
By now, I’ve written about quite a few classic Ten Tec radios. There are those who would argue that the Argonaut, first introduced in 1972, started it all though. It was the first recognizably Ten Tec product and would set the style for decades to come. It was also the first popular QRP transceiver that included both CW and SSB modes.
In late 2020, I bought a Ten Tec Omn VI+ transceiver (model 564). It was a big step for me since most Ten Tec equipment I had purchased before was older and pretty inexpensive. The Omni VI+ represented a step up both in performance and cost. Released in 1997 with an MRSP of $2850, It was Ten Tec’s flagship at the time.
In part one of this restoration, we tackled the Ten Tec Omni C’s two most glaring problems: garbled signals on receive and blowing fuses when the radio was switched to the 30-Meter band. I could now receive and transmit signals in almost all the band switch positions, albeit with varying sensitivity and power output. It had been quite a chase so far, and the remaining repairs would prove equally challenging.
I purchased a Ten Tec Omni Series C transceiver about a year ago for my collection. At the time, I was in the middle of several other projects, and didn’t get to it until just recently. I had been using an Omni D, but it still needs work and I thought the “C” would be a nice upgrade.
I finished circuit repairs on a Ten Tec Triton IV transceiver and now it was time to address the grubby cosmetics of the radio. The radio had obviously been used as a mobile. Markings had been added to the front panel in Sharpie, and there was a yellowish film on the panel.