This is the famous and somewhat rare 100 watt input / 50 watt output linear amplifier that matches the 509 Argonaut HF transceiver, but can can be used to boost the power of most QRP rigs.There\'s not much documentation for this that I can find, but I am including a multi-page description of the operation and schematics for the amp that I found on a collectors web site. Some key notes are that it requires at least 1 watt of drive (perfect for the 509), and operates through the 80,40, 20, 15, and 10 meter bands. I understand there are mods available to get into one or more of the WARC bands, but this unit is original and un-modded.
General condition is good. The front and rear are basically unblemished, however there are scratches on the top of the faceplate and back a couple of inches along the top (see photos). There are 4 holes in each side and I have no idea why they are there. It could be that a previous owner had the amp attached to a rack or panel of some sort. There are no signs of any mods as a result of these holes and if need be the sides can probably be recovered with wood-grain shelf paper.
I\'ve hooked it up to my 509 recently and although I don\'t have an external wattmeter it appears to work fine. I ran it from a 20 amp power supply but the documentation I have states that, \"The Model 405 is designed for a nominal 12 VDC power source. It will operate satisfactorily from a 12 volt automobile battery or AC power supply such as the TEN-TEC Model 250. The supply should be well filtered and regulated to 15% with an 8 ampere load. Maximum voltage should be kept under 16 VDC...\"
Although not extremely hard to find, I looked for this for about a year when I bought it several years ago. Most owners seem to regret selling theirs and if for no other reason than nostalgia for a classic Ten-Tec piece of equipment tend to start looking for another one. I have modernized all my gear and don\'t think I\'ll be in the market again, but you never know. Since I\'m selling all my Ten-Tec gear there\'s no reason to keep this piece all by itself.
I am selling my 509 in a separate sale and will soon be listing a Ten-Tec Model 200 VFO and a KR-20 keyer (once I verify its working condition).
