[The last renewal of this page: July 30, 2011]

This is the first linear amplifire that I ever built when I was a college student in 1974. I was so lucky that it worked perfectly without any trouble at the first try, and was surprised its powerful job.
It worked very well without any problem for a long time, however it was regretful that I sold it to a local friend who wanted to get it so strongly about 10 years later ot its manufacture.

When it was completed, it has three bands such as 14, 21 and 28MHz, but later on, other bands were added to be the all bander from 3.5 to 28MHz.

All the parts are from U.S. military radios which were sold at Sugiwara-Shokai in Tachikawa city of Tokyo, the shop specialized to sell U.S. military junks which were brought back from the Vietnam, after the Vietnam War. The U.S. military standard was outstnading which has a big margin being left against its labeled standard.
I used a very novel and expensive mercury relay for a power relay, and the power transformers are dipped and hardened in the pitch which drops the voltage just little with a full of the load. The vacum tube was DX-362 which is the same as 4CX350 and being enclosed in a can in a military green.

Though it's pointless regretting it now, but I am so sorry to sell a thing to remember with full of such important parts that I would never be able to get again, with just a little money, hi hi.

Though this can't be an article for homebrewing as no circuit diagram is left and no pictures to show its bulding process either, here I show you some of the pictures after the completion.



When it was completed, I used to use a office locker for the power supply just like Henry linear amplifires and Collins Liniear amplifires, but before very long, I put everythings in the same type of cabinet (Ideal, UL-40) as the amplifire body to get it more compact.




The transformer is for the heaters. It runs a lot of current, so is mounted to the body cabinet.








The input circuit is a simple dummy to drive with a voltage, and needed just a little power (20-30 watts or so) to dirve the tubes fully.




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