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A boyhood friend of mine, who I kept contact with over the years offered a dirty
dusty and gross looking tube tester to me while visiting him. At first I was
hesitant to take it.

Since I'm a junk collector at heart, I did load it into my van and hauled it

The story on how he acquired it was interesting. He has a cabin at Clear Lake,
CA and there was a neighbor that was cleaning out his cabin and dumping most of
the contents into a dumpster. On the top of the heap was this forlorn
Weston Model 788 tube tester. My friend asked the guy if he could have it, and
hauled it home.


The tube tester was very dirty and someone had painted it a dull black plus
spilled tar on the case. I removed the case and set it aside. I fired up the
tube tester and to my surprise it worked perfectly after cleaning the rotary
switches. The long original rubber line cord was in excellent condition and
quite serviceable, so I didn't replace it.


The wiring on the innards are all laced and is dressed squarely. This was
quality that I hadn't seen in years. The tester has a built in roll chart that
covers tubes up until about 1946.

The tester is a dynamic mutual conductance tester manufactured up to about 1939.
The military ordered some of these testers for the WW2 effort. There weren't
very many of these tube testers made all together.


The tester differs from the Hickok tube testers in that it don't have selector
switches to hook up the tube under test. Instead it has a patch panel like a
telephone switchboard and each tube element has to be wired according to the
base diagram of the tube. This method does make the tester universal and a tube
can be tested just with clip leads to the pins.

The guts of the tester was restored with little effort to a perfect working
condition. I have ordered a manual (rare) from someone on the internet.

I then turned my attention to re-finishing the cabinet. Much to my surprise,
the cabinet is made out of solid quarter sawn oak. I stripped the black paint,
the tar glop, and the old finish off. I then applied a red oak stain to the
bare wood, then finished it with orange shellac. The result was a dark golden
finish that made the cabinet look like a beautiful piece of furniture, complete
with distress marks.

The project is finished and I am going to put my vintage tube tester to work.