[R-390] Tube esters - TV-2

[Kenneth G. Gordon]

On 25 Jun 2007 at 19:36, Scott Bauer wrote:

>  From a maintenance point of view, I was told by Bill Waters " The
> Hickok Doc" that he won't even work on a TV-2. I do not know why. I'm
> just quoting him.

I can think of several reasons: 

1) the early models had quite annoying problems with parasitic 
oscillations. In my case, those tend to kill A) the 83 rectifier, then B) 
the 6X4s, and C) any VR tubes you attempt to test. Later models 
had oodles of ferrite beads hung on practically every lead in them 
in an attempt to cure this problem. Furthermore, you can't really 
retrofit the ferrite beads since there are so darned many wires in 
there it would be easy to lose track.

2) The power transformers tend to get intermittant shorts and/or 
opens in them. Replacing the power transformer is NOT for the 
faint of heart.

3) They are AWFULLY darned big!

I have two TV-2s, an early and a later. The early one has destroyed 
at least two sets of rectifier tubes, and I won't use it to test VR 
tubes any more. I watch it like a hawk when I do use it.

The later one has a transformer fault and, so far, I have not had the 
courage to attempt to fix the thing.

I was asked once to trade an R-390 for one of my TV-2s, but since 
I could never get the later model one to work, I just gave up on the 
trade.

YMMV

Ken Gordon W7EKB