[Milsurplus] I-77 tube tester question?

[Bob Camp]

Hi

There is a tech manual somewhere that goes through a detailed check  
out procedure on the beast. I have not seen the one on the I-77 but I  
have seen one on a TV-7. Given how the parts are packed into the  
beast, it's not something you want to dive right into.

Simple approach - take a couple of pentodes, slightly aged is better  
than new, and test them. Record the readings. Store them away as  
"reference samples".

There's not a lot inside a tube tester. Once you get past the power  
transformer, switches, and sockets. Generally you have a bunch of  
resistors and a diode or two. About all that goes slightly wrong is  
that the resistors drift. The other stuff like a diode failing, a  
switch opening up, or the transformer failing are pretty obvious.

Bob

On Aug 29, 2007, at 9:40 PM, john p hutchins wrote:

> Oh - Noble group
>
> I ask - When does one know when your die-hard I-77 tube tester may  
> be in need of a tune up?  Is there a "check-up" procedure?
>
> Thanks
> Hutch
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