[Milsurplus] How Much Vacuum in "Vacuum Tubes?"

[Todd, KA1KAQ]

I read a number of articles in old (early 20s and before) radio
magazines about amateurs making their own tubes. I have a tube in my
pile of stuff that looks very crude and crooked inside, not sure if it
could qualify as 'homemade', though.

Maybe it gets down to losing skills due to progress and cost? If you
can buy a new one cheaper, why go through the hassle and all that.

~ Todd,  KA1KAQ

On 3/28/07, J Forster <jfor at quik.com> wrote:
>  I can remember the old ads in Popular Electronics, Mechanix
> illustrated,
>  etc. where you could go into business rebuilding old TV CRTs.  Probably
> a
>  scam, I never knew anyone who responded to the ad and see what you
> would
>  get.
>
>  73, Jim, wd4air
>
>
> Actually, rebuilding a picture tube would be easier than a receiving
> tube, IMO. I think you basically cut off the neck and installed a new
> gun and evacuated and sealed the tube. Most of the envelope and screen,
> the big and expensive parts, could be reused pretty easily. B&W picture
> tubes with magnetic deflection all have pretty simple guns