how long does a tv tube hold it's charge?

The easy answer is no, there is not. When I was 'in the trade' we used to assume that the voltage was there unless we had discharged it to earth. If you are not trained to do this DO NOT TOUCH IT! BTW, even a discharged CRT can pick up a residual charge if left long enough.

Not sure why you are poking around there anyway. The only time I used to go near the CRT (or its HT connector) was to change it - which s NOT a DIY job.

t
June 2007