21fbp22 crt life

[timmy]

hi all, just a curious question about the 21fb or 21fj crts weather they are original or the replacements of the 1980s , im not sure what the other one was it starts with 19h i think. is there a way to determine the life left in these crts based upon the reading of emission given by the tester itself ? the bk440 i have would show 300 or higher on the scale where 200 is said to be weak. the mistake i made was i never did warm the tubes up as they say to do for a few minutes i just plugged it in and got the reading and i was done. it seemed at the time i was more determined to get to the chassis as long as i had a decent reading on the tester. besides the socalled life test and im not so sure this is accurate but would the emission reading mean anything as far as life goes.