[timmy]

well all i had to try was 300ma but to be so bright with the increase in voltage and the filiment still with that added voltage dont look bright at all like its getting to much voltage as it would get brighter with added voltage. those resistors, there is 2 of them ? increasing the heater voltage would have a positve affect on worn out phosphor ? is it at all possible that this sylvania crt has a defect in the heater like maybe a higher voltage filiment was put in because from several different 7jp4 tubes i looked at all had the heater housing turned black from heat and maybe lots of use yet this one has nothing on the heater housing at all that would suggest lots of use and by putting higher voltage to the heater it did not make the heater much brighter at all where as i thought it would have. the reason i ask this is because i get just bearly a shadow for a picture in a dark room as if there were no hv but adding this voltage was like having a new tube, it went from one extreme to the other.