Sencore CR70

[tvcollector]

I'm noticing with my Sencore CR70, When I was testing a color roundie tube that after a few times shutting off and setting and turning back on to test each gun, I'm not able to get the filament voltage to 6.3, it goes to about 5.5 with the variable setting all the way up... Seems like after it's been on for a while the big load of the tube puts a toll on the tester.. Even switch to 8 volts it's goes up a bit into the 6volt range... If I take take the tube off the tester I'm able to get the range.. I'm guessing there are some bad caps or maybe some resistors in the Sencore.. I don't have a schematic for this thing If I were to look into it...

I'm able to test the the tube at 5.5 volts but it not going up to 6.3 volts.. I sure I'm not getting the full results..