In Reply to: What is wrong with the meter of my tube tester? posted by Renas on April 07, 2003 at 23:23:26:
The little screw on the face of the meter is not there for calibration, it is there to set the meter's zero position. Inside the 607 there is a way to calibrate the unit. You need to get a schematic. On the other hand, most tube testers are imprecise and relative anyway. If a known good tube scores a 65% then an unknown tube at 70% must be pretty good, eh?
Thanks for the answer. I am searching for a schematic. A seller on Ebay might have one. I asked for buying a photocopy.
The meter does not react in any leakage test with the knowed bad tubes I tried. For quality, the good are in the red and the very good can reach green. So I think it as a low voltage on the meter or a bad meter. The incapacity for leak test make it quite useless for discarding bad tubes. Guessing relative quality for every type of tube is not practical.
I will try to replace the caps unless a friend can trace the specific bad piece. I will look for a calibration device under it first.
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