[Karsten]

In the attached .pdf I have described and fully documented the modifications I have made to my tester. The major one is the replacement of the Vg potentiometer by a potentiometer – digital panel meter combination which has several additional advantages. This may be of interest for those folks who struggle with a more or less defective and irreplaceable Grid voltage potentiometer.
The 90 Ohm backing off potentiometer has been replaced by a modern 100 Ohm standard conductive plastic type. Its alignment with the existing etched scale values has turned out to be easy and accurate.
Another modification is the use of the built in analogue meter for direct measurement of anode current.

- Karsten -