First thing to look at is the accuracy.
I have standard resistors between 1Ω and 1MΩ (in decades). These are well within 0.1% tolerance (the 1kΩ was read as 999.96Ω) and plug in directly to the measurement terminals.
Using the alignment procedure I aligned it for 1kΩ (they specify 2kΩ) and then checked the same range with 100Ω and 10kΩ. Both of these are significantly out. Switching to the Rx100 range, it was pretty accurate on the 100kΩ resistor, but significantly out on the 10KΩ and 1MΩ.
It looks a bit like someone has replaced the potentiometer, and it may be a different value than the original. I think I'll order precision resistors and a replacement pot -- they won't be to expensive. I will check the switch contacts again, because these might be another source of trouble (I should do that first).
On the capacitance range it's also way out on the higher ranges. I think the replacement of the original 2uF non-polarised paper cap with a 2uF electrolytic (by some previous person) was not the best option. I had always intended replacing this anyway, so it's just one more thing to replace.
On the lower range it's also inaccurate, but in a manner similar to the resistance ranges, so I suspect the resistive division ratio needs to be fixed before I can see if there's something to fix here. I'll probably order some replacement caps anyway, as they won't be hugely expensive.
Oh, and those old terminal posts are pretty beat up and someone has hit one with a hammer (or dropped the unit) so I'll try to find some that look similar and replace them.
I did use this device to test the leakage on the two high voltage capacitors I removed. Sure enough, the large cardboard (original) one has several mA of leakage; enough to load down the test voltage considerably. The newer (Sprague) one has only hundreds of mA leakage at around 350V, so it's probably acceptable good. I used my
leakage adapter to measure the actual currents and voltages, but the magic eye is a pretty good indication.
. Both 500V 10uF.
