hi all, I have a Heathkit IT-11 i'am restoring. i'am at the point where I need to calibrate the leakage pots. the elecroylytic pot adjust fine for 2ma. the mini electroylytic and the non-electro pots can not be adjusted. the mini electro needs to be adjusted to 15ua and non-electro to 2ua, however, rotating the respective pots, fails to close the eye tube? need some help.