" My old HP-130C scope?has two 7586 Nuvistors
in it, btw. "
A really fine rig. I read somewhere the HP-130C is regarded by some as the last good oscilloscope HP made.
By way of a little OT, mine after decades of routine use last year developed, upon warm-up, folding and contracting of the trace. The problem turned out to be transistor Q203 in the horizontal amplifier. The extend-its-life-fix was to put a 10-fins light sheet aluminum heatsink on Q203. I coated a light film of Desitin on the mating surfaces. The scope has been back to normal ever since. Desitin, which I read about somewhere on the net as a handy heatsink compound, is the baby rash creme found in supermarkets etc., it is much cheaper than the ZnO formulations marketed specifically as heatsink compound. Subjectively, I've had better luck with Desitin than the latter, perhaps because the Desitin is creamier and therefore easier to get on there as a thin film.
