HP 410C refurbished

[bandersen]

I picked this 410C up last year. It's missing the AC probe and the DC wasn't working. Ohms is fine though.




It's very, very well made. Gold plating, orange drops, etc.


Cool neon optical choppers glowing.


This 89M Victoreen glass encapsulated resistor has broken. Seems to be OK though. I suspect a replacement will be difficult to find.


Thanks to this advice from Findm-Keepm, I quickly discovered the DC test lead had broken!

Originally Posted by Findm-Keepm

The 410C manual is everywhere - and free - Agilent and BAMA both have them.

As for the DC, always ensure your probe has the requisite 1 Meg resistor in it. It's R1 in the manual. The ohms lead is a straight lead.

If the AC probe is missing, a 22 meg resistor, 2 caps (2600pf and 250 pf), and a couple 1N4937's in series (for increased PIV) and you're back in business. Lemme know if you need a 22 Meg resistor - I've got a few Carbon Comp ones, although a 1% 1/2W film type would be best. I built one to try out the concept, but we never used it, as I potted everything and threw off the frequency response at low voltages. Don't pot it and you're okay....

Cheers,

I fixed it and it's work great now. Here I'm measuring 4.5 volts. It's dead on


I'll try to scrounge up some parts and make an AC probe as suggested.