Arrived today. More coming soon ...
And, as promised, here is the teardown of this nice device: a Keithley 616 which I got for 85 Euro including shipping.
(
teardown of another 616 here in the EEVBlog forum)
The package was very well, the meter itself has been covered in an old duvet (blerk!) but it did a good job.
Sorry, no pictures because I've thrown it immediately in the bin.
Here are some pictures from the outside. Please note the rusty screw. It is untouched which means, nobody was inside before.
The Triax connector is looking good imo. Now I need a cable with a proper connector for it.
Backside, very nice binding posts.
Here are the overviews from top and bottom. I hope I never have to unsolder these screws.
PSU area, transformer, +5V, HV area and nice looking electrolytic caps. Will test them anyway and check all the voltages.
The display, front and back. These LED seven segment displays are from Monsanto but I don't know what type (2x 5 dots per segment). Those golden pins are everywhere. Aren't they gorgeous?
Some switches. Mains power switch, fast-normal switch, reed relay switch for the auto zero, rotary switch for the sensitivity, unshielded part of the ranging rotary switch
The analogue ranging board with the red Caddock resistor network and the digital board which controls the meter (including display). I didn't dare to pull them, maybe next time. Will add then the pictures here.
Let's see what's under the shielding. I didn't touch anything inside here, because this will destroy all the high impedance here.
One need to wear gloves if, for example, the pre-amp needs to be pulled.
Input termination and PTFE standoff, pre-amplifier, the high impedance part of the rotary range selector switch, some resistors and capacitors mounted on the rotary switch. There are some glass insulated resistors on it, need to take some pictures next time.
I'm very happy with this unit so far. It looks very clean and untouched in the inside.
Next step is getting a proper cable so I can do some testing. And I need to check the voltage rails and the electrolytic capacitors.
I'm looking forward to measuring the leakage currents of a few wet-slug tantalum capacitors with it.
Hope, you've enjoyed this little teardown.