Thank you for your suggestions.
Yes, I tried to identify the connection that is faulty. Though I mistrusted all mechanical contacts (relays and front/rear switch), my greatest fear was, that one of the PLCCs would be defective...
I opened the case and shortened all the closed contacts with an extremly low ohms short and the display changed significantly when coming to K101. Today I screwed up my courage and soldered a short wire across the contacts of this high voltage relay. It's been running for 12h now, without any wrong value.
So I've got to get one of those relays - Agilent says "orderable" at about 40 Euro. That's quite fair, I think.
Thanks so far Volker Am 21.05.2013 17:39, schrieb Don@True-Cal:
Volker, I agree with the assessment that Frank gave you, that one or several high resistance connections between the terminals you are using and the connection to the main circuit board are at fault. This path would include the front/back switch itself and any low EMF slip-on connectors between front/back terminals and switch as well as from switch to main board. 4W measurements can correct for this increasing and varying path resistance but 2W measurements can't. I have seen this behavior in the 34401A and even the 3458A as well. It's an easy fix. You can probably find the offending connection by wiggling each while watching the 2W reading with a short on the terminals. If you see the problem on both front and rear terminals, the fault is between the switch and main board. If only on front OR rear, the fault is between that set of terminals and the switch. You will want to clean ALL connectors on both Input and Sense while you are inside. Hope this helps... Don @ True-Cal -----Original Message----- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Frank Stellmach Sent: Tuesday, May 21, 2013 12:53 AM To: volt-nuts@febo.com Subject: [volt-nuts] Volt Nuts Rookie Hello Volker, welcome here. Currently, my 34401A shows a similar behaviour, on the rear connectors only. 2W Ohm there drifts up and down, several 10 digits in 6 digit mode, whereas the measurement is stable on the front connectors. 4W Ohm is stable even on rear connectors. Obviously, the front/rear switch is oxydized, or otherwise faulty. Please, check the measurement on the rear connectors also. Regards Frank _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
_______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
