[volt-nuts] Volt Nuts Rookie

Don@True-Cal truecalservices at gmail.com
Tue May 21 11:39:08 EDT 2013


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-bounces at febo.com [mailto:volt-nuts-bounces at febo.com] On
Behalf Of Frank Stellmach
Sent: Tuesday, May 21, 2013 12:53 AM
To: volt-nuts at 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 at febo.com To unsubscribe, go to
and follow the instructions there.

More information about the volt-nuts mailing list