Teardown : HP 3455A reference module 11177B-01723

[barnacle2k]

Small update:

got the cinch connectors and they are a perfect fit. (its available through Farnell/element14)
On to building a box  .

[TiN]

Revive-revive..

My 11177B was sleeping in the box since then, but dust was wiped off yesterday, as it will be brought up into calibration.
To make sure I'm not wasting time with this box, I hooked it to 3458A and let sit overnight in ambient temperature.



RAW DSV-data.

Some might look at the graph and say - Aha, tempco is horrible! Or, you sure it's not your 30-year old DMM drifting?

Yes, it's not the DMM, it's stable at LTZ 7V within 0.8ppm box over >6K temperature span, and code logging 11177B running ACAL DCV on every 0.5c temperature change of DMM, reducing DMMs TC to <0.3ppm.

Tempco of HP reference (it's 5.1V ovenized 5-pin hermetic TO-package chip)? Well, then why output voltage did not creep back up in last hour when I turned AC on and get ambient back to 30's ?

To Mod : Worth to move this thread to Metrology section, where it may reside better.

[Kleinstein]

The drift does not look to be thermal. So the TC seems to be good, but some drift / aging.

As the unit was off for a long time, could be humidity related or something similar.

[KK6IL]

Barnacle2k:

It's been some years now, how did your 3455 module work out?

Is it worthwhile to convert to a LTC2057?