Anyone have experience repairing an HP3325B synthesized generator?

Looks like the data entry values as the manual refers to storing and recalling information.

HI everyone, wow what a great response thank you.

So does this look like it's 'user's setup' data that's stored and can be recalled to continue a particular test regime, as opposed to "factory" calibration that would be a disaster if lost?

beacon-dave where did you find this? is it in the service or operators manual?
I need to see a description of just what sort of data HP are calling  "Stored data".

Great stuff, thanks everyone

Dave

davebullockmbe said:

beacon-dave where did you find this?

That was from the Operating Manual dated 1997.

Perhaps check the service manual for the model A to verify that there is no battery backup to the SRAM there.

• The NV RAM is listed as one of the model B enhancements over the previous model A.
• If you switch the model B into model A 'compatibility mode' then you would appear to lose the NV backup functionality of the SRAM during standby/power cycle.
• If the model A doesn't have a battery, then if any factory calibration data was being stored there, then presumably the model A would have lost it immediately after it was powered off at the factory.

davebullockmbe said:

as opposed to "factory" calibration that would be a disaster if lost

After ≈25 years, then it may be out of factory calibration by now anyway. 

Note that there is also an Installation Manual for the HP3325B which gives you the factory inspection check list but at a glance I didn't see any reference to the NV RAM or store / recall functionality.

Thanks, yes it's always frustrating when the specific information you need is either glossed over of missing from a manual.

It's the well known Car maintenance manual problem isn't it?

eg. "To remove the water pump first locate the 'throggle pin' and with the special spanner loosen the 'cratchitt collar and withdraw the pin". No indication of where either mystery part is,  or what the special spanner looks like in the subsequent text or diagrams...lol! 

I am thinking that it's looking like the SRAM is just storing operational data rather than vital calibration data then.
Yes these signal generators were pulled from 19" racks in an audiology laboratory and look like new, amazingly.
I haven't found any real issues with the calibration but I now only use them in less exacting situations.

The fault I was initially repairing I traced to 'granulated' solder joints where there was a ring of grey cracking around the soldered pins on the three flat ribbon cable connectors half way down A26 leading through the 'deck' to the lower section. I wasn't expecting such a 'dry joint' issue with gold plated HP boards so lesson learned!

Dave

davebullockmbe said:

it's always frustrating when the specific information you need is either glossed over of missing from a manual

Perhaps be thankful that there were at least three such manuals available. These days you are lucky if you get a generic 'pamphlet' that even remotely matches the operation of your equipment.

davebullockmbe said:

or what the special spanner looks like

Or that with the engine/body in place, even with the 'special spanner', it is less than an eighth of a turn between engine block and bulkhead and it is the world's longest bolt that is 'tight all the way'... 

Lol...been there ... got the missing knuckles :-)

Lol...been there ... got the missing knuckles :-)

Me too - spanner slipped while tightening cylinder-to-crankcase nuts on the Aerial VB 50 years ago! Shouldn't have used a slippery spanner...