[time-nuts] HP 54542A calibration

[BIll Ezell]

I saw in passing a question about preserving cal constants and 
calibration in general.

These scopes have NO externally-loaded cal constants, and no way I know 
of to either export or import them.
They're (almost) completely self-calibrating. The details are covered in 
the service manual.

The only thing you have to check (or can change) is the +5.2 volt supply 
accuracy. That's used to derive internal voltages for calibration.

There is one other adjustable setting, but HP says it does not need to 
be adjusted routinely and should not be changed unless you replace an 
attenuator, acquisition hybrid, or the main board. It's to set the HF 
response for the channel in question. But, it's a real pain to do 
because you have to move the power supply and you'd need to make up 
extension cables to do so.

There is a reference to 'default constants', but those are not specific 
to an individual scope, they just adjust everything to known values for 
the self-calibration.

BTW, I'm impressed with the triggering on this scope. I decided to see 
how it handles 1Ghz. Triggers perfectly. Response is 7 dbV down from 500 
Mhz but perfectly usable. Triggering was rock-stable. There are also an 
amazing number of ways to do triggering.

-- 
Bill Ezell
----------
The day Microsoft makes something that doesn't suck
will be the day they make vacuum cleaners.
Or maybe Windows 10.