Bit OT, made new graticule for my old analog scope

If it can't be calibrated, it's a piece of hobby level junk.

I'm still not following you. Calibration is a measurement. Then if it is out of calibration you can either adjust it or if it is cheap enough, toss it out. I don't follow why the calibration can't be measured on an inexpensive scope.

Even if it is inexpensive, it would not take much to provide a calibration adjustment to the oscillator to allow the timebase to be brought to some spec. The amplitude adjustment can all be done in software/firmware/gateware. Besides, I recall that for the analog scope (the only ones I was ever intimate with) accuracy is only 3% which seems to be on par with the TDS3000 series scopes (2%++). That shouldn't be too hard to achieve in most digital devices.

What exactly do you expect from a scope calibration? I mean, what is the cut off between "hobby level junk" and other devices?

Rick

Sigh. Uncalibrated equipment is useless for real work. Calibration standards in the US must be tracable to NIST, and the actual equipment compared to it per the OEM schedule. Apparently you've never used any real test equipment to do work that requires the test data to be logged to a set of standards.

Why would a low cost oscope be uncalibratable? You haven't explained that. I've indicated above that even on a low cost scope the two primary measurement features could easily be made adjustable.

Calibration doesn't imply any specific accuracy. It just verifies that the device still meets the spec of the unit. That is done with a measurement. If the unit is "out" of calibration it can either be adjusted to return to the spec or can be tossed as unrepairable. Over the years, a lot of equipment has gone the route of eliminating adjustments to reduce cost and having to be tossed when worn or broken.

If you don't want to talk about this, please don't reply. I'm not looking for an argument or trying to prove anyone wrong. I'm trying to understand your original statement, "the ability to meet calibration requirements keep them from being cheap."

Rick

I give up. You have no clue about how real test equipment is designed & built. 30 years ago the 'Cheap Scope' would have been called 'TV shop grade' like the old Heathkits that have hit the landfills or are sitting in someone's closet for the most part. They sort of worked, but left a lot to be desired if you had ever used a real scope with triggered & delayed sweep, multiple channels and accurate gain displayed on the CRT. Cheap scopes had poor linearity. You might as well use a Millen 1" scope: