Tektronix TDS744A calibration on the cheap

A few tips I've found while preparing for, and finally calibrating a TDS 744A oscilloscope. If you don't have time to watch, here are the main takeways:

- Supported ISA GPIB cards : https://www.eevblog.com/forum/testgea...
- CVR calibration does NOT absolutely require a metrology-grade DC calibrator
- CVR calibration needs +- 9.5V at the highest setting (not 104V as the service manual indicates) ; look at your "CVRCAL.500" file to confirm
- HF cal needs 505MHz for a 500MHz scope, at +16 to +17 dBm. Most signal generators cannot do this, but a simple RF amplifier will do the trick.
- HF cal : watch out for lossy coax cable (e.g. RG58 ) ! Even 0.6dB of loss will cause problems. Manual compensation is OK.

Segments:
00:27 3 objectives
01:51 DOS machine
03:21 CVR requirements (DC calibrator)
05:48 DIY DC calibrator
08:35 HF requirements (signal generator + amp)
10:36 first HF cal failure
13:21 second HF cal failure
16:01 interleave cal, easy
17:43 lossy coax cable !
19:10 trigger cal, easy
20:20 HF cal success !