Dear forum members,
I'm trying to calibrate my 2445A scope just being repaired (I've lost all the calibration settings FAIL04, had a smoking power supply. Now everything seems ok after recapping). I've got also the HP 8175A generator and Tektronix TG501 (2ns are broken) for the calibration purpose.
My plan is to go one by one CAL procedure.
Is it possible to calibrate the scope in CALxx steps after the SRAM corruption (FAIL04)?
Now I'm at CAL01, performed the 10V trimming, DAC ref calibration etc. However superimposing delayed B-sweep time markers is confusing:
- for the CAL01 step 1(see service manual) I've got to superimpose the B-sweep time markers around 6th line (center of graticule). And this is clear.
- However, for all the other calibration steps, do I also have to try superimposing the delayed B-sweep time markers around 6th line (center of graticule) within the given tolerances (1.2 division or 0.2 division)?
Also I had to repeat the procedure several time, since the time base gain wasn't correctly set (R860, R850 and R801) and time marks didn't have the same spacing as graticules.
When calibrating I keep the scope up side down (A1 board facing the top). Is it acceptable from the air flow point of view or I better to do something else?
Thank you and kindest regards,
Maxim
