Calibration guide for a "RACAL-DANA 9906 Universal Counter Timer"

[wobbly]

Hi,

Just today I finished refurbishing a lovely 1984 vintage RACAL-DANA 9906 Universal Timer Counter unit.
It works just fine and dandy but it does require calibrating / tuning.  Last time it was calibrated was early 2013 according to the stickers it came festooned with.

When reading a 1 MHz sine wave signal from my sig-gen (a calibrated Keysight EDUX1052G Wave Gen output) it measures 999,995 Hz, or in other words 5ppm low.
Similarly, at 20 MHz (the Keysight's maximum output freq) it reads 19,999,900 Hz, again 5ppm low.

The user manual is readily available for this machine, but this document does not cover the calibration / tuning procedure.  For the life of me I cannot find the "service manual" or "calibration manual" for this device.

Can anyone point me in the right direction so that I might get my 9906 properly dialled-in and reading true?   

[coromonadalix]

http://ftb.ko4bb.com/getsimple/index.php?id=download&file=Racal/Racal_Dana_9901_Universal_Counter-Timer_Service_Manual.pdf

Does it show some similarities with this one ??      There was some similarities between some models in this era ??

[wobbly]

I think this will do the job!  At least for now anyway.

I've currently got my scope (triggering from it's integrated wavegen set to 1 MHz, 4 vp-p) sampling from the 9906's output BNC.

The calibration trimmer is (amazingly) still working smoothly after all these years.  I'm still waiting for it to warm up to a stable temperature, but I've already improved the accuracy of the unit .  Another hour or two and I think I'm in business!

Thanks for finding this, good on yer