Here are some pictures from my most recent acquisition -- a Philips PM6654C. Sadly, the previous owner seems to have been a life-long smoker. And as such, he left this very nice piece of lab equipment covered with a thick coating of yellow-tar-gunk. In the process of alcohol washing the entire thing, I thought I'd take a few pictures and share them with you all.
In a related thought, why did they allow smoking in the MCC...
... yeah, thumbs up to lung cancer, buddy.
Anyway, this is the base model PM6654C. It doesn't come with any of the exotic time-base options, just a single bare quartz crystal can folded right over onto to the FR4... doesn't inspire a lot of confidence in a device that can display 9 1/2 digits and claims to have a resolution of 2ns.
No worries though... my lab has a Rubidium standard that pipes a solid 10MHz right into the back of this device. Seriously though, I'd just as well put a piece of duct tape over about half of those digits if I had to rely on the non-compensated crystal. That being said, the ol' counter did alright for itself right out of the box: Reporting 1.000000185e3 on a 1kHz (0.1ppm) signal divided down off of the Rubidium clock and 1.000000656e6 on a 1MHz signal -( 0.6ppm)