[time-nuts] Difference between these two oscillator boards?

[Jason Rabel]

I was hoping someone here could tell me the difference between these two
boards (aside from their physical dimensions are different - I can see
that).

I know they are used in conjunction with the HP 10544A / 10811 boards when
inside certain equipment. Is one just a newer revision? Is one better than
the other? I can find plenty of info on the oscillators, but zilch on the
adapter boards.

http://www.rabel.org/pics/10544A/Board_1.jpg
http://www.rabel.org/pics/10544A/Board_2.jpg