I've spent some time getting my HP5316A and HP5334B working. (They are both 2 channel counters AKA frequency meters).
I am using my GPS 10MHz signal source as a reference.
With a bit of tweaking the HP6316A's clock can be adjusted to within a few tenths of a Hz from the GPS, but it drifts a couple of Hz with temperature variation.
The (much older) HP5316A has option 004, the ovenised oscillator. After allowing it to warm up, I am getting differences of a few parts in 10^-9 as per the HP5334B when it is set up to compare the HP5316A's clock with the GPS signal.
Of minor interest is that the 5316A starts up with a significantly poor clock (several kHz off), but as the oven heats up it first overshoots 10MHz, then "rings" a few times before settling on so close to 10MHz that it's hardly worth worrying about.
The 5334B, on the other hand, starts up much closer to 10MHz (a couple of hundred Hz off), settles reasonably nicely, but still drifts with ambient temperature.
One thing I haven't done (that I should do) is look at the GPS clock vs the frequency counters' clocks and watch the drift
I am using my GPS 10MHz signal source as a reference.
With a bit of tweaking the HP6316A's clock can be adjusted to within a few tenths of a Hz from the GPS, but it drifts a couple of Hz with temperature variation.
The (much older) HP5316A has option 004, the ovenised oscillator. After allowing it to warm up, I am getting differences of a few parts in 10^-9 as per the HP5334B when it is set up to compare the HP5316A's clock with the GPS signal.
Of minor interest is that the 5316A starts up with a significantly poor clock (several kHz off), but as the oven heats up it first overshoots 10MHz, then "rings" a few times before settling on so close to 10MHz that it's hardly worth worrying about.
The 5334B, on the other hand, starts up much closer to 10MHz (a couple of hundred Hz off), settles reasonably nicely, but still drifts with ambient temperature.
One thing I haven't done (that I should do) is look at the GPS clock vs the frequency counters' clocks and watch the drift