Tom,
Thanks, the concept of de-trending is understood and the first
sub-sample is a very good estimate of the trend but its a bit
frustrating not to understand how to implement in integer math the
regression sums when the x interval of the subsamples is not constant as
the capture moment depen
Erik,
The hp 53132A counter was mentioned in an earlier posting. Check the
documentation on the frequency command(s) and also the programming
examples in the appendix. Look for words like: "pre-measurement",
"expected frequency", and "optimizing throughput". Another good source
is the SRS FS7
Magnus, Tom,
I can't thank you both enough for all the good input.
As this email contains some attachments and inline picture it goes
directly to both of you.
1: I've tested varying the slew rate. With a slow slew rate the trigger
level setting showed a much increased range for changing the p
Erik,
You also also test the issue by vary the slew-rate of the input signal.
The trigger circuit will convert voltage noise into time noise, and any
such leakage will become larger time for slower slew-rate.
You can look up Collins paper amongst others for zero-cross-detectors.
Combining th
Hi
Pretty much *any* counter can measure 1x10^-9 if you leave the gate
open long enough. Gate time matters. One can *assume* a 1 second
gate time, but that’s not always the case. ADEV suffers from this same
“unstated time” issue.
In “HP” terms 1x10^-9 at 1 second is roughly a 5335 from back in
Magnus,
Thanks, good input. To check if there is "pulling" between the two
counter inputs I used two signals generated by two PLL's from the same
OCXO. First measurement is both at 10MHz. The ratio of these two signals
was measured in the two counters using a shared 10MHz reference with a
0.1
Erik,
You should be aware that cross-talk of transitions is a factor here. It
"pulls" the transition to the time-base clock.
It can be worth evaluating this by delaying the time-base clock in
controlled manor and measure non-linearity of the time-stamps.
A similar test is done between two i
Hi
Without knowing the ultimate “target use” for this system, it is
very hard to guess what will or will not be a problem.
As an example, lets say we’re “building an engine”:
Ok, engines go into chain saws. Engines go into dump trucks.
Engines also go into airplanes. Some are run in stationary
