Would someone please get me started on interval measurement with HP5370A - Page 1
Forum section: electronics / general

author: tkamiya
author_rank: Super Contributor
timestamp: February 19, 2020, 02:53:48 am
content: Hello. I'm a hopeless newbie again. (again?) Everything I did so far has been frequency based measurement. Simple, easy, and familiar. Now I have to learn interval measurement.I have a relatively new addition to my lab, HP5370A. I have to admit; however, I am very confused about time interval counting in relations to time/frequency measurement. Of course, I know about frequency and period. I know there is a START pulse, and then there is a STOP pulse. But signal that I'm going to be measuring (output of various 10MHz lab standards) is a continuous wave. There is no start, and there is no stop. It's CW, it's CONTINUOUS.Then, there is a reference input....Software I'm using is TimeLab but I also have LadyHeather. I've been playing with them in frequency mode. I had TICC running for a while but due to ChA and ChB confusion, I have not touched it for a while.Another thing I'd like to measure besides 10MHz signal is performance of buffer amplifier. I can kind of guess, take a stable signal and split it into two path. One path goes to start, another path with delay (amp or wire?) goes to stop. Then measure the time between those two events. Since the minimum resolution is 20ps, it needs to be divided down to slower signal, like 1 pps?I have to warn everyone, I'm very slow to catch on. Once I can get started by say, making a simple measurement, I can take it myself further. But I'm stuck at a very first stage. I read everything I can find in last 3 days but they only confused me more. (I'm slow to catch on...)Does anyone have patience to take me from zero to making simple measurements?(I know about input sensitivity in > 5V input)

author: tggzzz
author_rank: Super Contributor
timestamp: February 19, 2020, 09:04:02 am
content: I'm not sure what you are expecting from people, other than repeating what is in the manual.I suggest you try something very simple, e.g. measure the output of a signal generator. After that, tell usyour experimental setupwhat you expect to seewhat you do seewhat you imagine is happening

author: tkamiya
author_rank: Super Contributor
timestamp: February 19, 2020, 05:19:56 pm
content: I tried my best to describe my needs and that I am totally and thoroughly confused. RTFM is obvious. I did that. (more precisely, I tried that) I went through number of internet resources. But I have a condition that makes consuming huge amount of information and putting it into use difficult or impossible. I'm in latter case at the moment. (yes, I am medically diagnosed as such) Please do understand, I am not asking this out of laziness. Plus, none of them talks about using the counter with TimeLab. Usually, this kind of thing is a struggle, but right now, it's not even do'able.What I'm asking is, would someone be so kind to guide me through my first measurement. I have two kind in mind. 1) Adev of a signal source: 10MHz, and 2) effect of an amplifier on such signal.Maybe I'll just forget this for now and try again during the time I'm better. Thanks.

author: tggzzz
author_rank: Super Contributor
timestamp: February 19, 2020, 06:32:26 pm
content: Quote from: tkamiya on February 19, 2020, 05:19:56 pmI didn't even consider you were being lazy!Your latest questions about ADEV are rather different to your original questions.I couldn't give a better generic explanation than those you will find in manuals; sorry.

author: ZigmundRat
author_rank: Regular Contributor
timestamp: February 20, 2020, 05:41:05 am
content: I can’t write more at the moment, but you might start with the thread here: <https://www.febo.com/pipermail/time-nuts/2010-November/051860.html>Also, google search of: site:febo.com 5370b "time interval" should yield some relevant results. You’ll have to do a bit of reading, but it’s always enjoyable to read the archivesAt a basic level, it’s not too hard:“ ADEV of a standard is done by comparing two references against each other. With a 5370 typically one source starts a reading and the other source stops the reading. There are many different ways to set this up. A lot depends on the sources you have.One common way is: Set the counter to start / stop time interval mode. Let a PPS start the reading and a 10 MHz stop the reading. You will get data once a second. The time difference between start and stop will be the phase of the 10 MHz sampled once a second. “That’s the method I use most often with my 5370Bs. Start with that and see if you can start plotting some results. Then move on to the deeper questions. Hope that’s of some help.