"Time Interval" term used ? to cal a Pulse Generator (1973) - Page 1
Forum section: electronics / repair

author: EyeDontKnow
author_rank: Contributor
timestamp: February 09, 2025, 03:27:36 am
content: Ebay purchase:Interstate Electronics (IEC) P25 Pulse Generator(1973 vintage)Lot of two.I want to get these in running order, so I also found an orig manual.But there is a term/test mentioned for callibration....."Time interval"How I understand it.....I'm only familiar with this term when trying to "match" two frequencies, between 2 pieces of gear (meaning, 2 cables/2 signals).But there is a way to get a 'time interval from a single source/single cable. I am under the impression that this means getting a measurement of positive vs negative slope ?.... (rising vs falling ??). I am not sure.Both of my freq counters (pics) seem to have this functionality, but their manuals are not helping me.The cal manual suggests this test gear, to preform the measurement(s).... HP 5326a or 5327a Timer.Results are called-out in milliseconds (ms) or microseconds (μs).I tried using a T-adapter, splitting the single source into 2 cables plugged into my counters A and B inputs, then setting them to measure pos slope, and neg slope.But the results did not seem applicable ?

author: EyeDontKnow
author_rank: Contributor
timestamp: February 09, 2025, 03:36:38 am
content: Trying to post pics... ?

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: February 09, 2025, 04:25:29 am
content: Yes, probably the time between the positive-going signal going positive and back to negative, compared to vice versa. Here's a diagram of example good and bad cases:65 ±10 µs for each half-cycle means a frequency between 6.7 and 9.1 kHz, which seems reasonable for that range with the vernier all the way counter-clockwise.

author: benj38
author_rank: Frequent Contributor
timestamp: February 09, 2025, 01:27:19 pm
content: Indeed, as @"I wanted..." said, they want you to check the width of the positive portion of the waveform (clock high time in the diagram of @"I wanted"), and the width of the negative portion of the waveform (clock low time in the diagram).

author: EyeDontKnow
author_rank: Contributor
timestamp: February 10, 2025, 02:12:06 pm
content: Ok, thanks.What is the common method of connection to my counter ?Both counters seen in my above pics seem to have similar functions and choices:TI A/B (time interval)Slope A (rise or fall)Slope B (rise or fall)AC (yes/no)50 ohm (yes/no)....other settings on the counter to be configured ?Do I use the Tee connection like I mentioned above ? ....or ?

author: benj38
author_rank: Frequent Contributor
timestamp: February 10, 2025, 02:55:53 pm
content: Which counter exactly do you have? You mentioned what the calibration procedure recommends, but not what you have.if you have a scope, it may be an even easier option, and you will be much more confident that you are not making a mistake in your setup.

author: EyeDontKnow
author_rank: Contributor
timestamp: February 10, 2025, 06:36:00 pm
content: I have pics above, of my counters.I think I have good readings now, using the split signal method I described earlier.Here are some photos...

author: benj38
author_rank: Frequent Contributor
timestamp: February 10, 2025, 06:51:12 pm
content: Looks like you got it.

author: EyeDontKnow
author_rank: Contributor
timestamp: February 11, 2025, 06:08:05 pm
content: Last post prob.Solved, thank you.Hope it helps someone else.Here is a pic of my correct settings.These readings agree with what I see on my modern scope.(Racal-Dana 1992 counter)