Hi Philip,

Great find. The 5372A beast (and it's siblings) can be quite daunting to
start using for a user, as it has quite a bit of a different user
interface and configuration range. I think I have the physical manual at
hand, but it is great that people can find it online. These boxes can do
some really great measurements if used wisely.

For those wanting to dwelve into how counters really work, I suggest
going into the rabbit hole of the 5372A programming manual, with the
other manuals at hand. It's very transparent, but on the other hand, it
can do so much it becomes daunting to track all the different trigger
modes, but it is worth the effort to understand different measurements
if you want to dig deep and learn calculations etc.

Cheers,
Magnus

On 2025-02-12 02:26, Philip Freidin via time-nuts wrote:

I have the operating manual, service manual, programming manual, short
guide, if needed, ask.

And an HP5372A still working after a power supply, FAN and Probe Modules
repairs a few years ago. (Diode ST3020 C, CR1, replaced by a 25A bridge.

The probes modules have a strong tendency to have broken solders inside,
the solders that assemble both PCB. Causing sporadic calibration errors
and / or not working inputs.

I had two modules with this problem. Quite easy to repair.

Another frequent problem is the internal lithium battery, to be replaced
every few years. Input Calibration necessary after replacement.

Olivier ADLER

Le 12/02/2025 à 02:26, Philip Freidin via time-nuts a écrit :

Hi,

For many uses, the HP5371A, just as the 5372A, is a really good counter.
Use it as long as it is meaningful to keep it repaired and operational.

The 53230A is a better counter, but not all measurements will be
significantly be limited by the choice of counter, so there having the
additional counter makes good sense.

A similar argument applies to say oscilloscopes. I bought a pair of
Tektronix TSD 220 scopes in 1997. They are far below preformance wise
both the TDS 640 and many other scopes we got since. The TDS220 scope
remains popular for the "quick check of signals" and one has a failed
Channel A and it is still in use.

However, the 5371A/5372A may be a bit hard to use. However, a good trick
is to set them up for frequency measurement and make them make measure
multiple points. As you look at the statistics view, you get a linear
regression estimation and this still enables it to do really well! To my
knowledge, it was the first onces to include that processing, back in
1988. If someone knows counters prior to that, I'd love to hear about it.

Cheers,
Magnus

On 2025-02-14 00:44, Jim Muehlberg via time-nuts wrote:

Olivier ADLER via time-nuts writes:

The differences between 5371, 5372 and 5373 are so slight that manuals
for all three are relevant and useful documentation.

Here is all the information I collected when I still had my 5372A:

https://phk.freebsd.dk/misc/HP5372A_doc.zip

--
Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG        | TCP/IP since RFC 956
FreeBSD committer      | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

Hi,

On 2025-02-17 08:56, Poul-Henning Kamp via time-nuts wrote:

A word of warning, for many operational things, they are quite similar,
but the Programmers manual for 5371A and 5372A is as I recall covering
some quite dramatic changes. Some of the boards in the 5372A is the same
as in 5371A, but the 5372A adds hardware histogram processing and also
have some other modes changed. So if programming those things, check the
right manual. For most measurements we typically do, the 5371A is as
good as the 5372A.

I have not dug into the actual difference up to the 5373A, and I have
not encountered one either.

Cheers,
Magnus