[time-nuts] Frequency Counter Choice

[Magnus Danielson]

Hi,

On 2020-10-22 19:13, Attila Kinali wrote:
> On Thu, 22 Oct 2020 11:50:08 +0000
> Giorgio Barinetti <giorgio at barinetti.it> wrote:
>
>> Choices are many, but I'll try to avoid the "older" machines lile 5370 or 5335. The 531xx series seems nice ( money apart )
>> But again : which one between the 3 ? 53131, 53132 or 53181 ?
> Maybe try to get hold of one of the Philips (later licensed to
> Fluke) PM6680 or PM6681? These are more common in Europe than
> in the US, so the big US dominated websites/forums/.. don't
> mention them that often. Solid devices that can be had as low
> as 300€ if you are willing to wait, 500-800€ is the usual going
> price. The SR620 is the workhorse that drives a lot of the
> time and frequency metrology worldwide and can be had new and
> used (new on http://thinksrs.com goes for 800-2000€ used).
>
> If you go for a new one, I would consider looking at the
> Pendulum CNT-90 and CNT-91. (Pendulum is the company that
> took over Philips frequency counter business and the CNT-90
> is the continuation of the PM668x line, also sold as PM6690
> by Fluke)

Let me correct on the history and geniology there.

Philips had a instrument making side called Philips Industrier Järfälla
that did a range of measurement instruments. Later they joined forces
with Fluke. Later Philips felt that the business unit was a bad fit to
stay in Philips, so they sold it off to become a separate company which
became Pendelum. Pendelum was really the business unit with people etc
through that process, and the Fluke relation and rebranding continued.
Naturally Pendelum moved out of the Philips Industrier Järfälla office
over to Bälstabro (both locations in north of Stockholm) as it was sold
off. Pendelum also managed to rebrand their counters to Tektronix, which
mainly consisted of cosmetic changes to get the look and feel. Pendelum
was operated for many years like this, some of their production in
Pajala, where as other where done in Bälstabro. Later they reshaped the
production so that it moved to Poland where it remains. Pendulum was
sold to Spectracom and was operated as a subsidary for a while, until
they shut operation down.

The CNT-80/81 (PM 6680 and PM6681) production went on as long as they
had the timing ASIC. The CNT-90 (100 ps) was developed to the CNT-91 (50
ps), where the later replaced the CNT-81 (50 ps). They aimed to do the
CNT-92, but could not at that time do it with the same technical setup.
They also had the Wander Meter WM-10 which aided in testing telecom
sync. After some testing, I suggested they would broaden the product to
handle more signals and that is when they mostly firmware upgraded it to
the WM-11, and first time I tested the WM-11 the second '1' was cut out
from another '10' print and put over the '0'. Also, it was still under
development. Several years later they where still going back to my list
of feedback. They later did a revamped this into a new instrument with
even improved capabilities such as interfaces boards. This was later
sold off to Calnex which sells it as Sentinel, which is a great product
for telecom operators.

I still have contact with some of the Philips/Fluke/Pendelum staff and
owner.

Cheers,
Magnus