Author Topic: FS: 8 GHz Input C option for PM6680, PM6681 and PM6685 frequency counters  (Read 1590 times)

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Offline jadewTopic starter

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Hey guys,

I just started selling these boards on my website: https://cojotech.com/pmo-080

A video and installation instructions should be available sometime next week.

I made a mistake on the silkscreen (which is not visible in the photo, because I photoshopped it out), so the boards from this batch will have a little sticker where the part number and the serial number is, which will specify the correct part number (this was the mistake).

15% off on this batch.

Cheers!
« Last Edit: August 10, 2019, 04:51:45 am by jadew »
 

Online alm

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I realize this is an old topic, but posting this question on the forum should be more helpful to others than emailing you directly. I'm considering ordering one of these. Why the choice between 20cm and 30cm cable? Surely there will be an optimal length based on the position of the front panel connector and prescaler board? Or is there a difference between the PM6680/6681 and PM6685? I believe the '85 might have the prescaler board in a different position than the other counters.

Also, the board should also work with the Pendulum CNT-80/81/85, since as far as I know these are identical to the Fluke/Phillips counters, and were rebranded after Pendulum split off from Fluke (similar to Agilent -> Keysight).

Offline srb1954

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I'm considering ordering one of these. Why the choice between 20cm and 30cm cable? Surely there will be an optimal length based on the position of the front panel connector and prescaler board? Or is there a difference between the PM6680/6681 and PM6685? I believe the '85 might have the prescaler board in a different position than the other counters.
On the PM6681 a different length of cable required for the front panel or rear panel installation of the channel C connector. I found (with a different after-market prescaler to this one) that the 20cm cable wasn't long enough to reach the front panel but was OK for the rear panel.
 
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Offline jadewTopic starter

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Sorry for the late reply, I missed the notification.

Indeed, on the PM6681 the 20 cm cable is not long enough. I will give up entirely on the 20 cm cable option as the difference in response between the two is negligible.

I also have some new 30 cm cables on order, which will be of higher quality, so once those are here, the choice will be between low cost 30 cm and high quality 30 cm cables. The main difference will be in the build quality and materials.

Regarding the Pendulum counters, yes, it should work there as well. It even works in the CNT-90 - had a customer who installed it in one but I think the connector didn't fit quite right and he had to shave two corners of the connector with a file.

As I'm writing this, I'm out of all types of cables, but I'll have some of the high quality ones in stock as of next week.

Edit: I have completely given up on the low cost cables.
« Last Edit: July 23, 2021, 06:11:23 am by jadew »
 
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Offline ytterligare

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Hi there, slightly off topic but I wanted to testify that I got from you the 10 Ghz board for the HP 53131A and it is working beautifully, thank you !!  :-+

Andrea
 
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Offline nctnico

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Regarding the Pendulum counters, yes, it should work there as well. It even works in the CNT-90 - had a customer who installed it in one but I think the connector didn't fit quite right and he had to shave two corners of the connector with a file.
That is interesting. I'm wondering if it would also work in the CNT-91 (I have the Tektronix branded version of that counter).
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline jadewTopic starter

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Hi there, slightly off topic but I wanted to testify that I got from you the 10 Ghz board for the HP 53131A and it is working beautifully, thank you !!  :-+

Andrea

Hey Andrea, thanks for the testimonial! :)

I was going to get in touch with you once I received the new 30 cm cables, because there's a connector in that order that might be of interest to you.


Regarding the Pendulum counters, yes, it should work there as well. It even works in the CNT-90 - had a customer who installed it in one but I think the connector didn't fit quite right and he had to shave two corners of the connector with a file.
That is interesting. I'm wondering if it would also work in the CNT-91 (I have the Tektronix branded version of that counter).

It will most likely work. I just checked my messages and at least two customers got them for their CNT-90s (edit: and it worked).
« Last Edit: June 12, 2021, 10:14:50 am by jadew »
 
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