Re: [AMMRL] Varian VT Connector Fix

Just to briefly chip in:

- indeed out of all bad DB9-style connectors the ones used in 400MR consoles is the least bad: instead of the infamous side clamps (which never held) they use nonmagnetic long serrated screws which hold on much better - at least on newer style probes. Older ones have that stupid unreachable counter-screw reaching into the very same hole much further, leaving only 1-2 turns for the outer screw to hold onto… Grrr…

Good: one can find nonmagnetic DB9 housings which you can easily mount instead of the standard plastic one.

- indeed pins 2&3 (IIRC) should be copper and constantane

- unfortunately the final fix (standard large blue thermocouple VT connectors) were introduced around beginning of 2014 only, so only very few of these probes were ever made before Agilent kicked the bucket later that same year…

Cheers

Bert



Hi Bruce,

 

In the files section of ammrl.group.io, there are a number of hardware manuals. The pinout you are looking for is on page 10 of the Highland VT controller manual. Note that two of the pins need to be type T alloys, not the standard copper of replacement DB 9 connectors.

 

https://ammrl.groups.io/g/main/files/Hardware%20Manuals/VarianAgilent%20Hardware%20Manuals/L900_Highland_VT_Controller_2009.pdf#page=10

 

From the manual:

4.2.1 Probe Connector J101 (Rev C Units) 
The rear-panel 9-pin probe connector J101 is a female, 9-pin D-SUB type. The two thermocouple-input pins 
are of type 'T' alloys, and the mating connector must have corresponding thermocouple alloy crimp pins. 
Pinout is as follows: 

1. Thermocouple + Copper wire/pin alloy 
2. Ground 
3. Thermocouple -Constantin wire/pin alloy 
4. n/c 
5. n/c 
6. Heater highside drive 
7. Heater lowside drive (ground return) 
8. Safety R TD low side 
9. Safety R TD high side

 

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