Care and Feeding of Copper Banana Jacks - Page 1
Forum section: electronics / testgear

author: d-smes
author_rank: Regular Contributor
timestamp: December 11, 2015, 05:19:13 pm
content: I have a new Keysight 34465A DMM that has Copper Alloy input terminals (according to the data sheet). What is the alloy and how well does it resist oxidation? Would I delay oxidation if I insert dummy banana plugs in the unused jacks? Or would a plastic cover over the jack hole be enough? Or is this a pointless concern? I'm curious what others here do (if anything).For cleaning the jacks, I've read Caig Laboratories' DeoxIT is recommended. How does one wipe or scrub the inner banana jack surface? Pipe cleaner sticks? Fabric over a small wooden dowel or match stick? Or do you simply insert a test lead and give the banana plug a few twists? Again, I'd appreciate your advice and recommendations.

author: timb
author_rank: Super Contributor
timestamp: December 11, 2015, 06:01:41 pm
content: I use Swab-Its foam swabs to apply DeoxIT, then work a banana connector in a few times, let sit for 5 minutes and remove the excess with a clean Swab-It.Avoid Q-tips or cotton swabs as it can leave behind lint.Sent from my Smartphone

author: d-smes
author_rank: Regular Contributor
timestamp: December 12, 2015, 12:57:56 pm
content: How quickly do your jacks become oxidized? Or do you clean them as part of weekly/monthly maintenance?

author: robert_
author_rank: Regular Contributor
timestamp: December 12, 2015, 05:12:56 pm
content: Not fast at all.I highly doubt they were ever cleaned on my ~10year old 34401 and are not significantly (i diont how how polished these were to begin with) discoloured.At least, its not much of a problem, when shorted with gold plated 4mm connectors (gold on CuO should be rather bad in term of thermal offsets) i measure below 1uV of offset, well below the 34401s uncertainty.Wouldnt waste time and effort on cleaning these too often, only if you really need the highest level of precision.

author: d-smes
author_rank: Regular Contributor
timestamp: December 12, 2015, 08:08:54 pm
content: Quote from: robert_ on December 12, 2015, 05:12:56 pmGood to know. My guess is Cu is alloyed with 5% Zinc (ASTM B36). Any more Zn and jack would start looking like brass. I'm no chemist, so I don't know if this is enough to retard oxidation. Whatever the alloy, it seems oxidation is not an issue or I would have received more replies.

author: Cerebus
author_rank: Super Contributor
timestamp: December 13, 2015, 02:41:49 am
content: The usual alloying elements for high quality copper plugs and sockets are beryllium and tellurium. Beryllium is more common and tellurium is usually reserved for proper high end stuff, often with a hard gold plate over the top. Typical alloying level is around the 5% mark for both elements.

author: macboy
author_rank: Super Contributor
timestamp: December 14, 2015, 01:01:27 am
content: Quote from: Cerebus on December 13, 2015, 02:41:49 amNo, Copper Tellurium is usually around 99.5 % copper and 0.5 Tellurium.

author: timofonic
author_rank: Frequent Contributor
timestamp: December 28, 2015, 10:05:28 pm
content: Are there a way to know the compounds easily? I did see gold buyers use a two LED device to check conductivity, green is gold and and red is something else.

author: Fungus
author_rank: Super Contributor
timestamp: December 29, 2015, 05:37:25 am
content: Quote from: d-smes on December 11, 2015, 05:19:13 pmYou'd think Keysight would know a bit about oxidation and choose a suitable metal alloy.(On the inputs of a DMM I mean, not their metal boxes...)