Author Topic: DIY Low EMF cable and connectors  (Read 66956 times)

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Offline quarks

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DIY Low EMF cable and connectors
« on: February 08, 2013, 02:05:18 pm »
Hello all,

for quite some time, I am experimenting with Low EMF connections/cables. I have different things allready tested and found this crimp spade lugs from AMP (see picture) to be very good. Unfortunately I cannot find it on-line. Does anyone know the partnumber of it or a place where I can find it?

thx
quarks
 

Offline grenert

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Re: DIY Low EMF cable and connectors
« Reply #1 on: February 09, 2013, 06:56:19 pm »
Sorry, can't help you with that particular part, but I see that Mouser carries Pomona low EMF lugs with banana plug inserts:
http://www.mouser.com/Search/ProductDetail.aspx?qs=LxJU1xRJL0GNFHRHCmLa5A%3D%3D
 

Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #2 on: February 09, 2013, 07:34:52 pm »
Sorry, can't help you with that particular part, but I see that Mouser carries Pomona low EMF lugs with banana plug inserts:
http://www.mouser.com/Search/ProductDetail.aspx?qs=LxJU1xRJL0GNFHRHCmLa5A%3D%3D
Thx a lot grenert,
I know the Pomona low emf parts and it is good to know where to get them outside of the USA.
For my actual DIY low emf experiments I look especially for crimp spade lugs pure copper (pref. Gold plated and/or with tellur) with low thermal mass (for fast equilibrium; I hope that is the right word).
All the parts I found and tried are either heavy Audio versions or tinned copper versions.
The above showed AMP is so far the best match to what I want.
« Last Edit: February 09, 2013, 07:38:21 pm by quarks »
 

Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #3 on: February 13, 2013, 09:38:51 pm »
Is there anyone else, interested in this topic?
If yes, I will keep on asking and posting. 

So far I found this article very good "Metrology 101 - Watch out for those Thermoelectric Voltages!" (see link)

http://us.flukecal.com/literature/electrical-calibration/watch-out-those-thermoelectric-voltages-cal-lab-journal-reprint

If anyone has more useful ideas, how to do more tests, please share.

With grenerts good hint, I ordered at mouser some Pomona Low EMF stuff.
I made already quite a few comparisons and will keep on testing.

PS: Still hope to get a hint for the AMP spade lug or something similar!
 


Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #5 on: February 14, 2013, 05:28:48 pm »
Hello robrenz,

thx for your reply. I probably should have said, that I already have all the Pomona Low EMF parts I could find. I bought them, because it is always good to have a reference.

But what I would like to do, is to find out / learn  how to measure the effects and what is the best method to do it and finally how my DIY cables will compare. Suggestions are welcome.

Here are some parts I work/test with right now (see picture). As soon as I find the spade lugs, I look for, I will make some sample cables with crimped connectors and different cable types (twisted pair, audio, coax and what ever I find worth testing).

bye
quarks
 
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Offline grenert

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Re: DIY Low EMF cable and connectors
« Reply #6 on: February 14, 2013, 05:30:40 pm »
National Instruments has a rather expensive kit with some similar lugs along with other useful parts:
http://sine.ni.com/nips/cds/view/p/lang/en/nid/202766

They also have a nice white paper on thermal EMF focusing on switching:
http://www.ni.com/white-paper/4199/en
 
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Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #7 on: February 14, 2013, 05:38:45 pm »
Hello grenert,

thx again. I will read through the article. The shown parts look quite similar to what I have (probably some or most is from Pomona).

bye
quarks
 

Offline andyb

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Re: DIY Low EMF cable and connectors
« Reply #8 on: February 15, 2013, 02:52:08 pm »
Quarks, I wanted to let you (and others) know that I too have been bitten by the low thermal EMF bug and have been searching around for similar parts. I however, have been looking for

  • Suitable cabling - PTFE insulated, 4 conductor oxygen free with shielding braid
  • Low EMF relays - automated Kelvin-Varley divider, voltage reference scanner
  • Solder

I have some preliminary candidates for each, but am still looking. As a note, Indium still manufactures Cadmium bearing solders (though not as pastes - health concerns).
 

Offline grenert

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Re: DIY Low EMF cable and connectors
« Reply #9 on: February 15, 2013, 03:19:09 pm »
All of the teflon wire I've seen is made of silver-plated strands.  Shouldn't that create a thermocouple?  Have you found pure copper Teflon cables?
Mouser carries low EMF relays.
Personally, I would rather have excess thermal EMF than mess with cadmium  :scared:
 

Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #10 on: February 15, 2013, 03:53:53 pm »
All of the teflon wire I've seen is made of silver-plated strands.  Shouldn't that create a thermocouple?  Have you found pure copper Teflon cables?
Mouser carries low EMF relays.
Personally, I would rather have excess thermal EMF than mess with cadmium  :scared:

Copper-Silver should be ok and is suppose to have the same 0.3µV/°C as Copper-Gold. But Silver will have oxidation and I do not know how this will influence.
I have ordered PFTE RG196 coax and will check it out.
Cadmium also scares me and is probably not allowed to sell/buy in Germany. Therefore I will definitely crimp my Low EMF cables.


Quarks, I wanted to let you (and others) know that I too have been bitten by the low thermal EMF bug and have been searching around for similar parts. I however, have been looking for

  • Suitable cabling - PTFE insulated, 4 conductor oxygen free with shielding braid
  • Low EMF relays - automated Kelvin-Varley divider, voltage reference scanner
  • Solder

I have some preliminary candidates for each, but am still looking. As a note, Indium still manufactures Cadmium bearing solders (though not as pastes - health concerns).
I have not seen PFTE with 4 conductors. If you find some, please let us know. But maybe you should also look for 2-conductor ones.

So far I found/read that Belden 8422 (2 conductor shielded) is very good, but I have not yet found a source selling only a few meters.
Or if it has to be 4-conductors, try out Conrad Hoffmans secret tip with Telephone Twisted Pair cable.
« Last Edit: February 15, 2013, 03:57:49 pm by quarks »
 

Offline andyb

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Re: DIY Low EMF cable and connectors
« Reply #11 on: February 21, 2013, 03:49:22 pm »
I'm gonna send an email to these guys

http://jswilley.com/Accessories.html

Who sell low EMF wire, binding posts, spade and ring lugs. They're in Florida USA, I'll inquire about international orders.
 

Offline andyb

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Re: DIY Low EMF cable and connectors
« Reply #12 on: February 21, 2013, 05:21:37 pm »
Low EMF binding posts

Pomona 3770 (available at Mouser)
IET BP-1000
jswilley
 

Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #13 on: February 21, 2013, 06:11:11 pm »
Hello andyb,

this jswilley looks interesting. Please let us know what you found out.
The Pomona 3770 I have bought from Mouser (with all the Low EMF parts they had in stock). They shipped extremely fast (only two days from US to Germany).

bye
quarks
 

Offline PA4TIM

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Re: DIY Low EMF cable and connectors
« Reply #14 on: February 21, 2013, 06:45:41 pm »
Quarcs, on your picture I see a shielded double banana lead. Do you have a partnumber ? They would be ideal for connections between calibrators and KVs and I need them for my GR-1620
www.pa4tim.nl my collection measurement gear and experiments Also lots of info about network analyse
www.schneiderelectronicsrepair.nl  repair of test and calibration equipment
https://www.youtube.com/user/pa4tim my youtube channel
 

Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #15 on: February 21, 2013, 07:32:18 pm »
Quarcs, on your picture I see a shielded double banana lead. Do you have a partnumber ? They would be ideal for connections between calibrators and KVs and I need them for my GR-1620

Hello PA4TIM,

these are from ESI and I have two versions. On the cables is a label # ESI 9347 (length only 28cm) and # ESI 9281 (length 56cm).
I like them very much and would like to have more (with other length), but I think they are not available anymore. If you find a source please let me know.

bye
quarks
 

Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #16 on: June 13, 2013, 12:59:08 pm »
short update

about jswilley, 2758-Fork seems to be quite good (Price is 2.40$/each), they also have 4-conductor Teflon cable

If there is anyone out there who knows where to get/find the AMP gold spade lugs, please let me know.

bye
quarks 
 

Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #17 on: April 11, 2014, 08:01:58 am »
because I am still searching, here is a short update.
Does anyone know where to find these JST spade lugs?

thx
quarks
« Last Edit: April 11, 2014, 08:03:54 am by quarks »
 

Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #18 on: May 04, 2014, 03:49:43 pm »
does anyone know what the name of these or similar cable "split" parts is and where to find/buy them?
« Last Edit: May 04, 2014, 06:44:24 pm by quarks »
 

Offline robrenz

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Re: DIY Low EMF cable and connectors
« Reply #19 on: May 04, 2014, 06:28:45 pm »
I thought those type were injection molded onto the wires.

Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #20 on: May 04, 2014, 06:41:06 pm »
Hello robrenz,
when I look at them, they look like cliped together and not molded. But these cables are extreme expensive, therefore I do not want to try to open/damage them. My guess is, they are from Pomona, but they do not seem to offer them for DIY assembly.
Bye
quarks
« Last Edit: May 04, 2014, 06:43:30 pm by quarks »
 

Offline robrenz

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Re: DIY Low EMF cable and connectors
« Reply #21 on: May 04, 2014, 07:12:08 pm »
I could not find any that clip on.  My google fu is not good enough.

Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #22 on: May 05, 2014, 08:44:35 am »
here is a closeup
Does anyone know what the name for these parts is?
« Last Edit: May 05, 2014, 11:19:12 am by quarks »
 

Offline robrenz

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Re: DIY Low EMF cable and connectors
« Reply #23 on: May 05, 2014, 11:19:26 am »
I agree that looks like two pieces, not molded on.  It may be solvent or ultrasonic bonded. Is there any relative motion between the halves at all when firmly rotated in opposite directions? Even if there is it does not mean they will snap apart without damaging the snap features. The only reason I mention this is there may be manufacturers Identification on the inside of the pieces.

Offline quarks

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Re: DIY Low EMF cable and connectors
« Reply #24 on: May 05, 2014, 01:11:05 pm »
Hello robrenz,

it is showing very little movement, but I do not want to take the risk to break it.
Also I do not need the same part, only looking for something similar.

bye
quarks
« Last Edit: May 05, 2014, 03:05:03 pm by quarks »
 


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