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How do you terminate your coax to BNC?

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PekkaNF:
Cripping looks pretty easy on video


Looks like much of to confusion comes from manufacturer documents. They simply can't convert imperial unit int metric units. This combined with my deep distrust on spesifications and sales information makes desission making unncessary hard for me.

Looks like good brand RG174U cable can be crimped to TE BNC connector with HT336G plier.

Looks like minimum order for the quality RG174 cable I want is 250m. Therefore I'm considering  alternatives:

1: RG316U HELUKABEL 40203 3.39 €/m in 5 m increments.
https://www.tme.eu/fi/Document/151b7fc68e82e16d70ee1f3bf3c18100/M_004-005-006-007_RG-coaxial_cables.pdf

2: Belden 9239, looks expensive (1.97 €) for what it is (RG174U/PVC), but can get 30,5m reel.
https://www.tme.eu/fi/Document/32871dfd99d2b35ed5387313722281b3/9239.pdf

Thinking of 10 metres of #1 to start with. Any reason why #2 would be better for short measurement test leads?

Pekka

PekkaNF:

--- Quote from: eskoilola on February 24, 2018, 02:46:53 AM ---Making pigtail on a coax cable is quite easy. I found a video in YouTube which shows the method I have been using - the only difference being that I bend the coax shielding backwards and make the joint over the coax insulation.
The pigtail needs some support and insulation. Shrink tubing is OK but for better durability I use plastic tube over the end of the coax, gaps filled with Sikaflex. The Sika creates a flexible joint which makes the wires last longer.

The Youtube video is here.

--- End quote ---

Thank you, that video reminds me of LiFYCY/shielded control cable termination I did as a electrician trainee. No-one ever answered why normally we had to solder pigtail on instrumentation cable shield, even when termination would haven been neater with isulation sleeve and crimp ferrule at the end. Except on one "robot" that were required to clamp down the outer shield, shrink tube to keep all together and inner shield shelds had to be knited out like that on video, crimped and tightened under screw terminal.

I have to think of that fold back shield pig tail. It might come handy son some thight places.

PekkaNF:
Got cable, connectors and a pliers, but haven't terminated cables yet. Have to find the crimp dimenssions to test the connection. At work we used to check pliers when new and then every 1000 crimps or so. I never did BNC-connectors, but belive that crimp connector is a crimp connector.

Now the next problem: There are plenty on 50 ohm BNC connectors for PCB and panel mounting. Even panel mounting with both connectors as a solder luggs (and isolated). But very few male connectors for any other than cable. I know that there are very little need for it, but when making probe contraptions for oscilloscope, they would coe handy.

There are some chinese ebay stuff, but I really rather buy brand name stuff that connects to oscilloscope.

I found some, but silly price:
https://www.digikey.com/product-detail/en/hirose-electric-co-ltd/BNC-BPR-3-40/H122549-ND/5148473

Probably could use probe compensator, but that would effectively wreck a good probe.



NO-NOT-that one, but that kind of "box"

eskoilola:
Are You afraid that the Chinesium somehow contaminates the oscilloscope ?

It is just a connector after all. Some of the dimensions are critical and maybe there should be a layer of precious metal here and there and maybe some of the insulators should be made out of something like Teflon. But, unless You are going to make something that enters the orbit the ones made of Chinesium perform just as good as the brand name. And, in the worst case, the brand name components might be manufactured in the very same factory as the cheap ones, there is just this label...

PekkaNF:
Your concern about contageneous properties of cihinesium are founded.

However toxcity for my allready tainted Rigol DS1052E is not lethal, IMHO. It might be a different case if it were western made, then I would not bring any products from far east near it.

I am concern that connector would not fit properly and would wear out BNC:s on my scope.

Another thing is that ebay stuff is pretty low quality in general. Today I found a 50ohm terminator that didn't terminate (it had a stadard small resistor inside it, but the connection was not made... AND few days ago I fount that one BNC/screw terminal adapter had a deformed coupling nut. Seriously oval. mad to give them a spin in the lathe.

I have seen abysmaly bad enginering from pretty much any country I have been working. And some good one. It's just pretty hard avoid buying crap, no matter what brand. Alhough some brands are pretty good on peace of mind department, but on electrical stuff they commad price that I can't afford. For me it is harder to find a decent quality stuff, spesification must be sacred, I don't care all the features and usually I don't need latest and greatest stuff.

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