Best connector for AF square waves?

Jun 23, 2011 9 Replies

Gentlemen:



I have a number of shielded, single-center-wire, small-gauge (.100" OD) cables that are transmitting square waves at audio frequencies (20-5000 Hz). I need to connect them to a PCB circuit with a plug/ jack each. I need to ground the shield at the jack end and the wave must remain crisp and noise-free.



What is the best connector to use for this? BNC? RCA? Phone Plug? Other? I need to keep it cheap and small since there are almost 100 cables.



Thanks for any replies.



Don


F connectors are relatively cheap and also easy to install, if they'll fit your cables. Do the cables have an "RG" designation?

Rich Webb Norfolk, VA

Any of those is way too clunky for a little delicate 0.1 OD shielded wire. Is it "coax," i.e., does it have a published impedance? Digi-key has 4526 choices; here's a selection guide:

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If it were me, I'd start by looking up some of those connector types, and find the smallest I could, and so on - ordinary product research.

Good Luck! Rich

?

Don, I don't think the type of connector you choose is going to make much difference. Unless it's high voltage or high current.

George H.

At audio you can use the header connectors like on a computer motherbord. Berg is the brand we used at Microdyne. If the cables always connect to the same place yo can use a lager version and put several or even a dozen cables per connector.

It's easy to think outside the box, when you have a cutting torch.

.1" sounds like RG/174 and is too small for F connectors. It also has a stranded center conductor.

It's easy to think outside the box, when you have a cutting torch.

Is this about 100 cables into a SINGLE printed circuit board? And each has to be separate, i.e. cable retention provisions have to be one-at-a-time? If you want a PCB in the ten inch size range, that means connectors will only have 0.1" center-center spacing available.

There are rectangular connector systems that can mate dozens of coaxial pins, with jackscrews to pull it them all together and force 'em apart when you want to detach. Would that work for you?

RCA is probavly the cheapest option and gives acceptable performance upto several megahertz eg: it's used in consumer video equipment.

2.5mm phone plugs could be more compact, but they tend to give worse contact .
?? 100% natural

I ended up replacing the cables with standard, molded RCA cables (like for audio). I cut one in half to make two cables, solder the pigtail end at the source and use individual grounded RCA jacks at the other end. I makes for a rather large PC board, but not too bad. I'll let you know how it works out.

Don

Gentlemen:

I have a number of shielded, single-center-wire, small-gauge (.100" OD) cables that are transmitting square waves at audio frequencies (20-5000 Hz). I need to connect them to a PCB circuit with a plug/ jack each. I need to ground the shield at the jack end and the wave must remain crisp and noise-free.

What is the best connector to use for this? BNC? RCA? Phone Plug? Other? I need to keep it cheap and small since there are almost 100 cables.

Thanks for any replies.

Don

Just curious. What are you doing with the square waves.

If its data the line length and the type of medium will be more important than the connectors. Just curious.

Tom

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