Re: General Radio 874 Connector, inner conductor "bendies"

Richard Knoppow

I looked at a couple of 874 s just now. The tips of the small center contacts are pointed and slightly tapered toward the center. The larger of the center contacts are tapered toward the inside and slightly bent outward so that the opposing contacts slide over each other and form a continuous tube. Its somewhat the same as the outside contacts.
While the photo may be an optical illusion it does not look right. I don't think the connector was twisted but someone may have put a 274 banana plug into it and bent it. The 274 _can_ be used on an 874 but one must be careful not to stress it. The design is such that the outer shell makes contact first and pretty much prevents the mating plugs from being twisted.
The 874 is a pretty good connector but has the disadvantage of not having a precise reference plane. They can act as a short sliding line. Even when locked the reference plane is uncertain.

On 8/6/2019 2:44 PM, Roy Thistle wrote:
Hi All:
Apologies, if this has been covered (there are a lot of posts on 874!).. but the picture on Tekwiki of the GR-874 (the one with the plug facing the viewer... so you can see into it)… well that picture shows two of the leaves of the center conductor, bent in at the corners, and so having little "bendies" barbs, or tangs. (You have to see the picture!).
My initial question is… Is that normal, or is the center conductor of the connector damaged? (You can see a bit of those "bendies" on the leaves of the outer conductor, in the picture, too.) My initial guess is the matching, inserter GR-874, after being rotated, and mated, has damaged the insertee? If so, how does the mated pair maintain 50 ohms?
Best regards and wishes.
Richard Knoppow

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