Question re BNC/Coax assembly

[Brian - N5BCN]

Hello all,

Yes, my beginner status is revealed to all as I need help with the most basic of ham operations: putting a connector on coax!  It's a testament to the quality and ease of the K2 kit that even I could get it assembled and working.

I have RG-8X coax and purchased a number of "clamp on" style BNC connectors (these are the ones with a back nut, compression washer, ferrule, and connector body).  With the little information I could find on the Internet, I got the connector assembled with the center pin soldered to the conductor and the braided shield folded back over the ferrule.  Back nut and body then tightened down.  However, the entire outside body of the connector can "spin" around coax.  Not easily, but I can certainly turn the entire connector around the coax by hand.  This doesn't seem right.  I would have expected the pressure of the connector on the braid and ferrule would have prevented this from happening, but I can't turn the nut any tighter than it is.

The assembled cable checks out ok continuity-wise, and I've used it successfully with the K2 with no problems.  However, mechanically I don't know if it will hold up.

Please let me know if I've done something wrong.

Thanks!

73

Brian - N5BCN

[Don Wilhelm-4]

Brian,

Is the nut fully threaded into the connector body?  If not, things are
not tight inside, and the ferrule is not seated.
The most common cause is that the cuts made on the outer cover and the
inner conductor are not the right distance apart.  These cutting
dimensions are critical for BNC and N connectors - close is not good
enough.  Be certain your connector conforms to the "standard" cutting
dimensions, and if not, you will have to have the cutting dimension data
for that particular connector.
The ARRL Handbook has dimensions to use for standard BNC (and type N)
connectors.

73,
Don W3FPR

Brian - N5BCN wrote:

> Hello all,
>
> Yes, my beginner status is revealed to all as I need help with the most
> basic of ham operations: putting a connector on coax!  It's a testament to
> the quality and ease of the K2 kit that even I could get it assembled and
> working.
>
> I have RG-8X coax and purchased a number of "clamp on" style BNC connectors
> (these are the ones with a back nut, compression washer, ferrule, and
> connector body).  With the little information I could find on the Internet,
> I got the connector assembled with the center pin soldered to the conductor
> and the braided shield folded back over the ferrule.  Back nut and body then
> tightened down.  However, the entire outside body of the connector can
> "spin" around coax.  Not easily, but I can certainly turn the entire
> connector around the coax by hand.  This doesn't seem right.  I would have
> expected the pressure of the connector on the braid and ferrule would have
> prevented this from happening, but I can't turn the nut any tighter than it
> is.
>
> The assembled cable checks out ok continuity-wise, and I've used it
> successfully with the K2 with no problems.  However, mechanically I don't
> know if it will hold up.
>
> Please let me know if I've done something wrong.
>  
>

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[Brian - N5BCN]

Hi Don,

The nut is cinched down extremely tight, but I doubt I was very careful with the cut dimensions.  I'll check that next.

73

Brian - N5BCN  

[AC7AC]

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