[Elecraft] SO-239 Concerns -- Another Perspective

[Eric Scace K3NA]

    The "turn of the screw" method for tightening (used for many nut and 
bolt fasteners) is appropriate with UHF connectors: firm finger tight, 
and then use a tool (pliers) to tighten an additional quarter-turn.

    If you can remove the shell without using a tool, it's too loose.

-- Eric K3NA

on 2010 Jul 23 09:23 Joel R. Hallas said the following:
> I agree with most of what has been said in support of UHF connectors for HF
> and low VHF -- with two reservations.
>
> 1. Many SO-239s provided as part of radio equipment are not up to the
> quality of Amphenol units. In particular, the spring fingers of the socket
> for the male pin loosen over time to the point that the connection becomes
> less than solid. This is particularly a problem if the connector is used
> repeatedly. I usually replace with Amphenol units, if I can get to them.
> Another great option is the Oak Hills BNC kit, designed to fit the hole
> pattern of the SO-239.
>
> 2. The other potential problem with UHF connectors, in my opinion, is the
> integrity of the shield connectivity through the connected pair. If the
> backshell loosens, there is no longer a solid connection either at the
> toothed parallel portion, nor through the backshell. This can be an issue in
> mobile or other high vibration environments and has caught me many times.
> Note that a type N, C or BNC pair makes it's shield connection through the
> inner spring tension sleeve, maintaining contact almost until the pair
> separates. The backshell is just used for mechanical, not electrical,
> purposes.
>
> FWIW
>
> Regards, Joel
> Joel R. Hallas, W1ZR
>