SO-239 Concerns -- Another Perspective

Posted by Joel R. Hallas on Jul 23, 2010; 1:23pm
URL: http://elecraft.85.s1.nabble.com/SO-239-Concerns-Another-Perspective-tp5329637.html

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

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