Author Topic: Tight SO-259 connectors  (Read 1887 times)

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Tight SO-259 connectors
« on: June 17, 2012, 08:24:48 PM »

I have a few bulkhead feed-through adapters (UG-363 type from Universal-Radio) that are SO-259 at both ends and they are TIGHT! I can barely force in a PL-259 and then when I try to remove it the center pin and insulator get pulled out and the cable is ruined. I have tried more than a few cables on these feed-throughs and they are all tight. I don't see that I'm doing anything wrong, but I may be missing something since I have three of these things and they are all the same. IS there some kind of lube that should be used? Are they all defective? My cables fit fine in all of my radios, SWR bridges, etc., but they don't fit in these feed-throughs.

ETA: it appears that I was wrong on the other two feed-throughs. They do seem to fit my cables properly so I only have one that is out of spec. I'd like to fix it if possible and they only way I can think of to do that is to ream the inside out and I doubt that will be successful without messing up the contacts since it is kind of a collet going on in there.

If anyone has any ideas how to open this thing up just slightly I'd like to fix it instead of junking it. Maybe some fine grit sand paper in a roll?


« Last Edit: June 17, 2012, 10:31:35 PM by SOPMOD »


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Re: Tight SO-259 connectors
« Reply #1 on: June 18, 2012, 08:14:52 AM »
I wouldn't recommend a lube or reaming it out with anything abrasive. There isn't much metal involved in there as it is and you certainly don't want it loose.

One thing you might check for is to see whether it's tight, or just out-of-round. Maybe you have a notoriously easy-to-plug PL-259 that could help put it back in spec; some of the pre-packed patch cords found in truck stops have the pointy-end PL-259 on them. Any regular PL-259 that's got ANY hint of solder left on the tip/shaft that is OUTSIDE the dimensions of the shaft is going to keep it from getting in a properly sized socket. This stuff happens and I've bought quantities of connectors/sockets, some more "in-spec" than others. (If you bought it direct from Universal you should just call them & have 'em send you a new one.)

If you know it's not out-of-round but truly undersized really you can either just junk it or find a similarly undersized PL-259 that likes it.