VHF coax connector needs help

FourPoints · May 6, 2014

While I 100% agree with Fred about the LMR cable (I used to do a lot of commercial wireless work and can absolutely attest to the water wicking comments above). I'm unclear which non solder connectors you guys are suggesting actually work well.

I need to replace my mast coax sometime fairly soon, and if there is a good non-solder (or just tip solder) connector that is recognized as being reliable I would love to know.

Brian D · May 6, 2014

Brian, although this may not answer your question as to which brand connector, any connector that affords the most physical/electrical connection to the braid is better than one that affords little physical/electrical connection. Regardless of which one you get, make sure that in the long run you give in environmental protection to ensure it will last longer.

Fred Villiard · May 6, 2014

Without knowing what cable you are using, can't recommend a specific connector.

look in DX Engineering, Texas Towers,Pasternak, Digikey, Mouser, Newark, or Allied are a few suppliers. Texas Towers is a good sorce for LMR coax and they will put the connectors on one or both ends and their workmanship is excellant. Pasternack connectors are house brand Amphenol and Molex.

I would not recomend any of the clamp style for the mast head, just the crimp.

Hope this helps
Fred Villiard

FourPoints · May 6, 2014

Not sure what cable I'm going to use, but it won't be the huge heavy cable. Mast is only ~35ft so no need for the real heavy coax, plus it wouldn't fit through the existing holes in the mast.

I prefer sold conductor core, but probably just because I used to crimp loads of Times Microwave LMR-600 cables where the center conductor was aprox the size of 10awg wire (seriously, we would by the connectors in bags of 100 at a time, and they would last only about a month, and we bought the cable in 1000' spools which I suspect weighed about as much as a Ford Econoline Van).

I think my existing cable in the mast may be RG-59, but I guess 8X is preferred since it's lower impedance, correct? I should be able to fit the 8X up the mast conduit without too much trouble...

So which connectors are best for either the RG-59 or the 8X?

FourPoints · May 6, 2014

CharlzO said:
I used one of these for my deck connector...

CharlzO, You're welcome... Without me you probably would not have been able to buy that connector without having first taken a trip to Europe. :cussing:
http://sailingit.com/blog/boat-projects/vhf-deck-fitting

CharlzO · May 6, 2014

Very cool, and definitely thanks for that effort! I love the fitting, it was exactly what I was looking for.

(And yes, I realize that they sit almost a foot away from the foot of the mast. But the beam under the mast is 2" thick, possibly more, and I didn't want to have to carve out a huge hole to run connectors into. So they did have to move down to where I had better access. There is a slight risk of tripping on them, but I'm pretty confident that it won't happen unless someone isn't watching what they're doing.)

CharlzO · May 6, 2014

Does make me think...I can't think of a time I've ever seen a Female PL259 connector for cable ends....

To hit on the other side though, I think you may have been questioning your connector having such a rounded center pin, versus the ones that typically are shown. It really isn't anything special, just happens to be that particular model connector from whatever mfr it is.

Maine Sail · May 6, 2014

CharlzO said:
Does make me think...I can't think of a time I've ever seen a Female PL259 connector for cable ends....

.

A female version of a PL-259 is called an SO-239...

CharlzO · May 6, 2014

I should've clarified - I meant an inline version. But after the SO-239 reference, I DID find (not many but..) a few. Well, one so far, but still...

I'm used to seeing chassis mounts, and adapters, but the actual crimp on ones are fewer and far between. Just would expect to see them more often.

Thanks for reminding me of the 239. I completely forgot about that!

Chris Patterson · May 7, 2014

Yeah Dawg, again, not uncommon. Those old SO239 'barrel' connectors have been around for years. Years too long I might add. Mostly the only time I have ever seen a female,(SO239), end on a cable it was for extending it. There again, that is not recommended. Coaxial is finicky stuff actually. I have heard, and I don't believe it, but every transition is a 10% loss. I think this comes from the power transmission crowd that says you have the 10% loss in every regroup of drive. Anyways...no, you will not find many cables with a female end. Most connect at the transceiver and resonating element by the PL259. Or BNC, TNC, 'N', whatever. These coax companies assume if you need longer coax, throw away what you have and buy a longer piece. Too much loss and failure potential with two connectors, plus the barrel.

For what it is worth, I wish the industry had went with the more stable 'N' connector. But like cigarette lighter plugs, 30 amp twist-locks, Motorola and RCA connections, these old turkeys persist. Go figure..

FourPoints · May 7, 2014

Chris Patterson said:
I have heard, and I don't believe it, but every transition is a 10% loss.

It depends heavily on the frequency of the transmission signal, and the connector type, but it can actually be higher than that.

Chris Patterson said:
For what it is worth, I wish the industry had went with the more stable 'N' connector. But like cigarette lighter plugs, 30 amp twist-locks, Motorola and RCA connections, these old turkeys persist. Go figure..

FWIW, 'N' connectors are a real ***** to get completely tight. The threads are pretty fine and offer a lot of friction, and any little bit of crud on them will result in them only getting partially tightened (see previous commend about the number of commercial RF connectors I did, with few exceptions they were all 'N' type).

A partially tightened 'N' connector will easily work loose over time from vibration or thermal changes, and they still leak water despite the rubber seal. We always needed to seal the entire connector area by wrapping everything with a layer of electrical tape, followed by a few wraps of mastic tape (essentially a cheaper version of butyl that would destroy the deck of a boat with the nasty streaks it would leave, the first layer of tape was to protect the connector from the mastic), and finally with another layer of electrical tape to keep the mastic tape from making too big of a mess.