RF connectors - Page 1
Forum section: electronics / rf-microwave

author: apelly
author_rank: Unknown
timestamp: August 14, 2016, 01:41:07 am
content: Every new thing I buy needs another two hundred bucks worth of cables and connectors.This time it's my radio.The research I've done shows SO239 is OK for HF.I haven't seen any outdoor SO239 connectors anywhere. Have I been looking in the wrong place?I've also read where guys have standardised on N connectors and just fitted their gear with adapters. I don't mind the sound of this, but I wonder about the insertion loss of each adapter.What arrangements have you guys come up with?

author: apelly
author_rank: Unknown
timestamp: August 14, 2016, 03:41:32 am
content: Quote from: GEuser on August 14, 2016, 03:21:07 amOK: Weather resistant.Permanent, semi-permanent, and overnight installation outside, in the rain, wind and the sun. Either connected, or unconnected at the base of an antenna, or the end of a piece of coax.How is this done?

author: calmtron
author_rank: Regular Contributor
timestamp: August 14, 2016, 09:13:11 am
content: I don't think you will find very many options that supports lying around permanently un-mated outdoors, that's why commercial/military outdoor-rated equipment have those nifty little metal, o-ring sealed dustcaps religiously screwed on to any unused connector.Regarding SO-/PL-239 connectors for outdoor use, i usually wrap the whole joint (including both coax connectors) in self-amalgamating rubber tape for moisture protection and then some UV-resistant electric tape around that - works fine for what I'm using it for but if the antennas where harder to access I'd probably look for some better solution.

author: VK5RC
author_rank: Unknown
timestamp: August 14, 2016, 12:11:56 pm
content: I don't change over the SO239 sockets on the radio but everywhere else use N connectors. I find the SO/PL connectors are very unreliable if the 'teeth' are not engaged fully and then the SWR can be poor. N type connectors rarely have this problem.It only took me a few hours of problem solving to track down a dodgy connector to make me change, one guy in my Amateur radio club won't have a PL259 on his property - he did work for the defence electronic industry! Also in general the N type seem to be better made than the PL259 but overall you get what you pay for.For my attempt at Earth Moon Earth at 1296MHz with heliax cables it is definitely 'Andrews' Ns all the way.I use the self amalgamating tape then electrical tape combo for outside joints but the climate here is not too bad.

author: SeanB
author_rank: Super Contributor
timestamp: August 14, 2016, 12:54:03 pm
content: For temporary use outdoors use a plastic bag, preferably a heavy polythene that is UV resistant, as a cover, and a cable tie and tape to keep moisture out. For sockets put a plug in there, and wrap with some pipe thread tape ( so it will not stick to the threads) and then self amalgamating tape, or the nice new silicone wrap that only sticks to itself, then wrap overall with 3M insulation tape.For more permanent use the same PTFE tape and silicone tape, but use some self amalgamating tape over the outer, followed with the 3M tape. After a few years when you cut the tape the inner is still shiny bright.

author: GreyWoolfe
author_rank: Unknown
timestamp: August 14, 2016, 01:27:20 pm
content: Plus 3 for amalgamating tape and electrical tape over it. Probably no need to mention it, but if the coax is vertical, wind the tapes from below the connector up so the overlap is facing down instead of up.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: August 14, 2016, 01:43:51 pm
content: How about some details ?Contact your favorite supplier and ask for a chart , this lets you match the connector for the use , like Frequency - power - how many connections before degrading etc.For HF the 239/259 the silicone tape & cover with UV electrical make for good outside use & take apart for maintenance .

author: apelly
author_rank: Unknown
timestamp: August 14, 2016, 10:01:10 pm
content: Quite consistent responses. Thanks guys.I was asking because I expected this to be a solved problem. It looks like the actual solution is to avoid connectors outside.element14 lists some different kinds of self amalgamating tape:Here. I didn't expect that.Advanced tapes, Pro power and 3M. Backing is one of Polyimide, Ethylene Propylene Rubber, Polyethylene, "Rubber," or Polyisobutylene.Any suggestions on this front? My experience with all tape is that it never lives up to expectations.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: August 15, 2016, 12:36:38 am
content: I bought a large envelope or roles and different colors for about $2 ea. on ebay .Works very well , I even did a test by raping a 239 connector with a few layers , and within about a minute or I grabbed the end with a needle nose and tried to unroll , it wouldn't , the last layer actually spilt in half , rather than one layer coming off the next .

author: Electro Fan
author_rank: Super Contributor
timestamp: August 15, 2016, 12:40:27 am
content: My experience with this stuff is limited but I've developed a preference for N connectors (vs UHF SO239/PL259) where possible inside and especially outside. If you can avoid connectors that might be a better solution; might depend on the overall equipment and system design. (I've also found that even among N connectors the materials and machining quality of connectors can vary; some seem more precise and durable than others.) Either way, for permanent outside installations tape wrapping seems like a good idea.

author: tautech
author_rank: Super Contributor
timestamp: August 15, 2016, 02:02:16 am
content: Quote from: apelly on August 14, 2016, 10:01:10 pmThe best outdoor joint protection solution is what our NZ power supply companies used to use:First layer of grease filled Denso tape then topped with self amalgamating tape.I've opened decades old joints to find the conductors looking like the day the joint was made with zero sign of water ingress.I always take a mo to chat with linesmen and top up with a little more SA tape.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: August 15, 2016, 02:20:33 am
content: Quote from: GEuser on August 15, 2016, 12:49:46 amLeft field has been heard from

author: jopie
author_rank: Contributor
timestamp: August 15, 2016, 06:02:00 am
content: I have had some good experience with self-amalgamating tape when using outdoors. When applied, it fuses into a waterproof shield and it is UV-resistant. No problem using SO-239 connectors when used with this tape. Juist don't buy yourself the cheapest connector but go for good quality ones.