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Coax L adapter causing issues

May 28, 2023
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I recently ordered and installed an L shaped coax adapter on the back of my radio due to the way the coax was being kinked as it entered into the radio in my truck’s dash. I was trying to alleviate the kink. The back of the radio has the cable pretty much jammed into the dash, and unless I want to cut the dash, I don’t see a fix except for using this L adapter. Anyway, I thought it was all good, and it was for a couple of days. I mostly just listen and have not had a lot of reason to talk. Well today I tried to talk and I noticed as soon as I did that the volume of the radio had dropped to nothing after I released the PTT button. It was like I had turned the RF gain all the way down. I could still hear static and voices, but very muted. It would remain that way for awhile and then slowly come back.

After messing with it for a good while, driving around listening to the static and distant signals in low volume, I got home and decided to hook up the SWR meter and see what it showed. With the meter connected, when I pressed the PTT button I got no needle movement whatsoever. Then every now and again it would give me a reading. Change channels and the reading is back to zero again and the radio is back to low volume. So finally I removed the adapter and connected the coax straight to the radio and then the problem was solved. I reinstalled the adapter and the problem came right back, so I concluded that the adapter was the issue. My question is why? Could it simply be defective or is there something else that I am misunderstanding about how it works?

Also since I had the meter out I decided to see what it would do for field strength testing. This is a Surecom SW-114 and it was suggested that it might not even respond. I was alone and in a wide open field (setting SWR again after moving my antenna back a foot) so all I could do was hold it in my hand out in front of the windshield while keying the mic and speaking into it. I saw the needle move just a bit, but it did actually respond, although just barely. I don’t know if this is indicative that the meter is lousy for that or if I utterly did the test wrong. I think ideally it should be out in front of the vehicle a ways off and there should be two people, one to read it and one to key the mic. This is an experimental learning process for me so I was just interested to see it do anything at all.
 
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Those 90deg adapters can and will get loose. Cars go over bumps and stuff. I have one on the back of my radio because just like you, there is no room since the vent tube is right behind in the dash. Get some channel locks and give it a little umph. Don’t King Kong it. Just a little smidge. Check it from time to time or when you think something is off.
 
if you have to crank an adapter on with pliers something is wrong, there is absolutely no need to do that. as far as uhf elbow connectors go, i have been there and done that. and i can tell you i have experienced your issue and its due to using a cheap chinese made $5 connector. the cheap piece of crap connectors always cause problems,. they short when you tighten them to much, they arc inside due to poor construction and materials etc. they are complete garbage. you need to step up and buy a quality connector from amphenol, pasternak, or other high end rf connector company. i have never had an issue ever using high end rf connectors and adapters. buy quality once and be done. $20, who cares. do it right. Test: loosen the elbow a bit and jiggle/move it around, i bet you will hear the receive cut in and out, guaranteed.
 
Yeah it was tight, as tight as I could make it with bare hands only. And the radio is not mounted solid yet so when I picked it up I did hear reception come and go some. The connector was $6 on Amazon, so that’s it, that was the problem right there. I’m gonna return it and look for something better. Thanks.
 
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Yeah it was tight, as tight as I could make it with bare hands only. And the radio is not mounted solid yet so when I picked it up I did hear reception come and go some. The connector was $6 on Amazon, so that’s it, that was the problem right there. I’m gonna return it and look for something better. Thanks.
bam! i knew it, like i said i have been there. toss that crap and buy s quality uhf elbow. one of these will be a solid choice.
 
Thanks for the links, that really helps. Is there any real difference between any of those? Two of them are about $8 and one is over $20. They all look the same. One says it can handle high power but it’s one of the lower priced ones.
 
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Thanks for the links, that really helps. Is there any real difference between any of those? Two of them are about $8 and one is over $20. They all look the same. One says it can handle high power but it’s one of the lower priced ones.
all solid choices. amphenol is always expensive but they are one of the best. they supply and are used by most of the the commercial broadcast industry. the high power one has a teflon center insulator and the other one has a delrin center insulator. i only use amphenol. but for you, connected to just a cb radio i would choose one of the two lower priced ones. both are fine. choice is yours
 
all solid choices. amphenol is always expensive but they are one of the best. they supply and are used by most of the the commercial broadcast industry. the high power one has a teflon center insulator and the other one has a delrin center insulator. i only use amphenol. but for you, connected to just a cb radio i would choose one of the two lower priced ones. both are fine. choice is yours
all solid choices. amphenol is always expensive but they are one of the best. they supply and are used by most of the the commercial broadcast industry. the high power one has a teflon center insulator and the other one has a delrin center insulator. i only use amphenol. but for you, connected to just a cb radio i would choose one of the two lower priced ones. both are fine. choice is yours
Thanks again. I just ordered the RFU-532.
 
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Check your coax also near where it was kinked. May not be likely if it was not kinked for long, but if it was there could be some damage within that may or may not manifest itself with the symptoms you describe once straightened. I had it happen once in the mobile. Had to cut it back a bit an reinstall the 259.
 
Check your coax also near where it was kinked. May not be likely if it was not kinked for long, but if it was there could be some damage within that may or may not manifest itself with the symptoms you describe once straightened. I had it happen once in the mobile. Had to cut it back a bit an reinstall the 259.
It wasn’t kinked for long. I had just installed it last week and didn’t like how the coax was being bent to connect to the radio so I ordered that part and put it on. That’s why I don’t yet have the radio permanently fastened in place so I don’t bind the coax too badly until I get another elbow connector.
 
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It wasn’t kinked for long. I had just installed it last week and didn’t like how the coax was being bent to connect to the radio so I ordered that part and put it on. That’s why I don’t yet have the radio permanently fastened in place so I don’t bind the coax too badly until I get another elbow connector.
Just as groundwire said, you just can't go cheap with connectors. It's just not worth holding out only to toast your radio over a failing connector.

Coax and antenna is the other half of your system, your radio can only perform as best as the components getting the signal out. No maybe you can't pocket top tier stuff but at least steer clear of the bottom shelf stuff.

We've all learned that lesson my friend, believe me in my early days of the hobby I bought a lot of junk not knowing any better.
 

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