SMA to BNC adapter problem

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Rehab880

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I'm in Metro Atlanta and listen 800 MHz. I have a Uniden BCD436HP scanner. I was using the Uniden SMA to BNC adapter for a RS 800 MHz antenna. The adapter now appears to be stripped. When attached to the scanner, it will not tighten. It just spins around and around. I have been using the supplied SMA Rubber Duck antenna since then and there is now problem taking it off and putting it back on. Will buying a replacement adapter work or could there be a problem with the scanner not visible? I would rather spend $9 for a replacement adapter than $30 for an SMA 800 MHz antenna.

Any and all input is welcome and appreciated!

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FKimble

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SMA connections are not as robust as BNC's. Best to put the BNC adapter on and leave it on.

Frank KK4YTM
 

jaspence

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SMA to BNC

The additional length of the adapter plus the antenna can put extra stress on the original sma connector in the radio, and it can be damaged. A visual inspection of the adapter and connection on the radio with a magnifying glass should give you an idea of where the problem lies.
 

N9PBD

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Make sure it isn't the SMA connector on the radio spinning, that's a lot worse than a stripped adapter. Also, do not over tighten the adapter, like others above stated, SMA connectors are not robust. They were actually designed for a service life of around 500 mating cycles, when properly torqued. I'm not aware of any scanner user that I've come across that uses a 5/16" torque wrench set to 3–5 in·lbf (0.3 to 0.6 N·m) every time they install their antenna or adapter... :D
 

Rehab880

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Sorry, that was a typo. The adapter seems to be stripped, but there is no problem with the SMA rubber duck antenna.
 

Rred

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"The adapter seems to be stripped, but there is no problem with the SMA rubber duck antenna."
So, you need a new adapter.

The SMA connector was designed for assembling internal boards, i.e. different sections in one radio chassis. It was never intended for frequent or repeated use, just for one initial connection, and subsequent re-use during troubleshooting or modifications.

So yes, they work fine for most of us very many times--but they will strip out or cross-thread, because they are just not designed for any heavy use. Better to get another antenna, so you can leave the BNC adapter on all the time.
 
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