[TowerTalk] Reliability (or not) of SMA connectors

[Richard (Rick) Karlquist]

First: hand tight is never reliable in my experience.

Second:  you can't just tighten them with a open end wrench,
because too much torque can damage them.

Third:  Connecting two modules together using a double
male SMA makes the connection subject to being loosened if
the modules are handled.  Ditto for using semi-rigid
coax to connect them.  90 degree double males are even
more dangerous.  It will make it even more likely that
handling the modules will loosen the SMA's.  SMA to SMA
attenuators are another problem.

For best results, use only very flexible cables to make
connections, and make the cables long enough so that
there is always some slack in the cables.

They can work well for interconnecting modules that are
bolted down.  The problems start if the modules are
just "floating".

They are definitely not fool-proof.

Rick N6RK


On 12/4/2022 6:05 AM, Pete Smith N4ZR wrote:
> I'm not sure if this is the right place or not, but thought I'd ask 
> because this is at least a feedline question.
> 
> I have a number of SMA connectors in areas of my station like my RBN SDR 
> and my N1MM Spectrum Display.  It seems like every few weeks I start 
> running into problems, and have to go through and retighten them to get 
> rid of intermittent signal losses.  Is there anything that can be done 
> to secure them better?
>