On 12/4/22 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?
  If torqued to 5-8 in-lb they shouldn't be loosening.  That's definitely 
more than finger tight, and pretty "snug" with a small open end wrench. 
The usual "ignition wrench" is about 4" long, so 1-1.5 lbs force on it. 
If you've got a small scale (e.g. kitchen) you can feel what 1 pound of 
push is like, and go from there. Or, if you can buy or borrow a real SMA 
torque wrench, you'll get the feel.
 They're about $150 for the real thing that comes calibrated from the 
factory.  About $50 from some random 6 letter company on Amazon.  There 
is a spring assembly inside them that needs to be periodically 
calibrated ( I don't know how fast these things go "out of cal" - it's a 
spring, it's way less than the spring's ultimate yield, so it should 
last forever)
 I suppose one could "stake" it with some removable polymer (nail polish, 
model airplane glue, glyptal) after tightening. A tiny dab on the edge 
will keep it from loosening and is still breakable with a wrench to 
remove it.
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
 
 |