(meteorobs) Coax connection to BNC - what is right?

[Paul Goelz]

At 10:19 AM 5/20/2015, you wrote:

>Ok. have a right angle solder less BNC connector. Now, how do you 
>connect coax to it?
>
>
>reason - hooking to my antenna for radio meteors...:
>
>
>I know the center copper piece goes around the screw and is tightened.
>
>
>NOW:
>
>
>1)   Does the sheath attach to the arm that gets crimped?
>
>
>2 ) Do you cut the sheath away and just leave the coax and center piece?

Not sure I follow.  I'm not familiar with any solderless BNC 
connectors that have screw terminals.  In any case, the center 
conductor of the coax connects to the center pin of the radio's BNC 
connector.  The shield connects to the shell of the radio's 
BNC.  Coax normally only has two parts.... the center conductor and 
the shield.

Is this perhaps double shielded coax?  In that case, the inner shield 
may or may not be electrically connected to the outer shield, but I 
would consider the inner shield as "the" shield.  Do you know the 
coax type number?

You MUST connect both the center conductor and the shield.  If you do 
not connect the shield, the entire length of coax and anything also 
connected to it will just be a simple long wire "antenna" and 
probably not very effective.

You should get infinite resistance between coax center and shield 
with the antenna disconnected.  If not, you have a short 
somewhere.  That should also be true with the antenna connected but 
there are some antenna designs that have DC continuity from center to 
shield.  For example, any intervening transformer will have a low 
resistance between center and shield.

And a couple of terms..... 0 ohms is LOW resistance / shorted.  Open 
circuit is infinite resistance (ie., very high).  Is that what you meant?

Make sense?  If not, we need some more details.

Paul


Paul Goelz
Rochester Hills, MI
pgoelz at comcast.net
www.pgoelz.com