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

[Dave Radomski - KTØH]

Maybe this video will help...

https://www.youtube.com/watch?v=KknYLb6EI7o



-----Original Message-----
From: meteorobs-bounces at meteorobs.org
[mailto:meteorobs-bounces at meteorobs.org] On Behalf Of Paul Goelz
Sent: Wednesday, May 20, 2015 08:58
To: Meteor science and meteor observing
Subject: Re: (meteorobs) Coax connection to BNC - what is right?

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 

_______________________________________________
meteorobs mailing list
meteorobs at meteorobs.org
http://lists.meteorobs.org/mailman/listinfo/meteorobs