ant coax routing question

[RB]

Putting a "shortie" marine VHF ant on the boat. This ant is the one with a
loading/matching coil at the bottom of the whip.

The coax comes down from the center of the coil. The base of the coil has a
threaded female fitting same thread/dia as the male counterpart of the lay
down mount. The lay down mount has holes in it to accommodate the coax in
its journey to the radio.

Question is how the heck do I screw the ant onto the mount without the coax
cord getting twisted to the point of damage? Is the idea that the coax will
roll (twist) enough as I'm screwing the ant onto the base that it won't
damage something?

I know some of you have been there/done this, so tell me the way out of the
problem.

 

[Peter Bennett]

Putting a "shortie" marine VHF ant on the boat. This ant is the one with a
loading/matching coil at the bottom of the whip.

The coax comes down from the center of the coil. The base of the coil has a
threaded female fitting same thread/dia as the male counterpart of the lay
down mount. The lay down mount has holes in it to accommodate the coax in
its journey to the radio.

Question is how the heck do I screw the ant onto the mount without the coax
cord getting twisted to the point of damage?

_very_ carefully!

Is the idea that the coax will
roll (twist) enough as I'm screwing the ant onto the base that it won't
damage something?

I know some of you have been there/done this, so tell me the way out of the
problem.

In theory, the hole in the mount should be large enough that the coax
will easily rotate in the mount (but not relative to the antenna) as
you screw the mount into the base of the antenna.

Unfortunately, theories such as this are often wrong. My
brother-in-law had a shop install a new antenna and mount of this type
on his Whaler - they managed to twist the coax enough that the center
conductor and shield shorted, but the cable remained attached to the
antenna, so the fault wasn't obvious. I found the problem after he
complained of poor reception - he could only receive if the connector
on the radio was left loose, so the shield didn't make contact.


--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

 

[Larry]

Question is how the heck do I screw the ant onto the mount without the
coax cord getting twisted to the point of damage? Is the idea that the
coax will roll (twist) enough as I'm screwing the ant onto the base
that it won't damage something?

Solution....Take back Shakespeare's piece of crap with the unrepairable
coax in it and get the Metz 1/2 wave (no ground necessary) that has a
proper coax connector on the bottom of it so it can be REPAIRED.....

http://www.metzcommunication.com/manta6.htm
warrantied for life....

USCG uses Metz for a reason....(c;

When you swap boats, don't forget to take your Metz antenna with you for
your new boat. Let the new guy buy his OWN Metz....(c;

Problem solved....next problem.

 

[Alec]

Peter is correct, it should twist as you screw in. But to help smear a bit
of washing up liquid on the coax outer to reduce friction and apply about 2
turns the wrong way before starting to screwin. It worked for me.

Alec

 

[Gary Schafer]

How about removing the mount and screw it onto the antenna and then remount
it. That way there would be no twisting of the coax.

Leanne

Wouldn't that be the same as changing a light bulb by having one guy
stand on the ladder and two other guys rotate the ladder? :>)

Regards
Gary

 

[Lynn Coffelt]

about with
How about removing the mount and screw it onto the antenna and then remount
it. That way there would be no twisting of the coax.

Leanne

Of course! Why didn't the "old heads" tell you this first?
Old Chief Lynn