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How to install a ballmount antenna? experts?

Posted: Wed Nov 15, 2006 4:03 pm
by Brentd2183
How do i install a ball mount antenna, its been a long time since ive messed with one and im trying to remember the order of the parts for how they get installed. Its the big mount with the plastic disk on the outside and the inside i have metal plate and the all the nuts and screws.
Just run me through it again, any tips would be great.

Posted: Wed Nov 15, 2006 5:50 pm
by kb0nly
That ball mount didn't come with any instruction whatsoever?

Generally its the ball mount base, the plastic piece, the vehicle body, then the metal piece, than the nuts on the screws.

Posted: Thu Nov 16, 2006 2:27 pm
by techie
Methinks you replied to the wrong topic :-)..

and you really should give Z! credit for the duct tape quote..

Posted: Thu Nov 16, 2006 4:03 pm
by kb0nly
techie wrote:Methinks you replied to the wrong topic :-)..

and you really should give Z! credit for the duct tape quote..
Yeah i just noticed that, the post for the other thread went here, and the one for here went over there. I don't know how the heck that happened because i posted to this one first.

Anyway, all fixed.

Who is Z??

Posted: Thu Nov 16, 2006 4:11 pm
by k2hz
Not sure if what you have is the traditional ball mount but, if so, there should be the following parts:

The plastic base
A rubber gasket
The metal backing plate
3 screws, nuts and lockwashers.

Drill the large center clearance hole first then use the plastic base as a template for the 3 screw holes.

The metal backing plate goes inside the vehicle and the rubber gasket goes outside, under the plastic base.

If possible, clean the contact area on the vehicle for the backing plate to make a good ground contact.

It has been a few years since I installed one and I can't find an instruction sheet but I think this should cover what you need.

Posted: Thu Nov 16, 2006 7:48 pm
by Brentd2183
Yup that the order, only issue was last time is that the large nut on the back of the ball that gets tighten down against the body of the car so its grounded, well its all metal right on through to where the coax screws onto the top and i had a dead short, its not like its insulated from the outside, i had to make a plastic washer between the car and the big nut then all the reading were great, but something just seems very wrong about that. Tell me im missing something

Posted: Fri Nov 17, 2006 5:00 am
by Jim202
You need to make the center hole large enough so that
the big backing nut on the inside can fit through the hole
in the vehicle body. The nut needs to be isolated from
the metal body of the vehicle. It has been a long time
since I installed one of these, but the hole is rather large.

With you placing an insulating washer under the nut,
your changing the impedance match at that piont. It is
also hard to get the nut tight enough to prevent the ball
and spring from turning on the plastic mounting plate with
your added washer.

Jim


Brentd2183 wrote:Yup that the order, only issue was last time is that the large nut on the back of the ball that gets tighten down against the body of the car so its grounded, well its all metal right on through to where the coax screws onto the top and i had a dead short, its not like its insulated from the outside, i had to make a plastic washer between the car and the big nut then all the reading were great, but something just seems very wrong about that. Tell me im missing something

Posted: Fri Nov 17, 2006 9:56 am
by Brentd2183
Ok so that giant nut DOES NOT get tighten against the car's body, it goes through the hole of the metal backing plate, and then thru the hole in the car's body, so what does it tighten against? What is it doing? Im sure if i was looking at it right now i could figure that out but im stuck in the computer lab at school. I did get an SWR of 1.3 but i'll check it out today.

Posted: Fri Nov 17, 2006 10:34 am
by k2hz
The clearance hole in the car body needs to be the same size as the hole in the backing plate. The "giant nut" is what secures the screw that holds the ball to the plastic base and is the point of connection for the coax center. The coax shield connects to a screw on the backing plate.

You need a full size clearance hole for that nut so you do not short out the antenna to the car body.

Posted: Sat Nov 18, 2006 1:06 am
by techie
kb0nly wrote:
techie wrote:Methinks you replied to the wrong topic :-)..

and you really should give Z! credit for the duct tape quote..
Yeah i just noticed that, the post for the other thread went here, and the one for here went over there. I don't know how the heck that happened because i posted to this one first.

Anyway, all fixed.

Who is Z??

Carl Zwanzig.. (aka Z! [pronounced zee-bang] ) is the person normally credited with coining the phrase "Duct tape is like the force. It has a light side, and a dark side, and it holds the universe together."

Posted: Sun Nov 19, 2006 7:19 am
by RadioSouth
Pretty much what they said. In summary, the (3) smaller bolts are the only bolts that attach the mount to the body of the car. The large center bolt has nothing to do with the mechanics of holding the mount to the car, it only alows the ball to be anchored to the mount and coax attachment.
The bolt needs to be this large as it has a bit of torque on it considering a 1 pound spring and a 8 ft. + antenna that it supports. Reminds me of the Smokey and The Bandit days when I used to make pocket cash while going to school installing these fugly things.

Posted: Sun Nov 19, 2006 10:49 am
by Brentd2183
Thanks all for the tips, it all makes sense now. I was looking at it going, something is very wrong here the thing is grounded...hmmm. I remember fixing it the last time with a plastic washer so i did it again and lo and behold swr was beautiful. Ive got the car coming over tonight and i'll make the change. Thanks all, im still yet to have a question that wasnt answered, your all the best.