Mag Mount lesson
 

Maybe some people can take something away from my unfortunate experience.


Wanting something to use on occasions where I don't want to install my
Bugcatcher, but would still like to do a little HF, I went to a Hamfest
Sunday and picked up a 20 meter Hamstick and a big honkin' mag mount for it.

Installation was pretty straightforward. I installed it in the parking
lot, tuned it up and set off home. Most of the way it was just FB. It
wasn't the bugcatcher, but I knew that going in.

Traveling over the Alleghenies, there is an area where there are some
fair sized gusts of wind. I hit this on the downhill side of the last
mountain rage heading into the valley near home.

I was traveling about 65 mph, when a gust of wind came along, ripped the
antenna and mount off the roof. The exit for the coax is on the back
door. As the antenna and mount traveled backwards, the cable held it in
position, so it swung in an arc and hit the rear window of my Vitara.

Ouch.

The glass of rear windows is different than that of front windows. It is
designed to granulate instead of hold together. It looks pretty cool in
fact. The sudden opacity of the glass radiating from the spot of impact,
then everything disintegrating and falling into the back of the vehicle.

But the visual interest does not make up for the fact that now I have an
expensive mess to clean up.

NO more frickin' magnets! PTUI!


- 73 de Mike N3LI -

Mag Mount lesson
 

As bad as that experience was, it could have been worse. If the coax had
come loose, it could have broken the windshield of or caused other
damage to a following car.

I had a 5/8 wave 2 meter whip come loose once. It stayed connected and
bounced along behind the car for a while -- luckily no damage except to
the whip. I've used only 1/4 wave 2 meter whips since.

Roy Lewallen

Michael Coslo wrote:
Maybe some people can take something away from my unfortunate experience.


Wanting something to use on occasions where I don't want to install my
Bugcatcher, but would still like to do a little HF, I went to a Hamfest
Sunday and picked up a 20 meter Hamstick and a big honkin' mag mount for
it.

Installation was pretty straightforward. I installed it in the parking
lot, tuned it up and set off home. Most of the way it was just FB. It
wasn't the bugcatcher, but I knew that going in.

Traveling over the Alleghenies, there is an area where there are some
fair sized gusts of wind. I hit this on the downhill side of the last
mountain rage heading into the valley near home.

I was traveling about 65 mph, when a gust of wind came along, ripped the
antenna and mount off the roof. The exit for the coax is on the back
door. As the antenna and mount traveled backwards, the cable held it in
position, so it swung in an arc and hit the rear window of my Vitara.

Ouch.

The glass of rear windows is different than that of front windows. It is
designed to granulate instead of hold together. It looks pretty cool in
fact. The sudden opacity of the glass radiating from the spot of impact,
then everything disintegrating and falling into the back of the vehicle.

But the visual interest does not make up for the fact that now I have an
expensive mess to clean up.

NO more frickin' magnets! PTUI!


- 73 de Mike N3LI -

Mag Mount lesson
 

Michael Coslo wrote:
Maybe some people can take something away from my unfortunate experience.


Wanting something to use on occasions where I don't want to install my
Bugcatcher, but would still like to do a little HF, I went to a Hamfest
Sunday and picked up a 20 meter Hamstick and a big honkin' mag mount for
it.

Installation was pretty straightforward. I installed it in the parking
lot, tuned it up and set off home. Most of the way it was just FB. It
wasn't the bugcatcher, but I knew that going in.

Traveling over the Alleghenies, there is an area where there are some
fair sized gusts of wind. I hit this on the downhill side of the last
mountain rage heading into the valley near home.

I was traveling about 65 mph, when a gust of wind came along, ripped the
antenna and mount off the roof. The exit for the coax is on the back
door. As the antenna and mount traveled backwards, the cable held it in
position, so it swung in an arc and hit the rear window of my Vitara.

Ouch.

The glass of rear windows is different than that of front windows. It is
designed to granulate instead of hold together. It looks pretty cool in
fact. The sudden opacity of the glass radiating from the spot of impact,
then everything disintegrating and falling into the back of the vehicle.

But the visual interest does not make up for the fact that now I have an
expensive mess to clean up.

NO more frickin' magnets! PTUI!


- 73 de Mike N3LI -

Hello, and I'll also state from experience that mag-mounted whip
antennas are not for vehicles in motion at any speed. Sincerely and 73s
from N4GGO,

Mag Mount lesson
 

On Jun 8, 10:48*am, Michael Coslo wrote:


I was traveling about 65 mph, when a gust of wind came along, ripped the
antenna and mount off the roof. The exit for the coax is on the back
door. As the antenna and mount traveled backwards, the cable held it in
position, so it swung in an arc and hit the rear window of my Vitara.

Ouch.

The glass of rear windows is different than that of front windows. It is
designed to granulate instead of hold together. It looks pretty cool in
fact. The sudden opacity of the glass radiating from the spot of impact,
then everything disintegrating and falling into the back of the vehicle.

But the visual interest does not make up for the fact that now I have an
expensive mess to clean up.

NO more frickin' magnets! PTUI!

* * * * - 73 de Mike N3LI -

Your experience is exactly why I've been afraid to mount an
antenna on my newest car. It never fails.. @#$% happens!!!
And when it does, it's often ugly.
I've also been afraid of mag mounts even though that is a
possible way to get on HF from a small car.
But they can get knocked off, and I'm also afraid that I
could cause sheet metal damage just pulling some of
the larger ones off the car.
So anyway, I've had that car over two years now, and I
still don't have a radio in it.
That is very unusual for me, but I hate dents, scratches, etc
on a car that doesn't have any yet..
I still have two radioactive trucks if I really feel the need to
talk. :/

Mag Mount lesson
 

In message , J. B. Wood
writes

Hello, and I'll also state from experience that mag-mounted whip
antennas are not for vehicles in motion at any speed. Sincerely and
73s from N4GGO,

A whippy stainless steel 'base loaded' 2m 5/8 on a 7" magmount is almost
impossible to remove. It's probably good for 200 or 300 mph at least. I
believe 'like **** to a blanket' is appropriate.
--
Ian

Mag Mount lesson
 

Mag Mount lesson
 

On Jun 8, 3:41*pm, dave wrote:


Have a receiver type trailer hitch installed.

Nothing to attach one to unless you installed
some kind of frame underneath the rear of the car.
There is nothing underneath except the bottom
of the trunk floor if I remember right.
But even if I could mount a hitch mount, I'm not
sure how happy I would be with it.
Generally, that's about as bad a place to mount
an antenna as you can find.
The one method I might consider would be a trunk
lip mount. And even that makes me paranoid as
I'm worried the stress of the antenna whipping
back and forth will warp the trunk lid after a
period of time. The metal is pretty thin on that car.
"Toyota Corolla".
I've just been taking my radio with me, and using
the antenna's I have at the site.
But now even more great news.. :( My 706mk2g
has been acting squirrely. 440 went out on it,
and I think the band switching diodes or transisters
blew up. I used it a while with no 440 and was
ok, but now it's acting weird, locking up, etc..
So it's sick and is gonna have to visit the radio doc.
I don't think I want to mess with it. I've fixed most
my own rigs in the past, but I don't think I want to
mess with that thing. So I'm gonna send it off.
I need to find me another HF mobile backup rig...
The 706 is the only 12v HF rig I've got right now.
Well.. I do have an old IC 730, but the display
board is out.

Mag Mount lesson
 

wrote:
On Jun 8, 3:41 pm, dave wrote:

Have a receiver type trailer hitch installed.

Nothing to attach one to unless you installed
some kind of frame underneath the rear of the car.
There is nothing underneath except the bottom
of the trunk floor if I remember right.

You can get a "light duty" receiver for almost any car (used to hold
bike racks and the like). I was going to go that route for my BMW 325,
but after looking at the design, I built my own.. A piece of 1x1 square
tubing bolted to the bottom of the spare tire well (this is what the
trailer hitch bolted to). Drilled two 3/8" holes in the bottom of the
well to bolt it on.

Then, the antenna mounts on bracket made of the nesting square tubing
(e.g. 3/4") and there's a 1/4" pin that holds it in. I just slid the
3/4" tubing in and drilled both together (guaranteed registration of the
holes!)..

The 3/4" tube (which is roughly horizontal) is joined to another
vertical piece of tubing, to which a SGC tuner and the 9-10 ft whip is
attached.

http://home.earthlink.net/~w6rmk/mobile.htm

Why not use the trailer hitch? Because when I called around to buy one,
nobody local had one in stock, and I was motivated to "get it done today"..

But even if I could mount a hitch mount, I'm not
sure how happy I would be with it.
Generally, that's about as bad a place to mount
an antenna as you can find.
The one method I might consider would be a trunk
lip mount. And even that makes me paranoid as
I'm worried the stress of the antenna whipping
back and forth will warp the trunk lid after a
period of time. The metal is pretty thin on that car.
"Toyota Corolla".

I use a Comet trunklip mount for the VHF/UHF whip. If you adjust the
angle right, it clears the roof of the car when you open the trunk.
CP-5NMO

http://www.cometantenna.com/products...D=9&childID=14



I've just been taking my radio with me, and using
the antenna's I have at the site.
B

Mag Mount lesson
 

On Jun 8, 4:28*pm, wrote:
On Jun 8, 3:41*pm, dave wrote:



Have a receiver type trailer hitch installed.

Nothing to attach one to unless you installed
some kind of frame underneath the rear of the car.
There is nothing underneath except the bottom
of the trunk floor if I remember right.
But even if I could mount a hitch mount, I'm not
sure how happy I would be with it.
Generally, that's about as bad a place to mount
an antenna as you can find.
The one method I might consider would be a trunk
lip mount. And even that makes me paranoid as
I'm worried the stress of the antenna whipping
back and forth will warp the trunk lid after a
period of time. The metal is pretty thin on that car.
"Toyota Corolla".
I've just been taking my radio with me, and using
the antenna's I have at the site.
But now even more great news.. *:( *My 706mk2g
has been acting squirrely. 440 went out on it,
and I think the band switching diodes or transisters
blew up. *I used it a while with no 440 and was
ok, but now it's acting weird, locking up, etc..
So it's sick and is gonna have to visit the radio doc.
I don't think I want to mess with it. I've fixed most
my own rigs in the past, but I don't think I want to
mess with that thing. So I'm gonna send it off.
I need to find me another HF mobile backup rig...
The 706 is the only 12v HF rig I've got right now.
Well.. I do have an old IC 730, but the display
board is out.


Is this common 706 problem? i have heard it before

Mag Mount lesson
 

Michael Coslo wrote:
Maybe some people can take something away from my unfortunate experience.
snip
- 73 de Mike N3LI -


I have had a couple negative experiences with single magnets, and one
with a 6 meter halo on a triple magnet. I would say the triple or quad
with a hamstick is practically impossible to knock off, however. At
least at any speed less than 30 over the interstate limit including
normal wind gusts. Or so I've heard.

One other thing you need to consider about magnet mounts is that a layer
of water will end up underneath the magnet due to imperfections in it
and the roof. You _will_ damage the paint if you leave it on for more
than a few days at a time. You _will_ damage your paint if you put it
on and remove it regularly to get rid of the water. It's a Catch-22.

tom
K0TAR