HF Antenna Pickup Truck
 

Has anyone tried mounting a magnet mount hf antenna (Hamstick) on the top of
a metal toolbox, the kind that are used in the back of pickup
trucks......just curious...I realize the best place is on top of the
cab....tnx...Gary, K8BY

Gary Boyer wrote:

Has anyone tried mounting a magnet mount hf antenna (Hamstick) on the
top of a metal toolbox ...

No, but does your truck have stake pockets? There's an outfit that makes
antenna mounts that fit in the stake pockets of pickups. I got one for my
Ranger to mount a 10M Hamstick. Works pretty well and is a rugged mount. It
would probably handle something a lot bigger than the Hamstick. Can't
remember the name but they advertise in QST. I had tried a magmount in the
middle of the bed but couldn't tune the Hamstick there. I'd guess you'd
have the same problem due to the cab. Using the stake pocket mount (in the
rear-most pocket on the pasenger side) it works great.

OTOH, a friend of mine runs a screwdriver antenna mounted to the rear wall
of his toolbox in his big Dodge PU and it seems to work OK...

73.. Mark AA7TA

Has anyone tried mounting a magnet mount hf antenna (Hamstick) on the top of
a metal toolbox, the kind that are used in the back of pickup
trucks......just curious...I realize the best place is on top of the
cab....tnx...Gary, K8BY

There are two aspects to this: mechanical and electrical.

Mechanically, I'd imagine you'll be OK. A Hamstick is pretty thin,
and wouldn't have a large amount of wind-drag force on it. Assuming
that the toolbox is solidly constructed, the magmount's grip on its
roof would be sufficient to keep the antenna in place, and the drag
and torque on the toolbox lid's hinges probably wouldn't be enough to
matter. If I were you I'd arrange to snub the feed cable - clamp it
down to the frame somehow, so that if the mag-mount does pop loose you
don't find yourself dragging the antenna on the road behind the vehicle.

Electrically, there are a couple of issues. For one thing, if the
tookbox is immediately behind the cab, this arrangement might put the
Hamstick quite close to metal portions of the cab roof or uprights.
This sort of close antenna-to-body coupling tends to reduce the
antenna efficiency. Keep the antenna as far away from the metal body
as you can safely manage.

From what I've read, HF magmounts often don't have enough coupling
capacitance to give a really satisfactory grounding, even when mounted
right on the roof. It's usually desirable (and often necessary) to
run a short, fat grounding lead from the antenna base/feedpoint to a
solid grounding location on the vehicle frame. You should probably do
something like this if you do decide to mag-mount on the toolbox.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
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Aren't these tool boxes generally aluminum or stainless steel?

Gary Boyer wrote:
Has anyone tried mounting a magnet mount hf antenna (Hamstick) on the top of
a metal toolbox, the kind that are used in the back of pickup
trucks......just curious...I realize the best place is on top of the
cab....tnx...Gary, K8BY

Has anyone tried mounting a magnet mount hf antenna (Hamstick) on the top of
a metal toolbox?

Hi Gary, If your toolbox is like mine, it is Aluminum, and the mag mount
won't stick. I attached a small steel plate on the top of the box and use it
for a 2M mag mount.
For my homebrew HF mobile antenna I use a mounting system on the backside of
the box. I get good results with my bugcatcher type antenna on 80m-17m mounted
in this location. The loading coil is about 1 foot above the cab top. Since a
Hamstick is continously loaded, and may not be as efficient as a bugcatcher,
you may not have similar results, mounting at the rear of the box.


73 Gary N4AST