On Mon, 18 May 2009 11:09:13 -0700, "Al Lorona"
wrote:

There seems to be no
urgency on the part of the CHP to refer to a vehicle code to enforce the
height.

Depending on structural integrity, that would be self-enforcing,
wouldn't it?

From http://en.wikipedia.org/wiki/Interst...hway_standards

Vertical clearance. Minimum vertical clearance under overhead
structures (including over the paved shoulders) of 16 ft (4.9 m) in
rural areas and 14 ft (4.3 m) in urban areas, with allowance for extra
layers of pavement. Through urban areas at least one routing should
have 16 ft (4.9 m) clearances. Sign supports and pedestrian overpasses
must be at least 17 ft (5.1 m) above the road, except on urban routes
with lesser clearance, where they should be at least 1 ft (0.3 m)
higher than other objects. Vertical clearance on through truss bridges
is to be at least 17 ft (5.1 m).

73's
Richard Clark, KB7QHC

Al Lorona wrote:

Thanks, Dave, for the exact reference sites. They were helpful. And thanks
to all the others for their replies.

I think it's clear that finding one number-- one right answer-- is
difficult. I just called the California Highway Patrol office in Altadena
and found that there really is no right answer. The guy at the front desk
said that the "consensus" in the office was 14 feet. And of course he was
speaking only for California. He said that there's no separate regulation
for antennas, only the number for total vehicle height. There seems to be no
urgency on the part of the CHP to refer to a vehicle code to enforce the
height.

As you saw, the replies to my post ranged from 12.5 to 14 feet. It surprises
me that the standard deviation implied by this spread is that large.

All in all, this has been very surprising.

Thinking about it some more, perhaps the limiting factor becomes not bridges
and overpasses, but fast food drive-thrus and gas station roofs.


The very clear thing, at least here in Minnesota, is if you break it,
you bought it. A rig towing a large piece of equipment was a bit too
tall and struck an overpass on one of the I94 bypasses. Their insurance
company bought a nice new 4 lane overpass that traversed the 6 lane
bypass. Not cheap.

tom
K0TAR

On Mon, 18 May 2009 11:09:13 -0700, Al Lorona wrote:

Thinking about it some more, perhaps the limiting factor becomes not
bridges and overpasses, but fast food drive-thrus and gas station
roofs.

I can still remember my dad (the first W3DHJ) telling the story of the
night back in 1952 when he had to buy seven 8' fluorescent lamps at a
gas station somewhere outside Pasco, Wash.


The maximum height for _my_ mobile antennas is 7' 1". My garage
door is at 7' 2" and I know someday I'll blissfully drive into
the garage someday with the 6M Halo mounted.

Jonesy W3DHJ
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
* Killfiling google & XXXXbanter.com: jonz.net/ng.htm

On May 18, 9:18*pm, Allodoxaphobia wrote:
On Mon, 18 May 2009 11:09:13 -0700, Al Lorona wrote:
Thinking about it some more, perhaps the limiting factor becomes not
bridges and overpasses, but fast food drive-thrus and gas station
roofs.

I can still remember my dad (the first W3DHJ) telling the story of the
night back in 1952 when he had to buy seven 8' fluorescent lamps at a
gas station somewhere outside Pasco, Wash.

The maximum height for _my_ mobile antennas is 7' 1". *My garage
door is at 7' 2" and I know someday I'll blissfully drive into
the garage someday with the 6M Halo mounted.

Jonesy W3DHJ
--
* Marvin L Jones * *| jonz * * * * *| W3DHJ *| linux
* *38.24N *104.55W *| *@ config.com | Jonesy | *OS/2
* * * Killfiling google & XXXXbanter.com: jonz.net/ng.htm

I did that atanold abandoned gas station one night when I oulled under
the canopy to get out of a storm. It didnt look like I was the first
to do it.

Jimmie

wrote in message
...
Al Lorona wrote:

"Dave Platt" wrote in message
...
In article ,

Take a look at

http://wwwcf.fhwa.dot.gov/legsregs/d...pg/0625sup.htm


Thanks, Dave, for the exact reference sites. They were helpful. And
thanks
to all the others for their replies.

I think it's clear that finding one number-- one right answer-- is
difficult. I just called the California Highway Patrol office in
Altadena
and found that there really is no right answer. The guy at the front
desk
said that the "consensus" in the office was 14 feet. And of course he
was
speaking only for California. He said that there's no separate
regulation
for antennas, only the number for total vehicle height. There seems to
be no
urgency on the part of the CHP to refer to a vehicle code to enforce the
height.

..

Don't even think about going to Vegas with an antenna much over 8 feet
tall unless you plan on parking in the back 40 with the RV's.

I drive my Dodge Caravan to Las Vegas and my little MFJ dual-band mag mount
hits the overhead in some parking structures. I sometimes remember to
unscrew the element on the way in.

Fast food joints often have a pipe hanging on chains as a noisy warning that
_something_ won't clear their building.

Sal M. Onella wrote:
Fast food joints often have a pipe hanging on chains as a noisy warning that
_something_ won't clear their building.

OTOH, they often have a low awning over the drive
through window with no warning of the low height.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

On May 18, 1:28*pm, Cecil Moore wrote:


For one of the CA 75m shootouts that I prepared for,
I had a white PVC pipe extending up about 9 feet from
the tool box on my pickup.

On the truck with the highest antenna mount, "64 inches
from the ground", my 11 ft tall antenna is 16.3 inches at
the tip. In the parked mode with the extra 3 ft mast extension,
it's at 19.3 inches. And the loading coil is 8 ft above the
base.
The other truck has a lower mount which is maybe 1.5-2 ft lower
at the base of the antenna. It's mount is on top of the utility
bed side tops which are tool boxes, and fairly wide.
The first truck has the mount up on the cab just a few inches
below the roof.
But.. I've been trying to sell that truck..
But I could place the mount at the same place on the other
one if I really wanted to. I might once the other one is gone.
One thing.. my antenna sways back a bit at speed, so I
can clear objects lower than the actual antenna height if I'm
going fast enough. The most seen problem is whacking
trees in residential areas.. I have the mount on the drivers
side, and I still have to dodge some of the trees. Some
I can't dodge, so I hear the "whack".. But the top 5 ft is
thin flexible whip, so no big deal.
I don't think I've ever noticed hitting a bridge or overpass.
I've still been too chicken to try to mount an antenna on
my Corolla... Not too many ways to go, and most all
of them will end up buggering up the car before it's over
with.

On May 18, 11:09*am, "Al Lorona" wrote:
"Dave Platt" wrote in message

...

In article ,

Take a look at

*http://wwwcf.fhwa.dot.gov/legsregs/d...pg/0625sup.htm

Thanks, Dave, for the exact reference sites. They were helpful. And thanks
to all the others for their replies.

I think it's clear that finding one number-- one right answer-- is
difficult. I just called the California Highway Patrol office in Altadena
and found that there really is no right answer. The guy at the front desk
said that the "consensus" in the office was 14 feet. And of course he was
speaking only for California. He said that there's no separate regulation
for antennas, only the number for total vehicle height. There seems to be no
urgency on the part of the CHP to refer to a vehicle code to enforce the
height.

As you saw, the replies to my post ranged from 12.5 to 14 feet. It surprises
me that the standard deviation implied by this spread is that large.

All in all, this has been very surprising.

Thinking about it some more, perhaps the limiting factor becomes not bridges
and overpasses, but fast food drive-thrus and gas station roofs.

very much true, Al. Bent more than one antenna bracket forgetting
about the 9 foot stalk poking up.

On May 19, 6:51*am, wrote:
On May 18, 11:09*am, "Al Lorona" wrote:



"Dave Platt" wrote in message

...

In article ,

Take a look at

*http://wwwcf.fhwa.dot.gov/legsregs/d...pg/0625sup.htm

Thanks, Dave, for the exact reference sites. They were helpful. And thanks
to all the others for their replies.

I think it's clear that finding one number-- one right answer-- is
difficult. I just called the California Highway Patrol office in Altadena
and found that there really is no right answer. The guy at the front desk
said that the "consensus" in the office was 14 feet. And of course he was
speaking only for California. He said that there's no separate regulation
for antennas, only the number for total vehicle height. There seems to be no
urgency on the part of the CHP to refer to a vehicle code to enforce the
height.

As you saw, the replies to my post ranged from 12.5 to 14 feet. It surprises
me that the standard deviation implied by this spread is that large.

All in all, this has been very surprising.

Thinking about it some more, perhaps the limiting factor becomes not bridges
and overpasses, but fast food drive-thrus and gas station roofs.

very much true, Al. *Bent more than one antenna bracket forgetting
about the 9 foot stalk poking up.

One other thing to think about, what with all the quotes from the
federal standards..
The states don't have to follow the standards for ALL roads. A state
can say "on federal highways the limit is X, but on all other roads
it's Y (where YX)". For that matter, in some states, local
municipalities can set different limits. This makes for nice revenue
enhancement opportunities. "Well son, here in X, the limit for semi
trucks is 15 feet, but for funny looking antennas on cars with funny
license plates, it's 8 feet. Please step out of the car and keep your
hands in plain sight."

A friend ran into this distinction (except for it being width) in, I
think, Nebraska (somewhere in the great plains)... Federal standards
are 108 inches, local rule is 96.. and there are difference in whether
you count rear view mirrors. If only he had stayed on the interstate.

All of which means it is a good idea to have a pulley system to both guy a
long antenna and quickly retract it like you see on mil vehicles. I have
had to go out and remove an 800 spike when entering parking garages, so it
is a good idea to make those mounts easily accessable. I like to put them
where I can reach them from the driver or passenger door. KNOW YOUR
CLEARANCE! I often use an old expendable CB whip for HF reception and go
out and swap antennas when I want to get on the air.