Maximum Antenna Height on a Vehicle
 

I have always heard that "13 feet, 6 inches" is a standard for the maximum
height of an antenna mounted on a vehicle.

However, I cannot find a credible source on the web verifying this "fact".
NHTSA, DOT, don't seem to have such an antenna regulation on their
respective web sites. I am not the most skillful user of Google, but my
searches have sure not turned up a reference to this magic number on any
authoritative site. Perhaps there is no national standard, only 50 separate
state standards, and the state with the lowest height limit would then
become the 'national standard'??

Maximum Antenna Height on a Vehicle
 

On May 17, 11:41*pm, "Al Lorona" wrote:
I have always heard that "13 feet, 6 inches" is a standard for the maximum
height of an antenna mounted on a vehicle.

However, I cannot find a credible source on the web verifying this "fact"..
NHTSA, DOT, don't seem to have such an antenna regulation on their
respective web sites. I am not the most skillful user of Google, but my
searches have sure not turned up a reference to this magic number on any
authoritative site. Perhaps there is no national standard, only 50 separate
state standards, and the state with the lowest height limit would then
become the 'national standard'??

Maybe for interstates but I have seen some overpasses that were lower
than that.

Jimmie

Maximum Antenna Height on a Vehicle
 

On May 17, 8:41*pm, "Al Lorona" wrote:
I have always heard that "13 feet, 6 inches" is a standard for the maximum
height of an antenna mounted on a vehicle.

However, I cannot find a credible source on the web verifying this "fact"..
NHTSA, DOT, don't seem to have such an antenna regulation on their
respective web sites. I am not the most skillful user of Google, but my
searches have sure not turned up a reference to this magic number on any
authoritative site. Perhaps there is no national standard, only 50 separate
state standards, and the state with the lowest height limit would then
become the 'national standard'??


It's not a rule about antennas per se, it's maximum height of
vehicle. In California, it's 14 ft (with some special exceptions).
CVC 35250. No vehicle or load shall exceed a height of 14 feet
measured from the surface upon which the vehicle stands, except that a
double-deck bus may not exceed a height of 14 feet, 3 inches. Any
vehicle or load which exceeds a height of 13 feet, 6 inches, shall
only be operated on those highways where deemed to be safe by the
owner of the vehicle or the entity operating the bus.

There's also a federal rule for interstate highways that, in effect,
says that if your vehicle is less than 14 ft high and 8 ft wide, it
will fit on all interstate highways (if there's a low bridge, you'll
have the get off and go around path marked.

CVC 35100. (a) The total outside width of any vehicle or its load
shall not exceed 102 inches, except as otherwise provided in this
chapter.

(b) Notwithstanding any other provision of law, safety devices which
the Secretary of Transportation determines to be necessary for the
safe and efficient operation of motor vehicles shall not be included
in the calculation of width as specified in subdivision (a).

(c) Any city or county may, by ordinance, prohibit a combination of
vehicles of a total width in excess of 96 inches upon highways under
its jurisdiction. The ordinance shall not be effective until
appropriate signs are erected indicating the streets affected

Maximum Antenna Height on a Vehicle
 

In article ,
Al Lorona wrote:

I have always heard that "13 feet, 6 inches" is a standard for the maximum
height of an antenna mounted on a vehicle.

However, I cannot find a credible source on the web verifying this "fact".
NHTSA, DOT, don't seem to have such an antenna regulation on their
respective web sites. I am not the most skillful user of Google, but my
searches have sure not turned up a reference to this magic number on any
authoritative site. Perhaps there is no national standard, only 50 separate
state standards, and the state with the lowest height limit would then
become the 'national standard'??

I don't think there's a maximum antenna height, per se. However,
there are some standards for the minimum heights of bridges and other
overpasses.

Take a look at

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

Specifically, section 7A specifies that sections of the Interstate in
rural areas must have a clear height of not less than 16 feet, while
some Interstate routes in urban areas can be as low as 14 feet.

I believe that the "13-and-a-fraction foot" height is intended to
ensure that the vehicle can pass along all conforming Interstate
routes without hitting anything... it's a comfortable margin below the
14-foot urban minimum. I've heard "13 feet 9 inches" as well as the
"13 feet 6 inches" figure you mention.

There are some exceptions: Interstate overpasses below the specified
minima. See

http://www.aitaonline.com/Info/Low Clearances.html

for lists.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Maximum Antenna Height on a Vehicle
 

Al Lorona wrote:
... and the state with the lowest height limit would then
become the 'national standard'??

The maximum allowable height rule for the CA
mobile shootouts that I attended was 12.5 feet
from the ground. Don't know if that's the CA
limit or not.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

Maximum Antenna Height on a Vehicle
 

13'6" sounds close. If I needed to know I'd check the maximum height of a
semi-trailer on the hiways and it's probably a standard for a least 48
states.


"Al Lorona" wrote in message
...
I have always heard that "13 feet, 6 inches" is a standard for the maximum
height of an antenna mounted on a vehicle.

However, I cannot find a credible source on the web verifying this "fact".
NHTSA, DOT, don't seem to have such an antenna regulation on their
respective web sites. I am not the most skillful user of Google, but my
searches have sure not turned up a reference to this magic number on any
authoritative site. Perhaps there is no national standard, only 50
separate state standards, and the state with the lowest height limit would
then become the 'national standard'??

Maximum Antenna Height on a Vehicle
 

Cecil Moore wrote:
Al Lorona wrote:
... and the state with the lowest height limit would then
become the 'national standard'??

The maximum allowable height rule for the CA
mobile shootouts that I attended was 12.5 feet
from the ground. Don't know if that's the CA
limit or not.

CA limit is 14 ft (unless you have a "moving permit")
Pilot cars can have a measuring device that's taller, as long as they
don't go slower than 20mi/hr below the speed limit. (presumably this is
in connection with the moving permit for the oversize load that's following.

Your friendly local CHP office will work out the route for you..

Maximum Antenna Height on a Vehicle
 

"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.

Maximum Antenna Height on a Vehicle
 

Al Lorona wrote:
I just called the California Highway Patrol office in Altadena
and found that there really is no right answer.

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. I was stopped by a Maricopa
County deputy sheriff who tried to give me a ticket
for violating some height limit.

I demanded that he put the law section number that I
was violating, on my ticket. After spending about an
hour on his radio, he couldn't do it and let me go.

To be truthful, I had outrun this guy on my Z1B Kawasaki
motorcycle and he was itching to give me a ticket. :-)
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

Maximum Antenna Height on a Vehicle
 

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.


And parking structures.

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.


--
Jim Pennino

Remove .spam.sux to reply.

Maximum Antenna Height on a Vehicle
 

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

Maximum Antenna Height on a Vehicle
 

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

Maximum Antenna Height on a Vehicle
 

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

Maximum Antenna Height on a Vehicle
 

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

Maximum Antenna Height on a Vehicle
 

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.

Maximum Antenna Height on a Vehicle
 

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

Maximum Antenna Height on a Vehicle
 

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. :(

Maximum Antenna Height on a Vehicle
 

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.

Maximum Antenna Height on a Vehicle
 

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.

Maximum Antenna Height on a Vehicle
 

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.

Maximum Antenna Height on a Vehicle
 

"Cecil Moore" wrote in message
...
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

Yeah, I've seen it that way, too.

Years ago, I manged to run the right front corner of my pickup camper into
an overhanging tree branch. No, not at 2AM with a snootful. It was
noontime and I was pulling out a parking space in front of the post office.
That tree would have been an antenna-killer.

Maximum Antenna Height on a Vehicle
 

My bugcatcher is way taller than the interstate limit.

I tie it off at the top, and have a knotted string that I can pull and
hook onto the coat hook inside the car. I let go of it when I stop, and
pull down to drive. Oddly enough it seems to work well enough while
pulled down too.

- 73 de Mike N3LI -