TLCA Max Antenna Length

NMC_EXP

Explorer
The TLCA vehicle inspection checklist stipulates a maximum antenna length of 54".

Anyone know the specifics behind this?
 

DaveInDenver

Middle Income Semi-Redneck
It goes back to the days when people would run full 102" CB whips. It can be dangerous to spotters and spectators to have them whipping around unsecured.
 

opg4759

New member
I've witnessed a spotter getting smacked on a trail with a 102" whip, broke his nose and a concussion when he hit the ground with his head. Not a trivial concern.
 

NMC_EXP

Explorer
I've witnessed a spotter getting smacked on a trail with a 102" whip, broke his nose and a concussion when he hit the ground with his head. Not a trivial concern.

Maybe TLCA ought to ban Hi Lift jacks and steel winch line as well?
 

mtnbike28

Expedition Leader
"Maybe TLCA ought to ban Hi Lift jacks and steel winch line as well? "
No I hate being around wipe antennas in the woods... when someone pulls out a jack, or a winch line I know there is danger possible. When I am standing beside a trail to let a truck go by and get hit by an antenna I couldn't see - it's a safety issue. If it bugs you that much, don't go to TLCA events or rides.
 

1911

Expedition Leader
Of all the TLCA events I've registered/attended, I've never actually had a vehicle inspection of any kind. But I don't run a big whip either.
 

NMC_EXP

Explorer
If it bugs you that much, don't go to TLCA events or rides.

Now why didn't I think of that?

Reckon I'll buy a pair of 102" whips. Mount them on either side, and attach a black "take no prisoners" flag on each. Then join Pirate 4X4 and terrorize everyone on the trails.
 

NMC_EXP

Explorer
Of all the TLCA events I've registered/attended, I've never actually had a vehicle inspection of any kind. But I don't run a big whip either.

I still have a 102" whip on my FJ40 but the radio is long gone. Used the 40 among other things to roundup my uncles cattle out of the timber. These antennas are unbreakable.

Gathered some empirical data on 102" whip whippiness today. I pulled the tip of the antenna down level with the rain gutter and let it go a few times. Swung through its arc and the tip would get almost to gutter level on the other end on the first oscillation. On the first return trip it went maybe 30° past TDC, then quickly dampened out.

The FJ60 is the prime mover now. I was trying to decide what to do about 2 way communication in that thing when I saw the TLCA rule and was surprised. It is hard for me to conjure how anyone could get hurt by one. But like they say, Murphy was an optimist.
 

4x4junkie

Explorer
I've been bopped on the shoulder once by a friend's 102" fiberglass whip mounted low at the rear quarter of his YJ. It caught me off guard, but didn't inflict pain in any way whatsoever. I will say the rule does seem to have some merit, but to restrict it to 54" is short-sighted (effectively that bans any & all antennas that have any chance of working decent).

IMO, I think something like this should be case-by-case (perhaps based on how far an antenna can intrude into a 3 foot buffer zone around the vehicle). I know as an example a 5.5' (66") fiberglass antenna mounted centered up at the roof is not going to present a hazard to bystanders, but the same antenna on a side-quarter still has a very small chance of it (any antenna should be mounted up high anyway, just for the simple fact that it works better even if nothing else).

In a way I have to sortof agree with mtnbike28. I tend to avoid club/association runs simply because of all the rules, politics, and structured schedules that go with it. I find FAR more enjoyment comes out of a run when it's a get-together with friends or an impromptu meet-up and we go out exploring/wheeling on our own terms (you get to see a heck of a lot more too, since you can at any time just pull off with your buds and check out that mine/ruin/cave/whatever you see).
 

NMC_EXP

Explorer
In a way I have to sortof agree with mtnbike28. I tend to avoid club/association runs simply because of all the rules, politics, and structured schedules that go with it. I find FAR more enjoyment comes out of a run when it's a get-together with friends or an impromptu meet-up and we go out exploring/wheeling on our own terms (you get to see a heck of a lot more too, since you can at any time just pull off with your buds and check out that mine/ruin/cave/whatever you see).

So far I've never participated in a club event. There is one annual trail maintenance outing in my area that interests me but in general, crowds leave me cold.
 

1911

Expedition Leader
I was trying to decide what to do about 2 way communication in that thing when I saw the TLCA rule and was surprised.

Many TLCA chapters and events are moving to 2 meters ham, but cb is still the lowest common denominator of trail commo. In a small enough group, a cb with a tuned 3 or 4' antenna will probably be good enough.
 

NMC_EXP

Explorer
Many TLCA chapters and events are moving to 2 meters ham, but cb is still the lowest common denominator of trail commo. In a small enough group, a cb with a tuned 3 or 4' antenna will probably be good enough.

The FJ60 came equipped with a CB. The antenna is on the front bumper and is only slightly higher than the hood. That got me thinking about a taller antenna.

I'm working up the ambition to study for and take the Technician exam and will be shopping for a 2M radio. Will leave the CB in place as well.
 

DaveInDenver

Middle Income Semi-Redneck
Your experiment doesn't model an antenna swinging back and forth with a vehicle going through an obstacle. But regardless, TLCA is usually reactive so probably someone got smacked at some point and thus the rule was added. The 102" whip is a very useful as the designed antenna for mobile tuners like the FC-40, AH-2, EDX-2, etc. If you showed up with one and demonstrated a way to secure it (e.g. similar to the AS-1729 in NVIS mode) for driving down the trail I'm fairly certain no one would have a problem with it.

JohnnysDiagram4-670x390.png


They include a clip and leader that you hook over the whip and tie down to the front.

tie-down.jpg


This is the preferred orientation for an HF antenna while mobile anyway. It guarantees that your pattern is highly polarized along the Z aspect and that coverage is local, IOW all skywave with very little skip and no ground wave. This means all your power is orthogonal to the Earth and is mostly reflected back off the ionosphere. It essentially creates a couple of hundred mile radius pattern around you.
 
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NMC_EXP

Explorer
Thanks for the info.

My quick & dirty test seemed to be a worst case scenario of driving under a roof high limb or other obstruction (antenna is mounted on left rear 1/4 panel on a "pot belly" spring base). Do these whips get into a more severe oscillation due to rough trail conditions?

I have one of those GI antenna tie downs left over from my M1009 CUCV.
 

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