102" whip droop when moving?

[charlie_horse]

Does anybody know how much length a 102" whip loses due to droop/flex at freeway speeds (60-70mph)?

I have one mounted on the bed rail, but due to some mods I'm making, I need to move it to the roof. I'm not really interested in going with a fiberglass whip because I tow a 5th wheel that is 13'2" high and would like the antenna to be above it (plus the 102" works so well!).

I want to make sure I can clear bridges, power lines, etc (yes I know the bridges won't hurt the whip, but I'm concerned about power lines - not just for my own safety but also the well-being of a lot of sensitive on-board electronics).

Thanks in advance!

[The River Rat]

You could always use a bungee cord to keep it wherever you want it.Just wrap it around the antenna and use another bungee cord to adjust the height from your bedrails or any other structure.The only problem with doing that is that your SWR's will likely change.Not that they are not already changing as you drive down the road.
Just bend it to a reasonable height and check your SWR and see what you can come up with.More than likely you will find a compromise because your SWR will definitely rise as you bend the antenna.I've seen a lot of guys do this to their off road vehicles just wrap a bungee cord around the whip and latch the cords to their roll bars and they all work fine I just wouldn't run power that way!!!!


73'rds & Dirty Words
to you and yours
from me and mine
your friendly neighborhood River Rat

[Gadfly]

If you want the whip to remain more upright, I have seen folks slip a piece of rubber hose over the whip to stiffen it. This also helps keep it from rubbing/hitting the paint on your vehicle. :D

73

Gadfly

[jessejamesdallas]

Get a different antenna! Predator 10K will perform as good as your Whip, if not better, and you wont have to worry as much about the height...

[charlie_horse]

Get a different antenna! Predator 10K will perform as good as your Whip, if not better, and you wont have to worry as much about the height...

My issue is actually with the whip being *too* upright. It has to be on top of my 6'8" roof. I'm hoping to keep it, but if it doesn't flex enough I'm going to be smacking power lines.

I'm considering the 10k as an option.. along with a few others. I'm probably going to find a shop that lets me purchase all the antennas I'm considering, test them and then return the ones I don't want.

The problem here is that I have a *very* narrow range of height options. I'm usually towing a 13ft tall 5th wheel, and don't really want to go (much) above the 14ft vehicle limit yet want to have an antenna where at least a small portion of it is higher than the 5th wheel.

When it was on the bedrail, the 102" whip (with spring) was exactly 14' tall.


What is the overall height/length of the 10k? Their web site has no information whatsoever.

Thanks!

[Mudweiser]

I also have a 102" whip and would like to know if hitting a powerline with it really would do anything..... i've heard it doesnt but dont wanna find out myself lol

[Red Warrior]

I also have a 102" whip and would like to know if hitting a powerline with it really would do anything..... i've heard it doesnt but dont wanna find out myself lol

As long as you are in your car and not touching ground, the tires on your vehicle will keep electricity from flowing to ground. Get out of the car with the antenna touching a power line and as soon as your feet touch ground you are toast.

The exception is lightning.

['Doc]

Any 102" whip is going to do some bending at speed. Will that 'bending' be enough for your application? Beats me, probably, maybe.
I haven't seen any 'bare', uninsulated power lines in quite a while, which certainly does not mean that there are none! A momentary contact with the typical power line over a road isn't going to make a huge difference, cause a lot of destruction, except in very unusual circumstances. Can't / won't say it can't happen, but it's just not very likely. I can say that with a 102" whip on top of a vehicle you will do a lot of "hitting things"!
- 'Doc

[MysteryMan]

Doc is on the money.

1) You can change to fiberglass. It's stiffer and won't conduct electricity and shatters on impact.
2) Tilt SS whip forward to stop it leaning back so much in the wind.
3) Shorter antenna.
4) Mount antenna to the front of the truck. But you will be Highly directional to the rear of truck.

[Mudweiser]

I have two fiberglass antennas mounted on each top side of a roll bar in co-phase for a scanner and have the 102" whip mounted on top in the middle of the roll bar in ana-phase for the cb. I like this set up but want to be ABSOLUTELY POSITIVE nothing will happen if it hits power lines. The whip is made of flex-steel and i've hit plent with it anyway so im not afraid to hit stuff just want to make sure that power lines wont do anything to all my electronics and or me.

[Red Warrior]

I have two fiberglass antennas mounted on each top side of a roll bar in co-phase for a scanner and have the 102" whip mounted on top in the middle of the roll bar in ana-phase for the cb. I like this set up but want to be ABSOLUTELY POSITIVE nothing will happen if it hits power lines. The whip is made of flex-steel and i've hit plent with it anyway so im not afraid to hit stuff just want to make sure that power lines wont do anything to all my electronics and or me.

As long as you don't provide a path to ground (like dragging a chain) hitting a power line with the antenna will not damage your radios. Extremely high voltage (as in lightning) will overcome the inherent resistance of the tires and everything in the vehicle will be history.

[Mudweiser]

Thanks i really appreciate it

[White Lightning]

I have two fiberglass antennas mounted on each top side of a roll bar in co-phase for a scanner and have the 102" whip mounted on top in the middle of the roll bar in ana-phase for the cb. I like this set up but want to be ABSOLUTELY POSITIVE nothing will happen if it hits power lines. The whip is made of flex-steel and i've hit plent with it anyway so im not afraid to hit stuff just want to make sure that power lines wont do anything to all my electronics and or me.

I have hit alot of stuff with my whip but no power lines

[TheJerk]

Most, if not all, power lines that you could hit with an antenna will have shielding (i.e. insulation) on them; thereby preventing the possibility of shock.

A little late, but this situation I would opt for something with a load coil, such as a magnetic Wilson 1000/5000 or similar. FWIW, I run a 102 mounted on a toolbox with my 5vr, but I also have an extended pin that prevents the trailer from contacting the antenna (and that's not the same with every trailer out there). The 5vr does not affect my SWR.