Magnetic mount antenna lesson

Joined
Dec 10, 2003
Messages
423
Location
Lafayette, IN
I made a very important discovery Wednesday somewhere on IL9. As a semi passed me going the other way, I got smacked with a healthy gust of wind. So healthy that it overcame the magnet on my antenna and left it dangling off the right side of my car. I was lucky though, and got to learn my lesson the easy way. The distance from the door to the center of the roof plus the length of the antenna was greater than the distance from the top of the door to the road surface. Therefore, my antenna escaped damage. Those of you who use mag mount antennas -- before you leave check to make sure that if the magnet can't hold to the roof that you won't end up dragging your antenna across the roadway...I don't imagine that will help your signal any. It's not something I ever thought about until today, but now it will be routine for me, right along with checking engine fluids.


Ben
 
Yes, I lost a nice tri-band mobile mag-mount last year after passing an oncoming semi on a 60mph 2-lane, 2-way road in northern OK... I was running the antenna coax from the trunk to the middle of the roof, which meant that when it flew off, and it smacked the road, splintered into several pieces. To make matters worse, the magnet smashed apart as well, leaving not only me without a magnet, but also causing for some high-speed metal debris, which is certainly a safety concern.

What did I do? I still run the antenna from my trunk to the center of the roof, but I did buy a very heavy-duty magnet, so I should no longer have the problem of the mag mount giving way. I've passed many trucks now at high speeds and it hasn't budged yet, so I strongly suggest that folks "upgrade" to a stronger magnet mount, especially for the Radioshack scanner antenna type of mag mounts, which are pretty weak I've found...
 
This is one of the exact reasons I always use an nmo mount whenever possible. The only magmount I have now is my little wifi antenna that is so small anyway I don't leave it out going down the road usually.
 
I have 2 magnet mount antennas on top of the car, both have been there for about a year now. I considered them very sturdy until last Monday (21st), while driving down US-69 near Pittsburg, KS, they blew off when two dump trucks who were drifting each other went in the opposite direction along the 2 lane roadway. Unfortunately, I am not going to drill in the roof of the car (yet), but may consider that option down the road.
 
I made a very important discovery Wednesday somewhere on IL9. As a semi passed me going the other way, I got smacked with a healthy gust of wind. So healthy that it overcame the magnet on my antenna and left it dangling off the right side of my car. I was lucky though, and got to learn my lesson the easy way. The distance from the door to the center of the roof plus the length of the antenna was greater than the distance from the top of the door to the road surface. Therefore, my antenna escaped damage. Those of you who use mag mount antennas -- before you leave check to make sure that if the magnet can't hold to the roof that you won't end up dragging your antenna across the roadway...I don't imagine that will help your signal any. It's not something I ever thought about until today, but now it will be routine for me, right along with checking engine fluids.


Ben

Oooo, This happened to me also. I had a cheapo radio shack antenna on the car. What brand of mag mount were you using on your vehicle ???
 
I've "lost" quite a few mag mounts. I still use them, but manage to keep them on a very short leash. Now when they topple over to the the "trucker gust front" they smack the camper shell and go no further. Of course it's an older sheet metal shell so I hear it right off the bat. Usually gets my undivided attention for at least a few moments.
 
I lost a tire once to a situation exactly like that! The antenna came crashing off the roof and ended up (somehow) slicing my tire. This wasn't on a chase, but we were on our way to Dallas and had to get a replacement tire to continue our journey. This happened near Burlington, Colorado at 3:00am and really sucked! Since then, I have twist-tied my wires together and left all the slack wires in the trunk so that if an antenna bites the dust, it in reality can only fall over instead of crashing off the roof!
 
This has happened to me several times too. It scares me to death when it happens ... think the antenna is going to come flying through one of the windows. Now we strap the mag mounts to the luggage rack ... we position in them in the back two corners of the rack so the wind is pushing them against the sides of the rack, and then we use bungee cords to wrap the bases against the rack ... seems to do the trick. I've actually had inflow winds blow them off too ... not fun.
 
Originally posted by Mike Peregrine
This has happened to me several times too. It scares me to death when it happens ... think the antenna is going to come flying through one of the windows. Now we strap the mag mounts to the luggage rack ... we position in them in the back two corners of the rack so the wind is pushing them against the sides of the rack, and then we use bungee cords to wrap the bases against the rack ... seems to do the trick. I've actually had inflow winds blow them off too ... not fun.

That was EXACTLY what happened to me, passed a truck and it blew off and shattered the back window!
 
Speaking of magnetic antennas, are any of you that own a wxworx system mounting the receiver antenna on the exterior of your vehicle? I was impressed with the strength of that little antenna's magnets. It was quiet an effort to get the thing back off the car when I tested it the first time, lol
 
Originally posted by Scott Taylor
Speaking of magnetic antennas, are any of you that own a wxworx system mounting the receiver antenna on the exterior of your vehicle? I was impressed with the strength of that little antenna's magnets. It was quiet an effort to get the thing back off the car when I tested it the first time, lol

That little bugger is strong isn't it. I haven't decided if it's just THAT good of a magnet, or if it's because the antenna is so small in the first place, or if it really is just that strong of a magnet. I have it stuck on the gas meter outside the house here using it here at home.
 
I use a micro antenna available here in the UK 2m and 70cms,good for 50W used to use it on my old car and it stayed stable, ie didn't even budge at 110mph down a German autobahn. I swear by that little beast, it is also the some size base as my external cellphone one. If I want more power I just go for the big whip mounted on the spare tire bracket on the tailgate.
 
Originally posted by Stephanie Koles
Oooo, This happened to me also. I had a cheapo radio shack antenna on the car. What brand of mag mount were you using on your vehicle ???
It's a Jetstream dual-band. The magnet is pretty decent, I've accidentally driven it into a parking garage roof and it held. I've used those Radio Shack antennas before to boost my NWR reception...every time I go around a turn it sounds like it's going to fly off.


Ben
 
I in fact have 3 magnet mount antennas. One for my Wi-fi card, one for the scanner and one for the HAM radio. Last night the wind was really howling, jeep was rocking it was blowing so hard while watching the lightning. Decided to drive into the wind, antennas still held strong going 55mph into those winds. Can't imagine how fast the wind actually was combined. I zip tie my wires to the luggage rack so if they ever do decide to come off, they aren't going far. :D
 
I use several mag mount antennas. I run the wires so the most distant mag mount wire runs nect to the net mag mount and so forth. I use cable ties to attach all wires together. This greatly shortens the leash. Using this method, I haven't lost an antenna yet.
 
I just bought a radio shack scanner antenna and put it on my trunk, seems to be holding up pretty well so far, but it sounds like I should maybe move it.[/quote]
 
I had a Ruffrider magnet (MFJ) on my truck a few years ago, 5" I think, I had a Comet SBB-7 (big antenna) Low entrance to a parking garage the antenna snapped off just below the foldover, magnet didnt budge!!
I almost had to use a crowbar to get it off.
 
Think about this... if wind can do that, what about everyday vibration? Any of you who have had a mag mount in the same place for more than a few months, pull the mount off and look at where it was. Do you see those scratches? You may even see some rust starting as tha mag mount has scratched dowm to the bare metal.
*steps off of soap box*

Not trying to be harsh, but I've damaged one of my vehicles with a mag mount before. See some of my other posts for alternatives to mag mounts and drilling (which IS the best, but some don't want to which is understandable)

Now, if you have'nt already, get your ham ticket and play radio!
 
Something to consider...you can mount an NMO antenna using a "L" bracket and attach it to the trunk well with 2 small screws. No visible holes this way.
 
I declare some voodoo action here...

Yesterday, on my way south on I35 towards Ardmore, a plastic bag on the road kicked up behind the vehicle ahead of me, smacked into my Comet SB15 tri-band mag mount, and provided just enough enhanced wind resistance to knock the magnet off. Smack. The antenna busted in half and the magnet busted into several different pieces. I specifically bought a very heavy-duty magnet mount which held like a rock, but that's without a stupid plastic bag stuck to it... $150 down the drain...
 
I declare some voodoo action here...

Yesterday, on my way south on I35 towards Ardmore, a plastic bag on the road kicked up behind the vehicle ahead of me, smacked into my Comet SBB7 mag mount, and provided just enough enhanced wind resistance to knock the magnet off. Smack. The antenna busted in half and the magnet busted into several different pieces. I specifically bought a very heavy-duty magnet mount which held like a rock, but that's without a stupid plastic bag stuck to it... $150 down the drain...

Dang man that sucks. An SBB7 at that! Sooo, you gonna take the plunge and drill now? hehe
 
I got a big honkin' maknet mount at a truck stop for my Wilson cell antenna. It's gotta be 6, maybe 7 inches in diameter. Cost me $30 but has not blown over yet. Lost my last Wilson to a power line last year near Geary, OK. It WAS rigid mounted so this time I decided to find something that would give. If I could only stay away from those downed power lines!
 
For those who like mag mount type systems, you may want to look into modifying a welder's magnet for the antenna. You can find them with 70lb+ capacity, I think. Pretty grippy.
 
I had recently bought a K40 CB whip antenna with what i thought was the correct mag base for the thing. It hled on very well at 55-65mph once i hit 70mph it fell off. it was on a short leash so it didnt go any where. But i ended up getting a 3/8th trunk lip mount and that works wonderfull i can go 90mph and it stays firm and in place. I just tested the 90mph i dont go 90mph like some people i chased with before.
 
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