Why we tell people to NOT use magmounts

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mmckenna

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Out of curiosity, I wondered what the 'pros' did. Wranglers are used by law enforcement etc where rugged terrain has to be patrolled. I came across a picture of a US Border Patrol JK. They drilled a hole right in the plastic top. I'm guessing they used a half wave. The thought of doing something like this crossed my mind, but my top is rarely on in the summer so it wouldn't be practical.

Either a thick mount NMO with a half wave, or they did a thick mount with a conductive sheet on the inside of the top. I've done that on UTV's with plastic tops on them.
One of the antenna manufacturers, maybe Laird, sells a 6" disk with a 3/4" hole in the center for doing UHF and higher frequency antennas.
 

mmckenna

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Yes, that's a Laird or PCTEL 1/2 wave VHF antenna in the provided picture.

Yeah. 0dB without the ground plane, or 2.4dB with a ground plane. I've noticed BLM likes the half wave antennas, also. A bit of gain and some pretty good bandwidth. Cut them for about 160MHz and they'll do the 150 and 160 ranges just fine.
 

KK6ZTE

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Yeah. 0dB without the ground plane, or 2.4dB with a ground plane. I've noticed BLM likes the half wave antennas, also. A bit of gain and some pretty good bandwidth. Cut them for about 160MHz and they'll do the 150 and 160 ranges just fine.
I use them all day long on fiberglass body Peterbilt trucks (cement trucks/trash trucks/etc) on VHF. I'll use the PCTEL K332 discs on UHF.
 

03msc

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A lot of the comms installed in Jeeps (Wranglers, I mean) are mostly used for short-range comms while they're out on the trail with their friends, etc. In those cases, whether it's CB, GMRS, or Ham, the best performance isn't necessarily required since it's likely <1 mile that they're talking. Personally, I'd want to do it as best as I could and, unless it was for just a short period, that would involve one of the above mentioned vehicle-specific mounts or one like I linked to earlier and not a mag mount. As I said earlier, each person has to decide what they want to do and if they are OK with mag mount then that's their choice. As discussed, Wranglers are a different animal and sort of an anomaly in this discussion because of the removable roofs.

I greatly respect those who say "I know the trade-offs but I choose to use a mag mount and I'm fine with the results I get" vs someone who says "this thread is stupid, mag mounts are fine and no worse than a drilled NMO in the roof" as many of us have seen others say in other threads or maybe even earlier in this one. One is respectable while the second is downright silly.
 

KK6ZTE

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A lot of the comms installed in Jeeps (Wranglers, I mean) are mostly used for short-range comms while they're out on the trail with their friends, etc. In those cases, whether it's CB, GMRS, or Ham, the best performance isn't necessarily required since it's likely <1 mile that they're talking. Personally, I'd want to do it as best as I could and, unless it was for just a short period, that would involve one of the above mentioned vehicle-specific mounts or one like I linked to earlier and not a mag mount. As I said earlier, each person has to decide what they want to do and if they are OK with mag mount then that's their choice. As discussed, Wranglers are a different animal and sort of an anomaly in this discussion because of the removable roofs.

I greatly respect those who say "I know the trade-offs but I choose to use a mag mount and I'm fine with the results I get" vs someone who says "this thread is stupid, mag mounts are fine and no worse than a drilled NMO in the roof" as many of us have seen others say in other threads or maybe even earlier in this one. One is respectable while the second is downright silly.
Very well put.

Perspective is important.
 

mmckenna

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In those cases, whether it's CB, GMRS, or Ham, the best performance isn't necessarily required since it's likely <1 mile that they're talking.

Very true, and a good point.

I've seen a lot of 'overlanders' that get their ham ticket and a dual band radio for use in case they get lost/stuck out in the middle of nowhere. They usually are running some cheap-a$$ mag mount or some bracket boogered together to mount an antenna on a roof rack with improper ground plane. I know couple of people that have done this, and trying to help them has been fruitless.

For short range use, sure, use a low profile antenna and get a mile or two. But for those relying on the radio for 'emergencies', a mile may not be good enough. Squeezing the most you can out of your radio installation may become very important.
 

03msc

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Squeezing the most you can out of your radio installation may become very important.

Yes and this is what many don't understand. I think that some genuinely don't think that there legitimately is a performance difference between a mag mount and a properly installed antenna on the roof. If they do and are fine with the limited performance then that's their choice but some just don't know.
 

jeepsandradios

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I and my wife has had jeeps for quite some time. On my last CJ I installed a half wave in the center of the fiberglass top and used a piece of sheet metal on the outside painted black with a thick mount. I never removed the top on that CJ and it worked great on VHF. When my wife got her JK the new tops are not flat so had to use the metal inside but did the same. We do take top off in summer so I installed a N bulkhead mount near the door area. When i pull the hard top I install a mount to the center of the roll bar and run the cable to the bulk head. IT works great on the roll bar. In SAR 90% of our comms are simplex so any way I can manage a little extra I do. As reference I did try a fender mount (vehicle specific) and also a clip mount on the rear swing door and neither worked as well as the roof.

Unfortunately when i got my new JT we went with the soft top so killed a similar idea. I installed a APX8500 so didn't have many options. My solution was a back rack with with a Larsen thick mount. I run the Larsen tri band antenna and while it works good on UHF/800 VHF does suffer. I have swept the 1/4 wave VHF, half wave, and a few other antennas and the larsen is about a match to the 1/4 wave so thats where im at currently.

As you said alot of the jeep world doesn't care as long as they can talk to the guy on the trail near them.

(Oh and the new JT is mostly aluminum so mag mounts are a thing of the past now...)
 

Ensnared

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The rubber bottoms don't really help - they still trap moisture as well as micro-particles, etc. The K0BG.com site explains it all better than I.
[/QUOTE

If you maintain you antenna and pick it up and clean out the moisture, no problem. I have been using these antennas for years, both CB and Scanner. If it pleases my wife, by the absence of a marred finish, I am quite satisfied. That is all that counts. LOL.

Thanks for your reply.
 

enine

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Seems odd that my mag mount antenna didn't cause any paint damage after being on there for years, I just had to wife off the scuff marks, maybe the OP should be telling people to not buy VW's :)

What do you do for a good ground plane when you can't mount on the roof due to needing to be able to carry things like kayaks, etc? Where is the best mount. I'm using a fender mount currently.
 

11th

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These 2 photos show why NOT to use magmounts. This is my 2014 TDI Jetta, that I have used a magmount on for 2 years.

With all respect I have seen damage on fender lip mounts, there are pics on the net of that kind of damage as well.
And if you use either a decal mounted onto the body part, or better yet the newer 3m product designed to protect paint, you are probably not going to see those scratches at all. I think if you get some kind of detritus or particle on the bottom of the mount and then mag mount directly to car you will see those scratches from either tiny amount of movement or larger movement if you drag it off to remove the mag mount. But if you have a plastic material on the vehicle itself in the shape of the mount surface, the detritus will scratch the vinyl decal material and not the paint.

So it kind of depends on your needs. Vehicles like jeep wranglers get hoods or fender body damage worse than that, including requiring bondo filler from using fender or hood bracket mounts too. The fender mounts on jeeps are almost always below hood heigth and also generally mean the lower part of the antenna an inch from 4" or so of nearly vertical metal So avoid mag mounts if you can, but sometimes they are the least bad alternative.
 

03msc

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Unless it's temporary, don't use mag mounts. Simplest way to put it.

Read the whole thread if you haven't as it answers a lot of questions and responds to claims saying otherwise.

Bottom line is...it's your vehicle so do what you want but you won't convince us otherwise; years of experience adds up to a common knowledge.
 

11th

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Unless it's temporary, don't use mag mounts. Simplest way to put it.
Read the whole thread if you haven't as it answers a lot of questions and responds to claims saying otherwise.
Bottom line is...it's your vehicle so do what you want but you won't convince us otherwise; years of experience adds up to a common knowledge.
Sure, but one can also say, on a jeep, unless it is temporary and won't be used on a trail or off road in anyway don't use a lip on fender or hood, and don't use a side cowl mount. It is also that simple.

I think your advice in general is sage, well thought out and expert. OK?

I am just pointing out that when it comes to damage, on jeeps you see more instances of damage -- and more costly damage -- from side mounting, be it hood lip, side cowl or fender mount mount, than from magnetic mounts on the center of the cowl. I've just been simplex on a handi with no antenna and am looking at various options for an external at the moment. But I have been on plenty of trail rides and have observed damage. On a jeep (off road but not garages) a rear mount is safest. Side mounts, which are the alternative to rear or magnetic, are the worst (again in terms of damage risk). Magnetic on the center of the cowl just south of the hoodline are relatively safe compared to side mount.

I was responding to a damage picture, not a function issue where I 100% agree
 

03msc

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Yes, and like I said each person has to decide what they're OK with on their vehicle. Of course, we're not only talking damage - mag mount performance is also inferior to better mounts. Not as bad as the old "through the glass" window mounts but inferior to better mounts.

Users just have to be willing to accept the performance hit and potential for damage. If they are fine with that then that is their choice.

Jeeps are perhaps the most difficult to mount an antenna for superior results because of the reasons you mentioned - removeable tops, etc. Sometimes it is necessary to compromise on performance to have an antenna. Most seem to mount them along the edges of the hood, at least that's what I often see in the photos in overlanding groups and such. Again...the compromise.
 

11th

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Yes, and like I said each person has to decide what they're OK with on their vehicle. Of course, we're not only talking damage - mag mount performance is also inferior to better mounts. Not as bad as the old "through the glass" window mounts but inferior to better mounts.

Users just have to be willing to accept the performance hit and potential for damage. If they are fine with that then that is their choice.

Jeeps are perhaps the most difficult to mount an antenna for superior results because of the reasons you mentioned - removeable tops, etc. Sometimes it is necessary to compromise on performance to have an antenna. Most seem to mount them along the edges of the hood, at least that's what I often see in the photos in overlanding groups and such. Again...the compromise

I am sorry if I came off seeming to reduce the value of information you provided. It is all great info and certainly 99% above my level of knowledge.

I was attempting to address the mag mount damage only because I have been a half a dozen large participant trial rides this winter with my handi with a goal of getting an antenna myself and made a pretty comprehensive look at the various options I saw. People with the mag mounts had not had the damage depicted.

I definitely saw a LOT of mountings on Jeeps that were plain ridiculous, like with half the antenna sandwiched between 175 degrees of a foot of vertical metal tailgate 2" away in front, and more than a foot of spare tire's wheel, and maybe even steel belt in the spare tire itself. blocking 1750 degrees to the rear. So I do get your point on performance!

If you would like, I have put up a topic here on jeeps and dual band uhf/vhf mount methods, trying to address all or most of what I have seen in mounting methods and my very limited take on the pros and cons of each. I would very much appreciate your feedback there on that!
 
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