help with antenna choice

[QRO]

I purchased a used motorhome and it has a lame little (2foot) antenna mounted on the top of the aluminum ladder on the back of the motorhome.

The coach is all fiberglass so a ground plane to use a good antenna will be a challenge.


I don't need a wide banded antenna... I also dont need antenna to handle handle high power since I do not want to run an amp..

I want good ears!.

I really dont have antenna size limits, BUT I think if I get carried away, antenna MIGHT hit bridges, hehehe .. Motorhome from floor to top of ACs is 12 feet, and I THINK I can get way with mounting the 10K so that the coils are with the roofline or a little above. And have enough antenna wire sticking up above ACs that I might be OK.


Is looking into getting a Predator 10K overkill? Since I will not use it for out of band freqs OR high power I think it might be overkill? My other concern is the fiberglass motorhome... NO GROUND PLANE, this is what concerns me the most?

What route should I try? Am I off base and I should look into something else?


thanks!

 

[Moleculo]

Here's a solution to the no ground-plane problem: Go buy some thin copper sheet and silicone it to the top of the motor-home. Then you can mount an antenna high up on the side of the vehicle with a ground strap attached behind, going up and soldered to the copper sheet. Now you can run any antenna you want.

Moleculo

 

[W5LZ]

Mole',
I think you might run into problems with the 'groundplane' higher than the base of the antenna. Really depends on how much higher it is, but sometimes even a little bit is too much. Wouldn't hurt to give it a try though.
Another solution is to put a horizontal antenna as high over the top of the motorhome as possible (as in inches, not feet). The closer to 18 feet the better, but what ever will fit. Dooubt if it would transmit worth a hoot without a tuner, but ought to give fairly good 'ears'.
And of course, if all else fails, mount an antenna on the back bumper. Won't be the 'best' thing in the world but it'll work.
The problem with any motorhome, fibreglass, metal, whatever, is that there's no really convenient place to mount an antenna. In general, they're all too tall, have metal inner works if not outer skin, a 'crapy' ground, and who knows what else. Another solution is to pull/tow a vehicle behind the thing and mount the antenna on it! Getting a little ridiculous, so I'll quit...
- 'Doc

 

[QRO]

Yes there are concerns, that's why I am asking you guys..

I do not think I can add that antenna on top of the RV.. That will make the antenna tip at 16.5 feet.. If using a 5.5' antenna like the predator 10K.

Antenna needs to be mounted on the rear ladder....


Question for big truck owners: when you guys mount antenna to your mirrors, aren't the truck mirrors mounted to fiberglass shell or body? Wont this be almost the same scenario a me?

 

[Moleculo]

Hey Doc...I guess I didn't explain my idea very well!! LOL I was thinking about mounting an L bracket (mirror mount type) way up on the top of the side of the motorhome so that the base of the antenna and the groundplane would be close to the same height. Then run a shorter antenna like a Wilson 2000 trucker or something. I'm not sure if that makes the overall height too high on his motorhome or not, but it would be close.

 

[jessejamesdallas]

Dont know what kind of mirror's you have, but that would be the way to go...dont even think of putting a antenna on the roof of that thing...been there done that...you will be hitting everything from tree limbs to traffic lights, to telephone wires, and bridges.

Best thing to do, would be to go with the Predator 10K, dual coil, and either the 9" or 12" shaft, mounted on the mirrors. You can angle them out some, this will help lower the higth some. Truckers do this all the time with the 10K. You will probley need to run ground straps from the mounts to the frame of the truck.

The 10K is made for "High-Power", but also works very well with stock barefoot radios. The 10K will bring any radio to life, with or without running a "Zillion" watt's! :!:

If your going to run...run with the best! Predator 10K

 

[QRO]

jessejamesdallas,

I think I might look into 2 antennas mounted on the mirrors.. But I really cant have 2 predators, they look way to obvious with the large coils. Not to mention overkill with the power level I will be running.

Maybe co-phasing two firesticks or wilson 2000's?

My motorhome body is 102 inches wide, and the mirros stick out a little farther out on each side.

The problem I saw about this install, was the way my mirros are... they are way too thick to use a standard mirror mount, but I think they are too thin and WONT allow any real mount that has coax connector and coax INSIDE the mirror assembly.

UNLESS there are mounts with a 90 deg bend? The mount will install properly but I dont have room to attach coax.

 

[QRO]

humm.... seems like mounts are available that use a wire with remote coax connector instead of that coax connector right on the mount? if this is the case, I think it will work..


Another question with cophased antennas, dont the antennas need to see each other or something like that? I dont think my motorhomes mirros are AS HIGH as bid trucks mirrors.

I will post a PIC of the front of the RV soon...

 

[QRO]

so you guys can see what I am working with...

here is a picture....

http://community.webshots.com/user

 

[Mr Clean]

Does it have a ladder on the back? Ground the ladder to the frame. Mount it on side of step angled back for going down the road and straight up when you get to your destination.

 

[jessejamesdallas]

First, on co-phase, no, the antennas dont need to see each other. But! You will need a co-phased coax. You can find it @ www.cbcity.com/Here is the page link: catalog page

But most truckers that still use this set-up, will only have "One" of the antennas actualy hooked-up...the other is mostly just for look's.

What you may want to do, is go by a RV dealer, and ask them what they recomend. They may have something that would work. Or when you pull into a RV park, look around at the other RV's and see what they have. Still think you should be able to find something that will work on those mirrors.

One more thing. Belive it or not. the Predator antenna realy is not that much "over-kill", on that rig of yours, I dought it very seriously, anyone will even notice it. useing the 12'' shaft, and Dual Coil 10K, it would be shorter than a Wilson antenna, and blend-in more, than a "Bright White" Firestic...(IMO)

But hell.....Im just a 10K kinda guy! :beer

 

[Moleculo]

Out of curiosity, what is the height of the motorhome to the roof?

BTW, that mount you were talking about that uses wire with "remote coax": You run the coax to the mount, then split the braid from the center conductor and attach the center conductor to the bottom bolt and the braid to the antenna bracket or to ground.

 

[mrcoily]

I purchased a used motorhome and it has a lame little (2foot) antenna mounted on the top of the aluminum ladder on the back of the motorhome.

The coach is all fiberglass so a ground plane to use a good antenna will be a challenge.


I don't need a wide banded antenna... I also dont need antenna to handle handle high power since I do not want to run an amp..

I want good ears!.

I really dont have antenna size limits, BUT I think if I get carried away, antenna MIGHT hit bridges, hehehe .. Motorhome from floor to top of ACs is 12 feet, and I THINK I can get way with mounting the 10K so that the coils are with the roofline or a little above. And have enough antenna wire sticking up above ACs that I might be OK.


Is looking into getting a Predator 10K overkill? Since I will not use it for out of band freqs OR high power I think it might be overkill? My other concern is the fiberglass motorhome... NO GROUND PLANE, this is what concerns me the most?

What route should I try? Am I off base and I should look into something else?


thanks!

Well i would say just go with a standard setup on a motor home, your not going to have alot of options as far as mounting goes,mirror mounts,ladder,rack,spare tire mount,maybe go off the side with a ballmount and a whip, might be a little scary with a whip flapping all over Should be able to set up a couple of 4 foot antennas.And at that size they all work about the same,maybe a couple of "quad wraps" my favorite in wire antennas...And you could always shoot me an e-mail and i can hook you up with a Coily truck antenna there short and i sell em all day long,they work great Not sure where you would mount it, and that can affect tuning but!I'll let you try it out first! If you don't like it send it back if you like it send me a check..73sss www.mrcoily.com :Wavey
The best antennas are Built in the Nw Corner!

 

[QRO]

good info guys!

jessejamesdallas: I changed my mind on the coil antenna types because they need a ground plane (wich I do not have)
If I can somehow make it work , I would rather Install that 1 antenna in the rear ladder. That was my first choice actually.

Also, the dealer says they use the little tiny 1 or 2 foot antennas, they do not know much about good antenna setups.

Moleculo: Floor to roof is 11 feet. And add 1 more foot for the ACs and stuff mounted up there.

mrcoily: no outside spare, no rack, and a side mount up high? YIKES! it will get ripped off for sure.

I think mounting options are mirrors or rear ladder... But it goes back to my orginal issue.. ground plane...

-------------

Also will coax length add to the tunning issue? If I mount antenna up high on the ladder, I will need a lot of coax ro make it up front. way past the suggested 18 feet..

Motorhome is 37.5 feet long Bumper to Bumper.

 

[Moleculo]

You could get two antennas and mount one vertical facing up and one vertical facing down. Someone makes a dipole bracket for mobile antennas that you could figure out how to mount to the top of the ladder. This way, you would have one antenna facing down behind the ladder, and one facing up. Even fiberglass antennas would work. Essentially you're making a mobile dipole.

Or, it seems that you have about 3' of antenna clearance to keep the overall height at 14'. A short antenna like a Wilson 2000 trucker mounted on top of the ladder, with thin copper or aluminum sheet siliconed to the roof and ground strap run from ladder to sheet would work.