Going Mobile with HAM

[MobTuff]

I finally got my HAM licence a couple months ago. KK6ATA! I've been using my Yaesu FT-2900 with great success. I really like the radio. I have a J-Pole mounted to my roof that brings in signal great. I was thinking about getting another FT-2900 for the truck but I can't decided on a place to mount it in my 1st gen Tundra. So I've decided on the FT-7900 for the truck due to the faceplate detaching from the radio.

Anyhow, I'm really undecided on selecting an antenna and mount! I've gone through the entire sticky for 2m antennas and still don't know what to get. I've decided to either do a fender mount in the seam of the hood or mount to my lumber rack. I'm still new to HAM but would mounting to my lumber rack be a bad idea since there isn't a good ground? What's this I hear about ground independant antennas? I have the Rack It 3000 so I was thinking about a tube kinda mount.

Or if I go fender I was thinking a bracket (DaveInDenver mentioned this one) or a lip type mount like the Diamond K400.

Does anybody have a pickup with a fender mount? Or have a tubular rack with an antenna mounted? Pictures would be great.

 

[tanglefoot]

Congrats on the license!

A lumber rack should be a sufficient ground for an antenna. It's one of those that extends over cab and attaches to the bed rails, right?

I've just always used magnetic mount antennas. They're mighty easy to install and move easily between vehicles.

 

[MobTuff]

Thanks! I'm excited to get my mobile setup going because I spend so much time in the truck. I'm leaning away from the rack mount due to the larger sized tubing used and ladders and materials coming on and off the truck. I'm thinking the fender mount might be the way to go and still be able to have a longer antenna.

I saw another member DaveInDenver comment that this is a good bracket to use with Toyota trucks.
http://www.gamiviti.com/html/products_antennamounts.html

So any suggestions on a 1/2 wave whip antenna?

 

[1911]

So any suggestions on a 1/2 wave whip antenna?

Congratulations on your ticket!

BTW it's the ground plane that you need to have some thought for, not (just) the electrical ground. Two completely different things. Fortunately, your choice of a 1-/2 antenna is a good one in this instance because they are much more forgiving of a lack of ground plane than a 5/8-wave or 1/4-wave antenna.

The 1/2-wave 2M whip I've had the best success with (and still use on my Land Cruiser) is the Larsen NMO-150, though you have to specify the 1/2-wave model because for some reason they use the same model number for their 5/8-wave mobile antenna also. It is tunable by cutting the whip to length, so be sure to use a good antenna analyzer/SWR meter on your installation.

 

[MobTuff]

Ok great. Yeah I chose the 1/2 due to the forgiveness in ground plane. Also the larger antennas look cooler in my opinion :sombrero:. This one looks smaller is that due to the base being thicker right?

What do you think about my question here: http://www.expeditionportal.com/forum/threads/100964-Going-Mobile-with-HAM?p=1319409#post1319409

 

[1911]

Ok great. Yeah I chose the 1/2 due to the forgiveness in ground plane. Also the larger antennas look cooler in my opinion :sombrero:. This one looks smaller is that due to the base being thicker right?

The thicker base on the Larsen NMO-150 is just the NMO mount; it's just a simple 1/2-wave whip. 2 meters wavelength = 6.56 feet = 78.7". 78.7"/2 = 39.4", so a simple 1/2-wave 2M antenna is going to be a whip about 39.4" long (which the Larsen NMO-150 1/2-wave is).

What do you think about my question here: http://www.expeditionportal.com/forum/threads/100964-Going-Mobile-with-HAM?p=1319409#post1319409

That link is just back to this thread - did you mean a different one?

 

[MobTuff]

Whoops I meant this post
http://www.expeditionportal.com/forum/threads/10411-2M-Antenna-Recommendations?p=1319419#post1319419

I think I was getting all the antenna model numbers mixed up. The one I think you are referring to is the Larsen NMO150/450C? Can anyone tell what the difference between the NMO2/70B and the NMO150-450C is other than the center coil? It looks like one might be silver and one black? I'm thinking one of these might be the one.

My other concern is how to mount the antenna. In the linked post I showed a bracket I'm thinking of using with an NMO mount. After looking at more close up pictures it looks like these NMO mounts tighten over a 3/4 hole? So if I purchase an NMO mount/cable combo with that bracket I should be good to go? Is there a specific type of nmo mount to purchase?

 

[Mash5]

I use a safari style rack with my 2m antenna on the front center. It works great as a ground plane. I think your rack would work just fine, though it could be in the way of using the rack maybe. If you are not mounting it through the roof why not use a UHF mount. I think the connection is a bit more stout and you should save a few dollars.

 

[DaveInDenver]

The NMO2/70 is tuned for amateur 2m and 70cm bands. THe NMO150/450 centers at 150MHz and 450MHz, which means it seems designed for commercial bands (at least on VHF). The two are probably essentially the same parts, but I'm not sure Larsen dual band antennas are easily re-tuned. I have a NMO 2/70 with the open coil and I don't recall any way to separately tune it beyond the overall length of the whip, although the closed coiled models might be different (I don't remember).

Fender lip mounts are OK but not my preferred choice. I like punching a hole in the roof and doing NMOs right. But a rack is good and solid. The main issue might be height, which is honestly also a concern with them on the roof. You have to use flexible antennas on a daily basis to prevent breaking them in a momentary lapse of memory. That's really the advantage of fender mounts, they are low and you don't have to be concerned parking in garages or going through drive-thrus. So all that said, I run the Toyota-specific ones I've mentioned and they work well.

 

[MobTuff]

Thanks for the reply! Do you find the NMO2/70B to be pretty flexible? It would be great to mount to the rack but after looking at it more closely there isn't a bar up there that doesn't contact ladders or material unfortunately. Maybe when I weld up my over landing rack I'll mount it up there. I'm going to go with that fender bracket you recommended and see how it goes. There is also the the Comet SS-680SBNMO that is dual band as well but has a spring base that might help with tree branches and the like. So many options out there I guess I'll just have to pull the trigger on one of them. Thanks for the help.

 

[DaveInDenver]

The regular 1/2 wavelength 2/70 flexes through the whip fine but isn't what I would call /super/ flexible. But it does IMHO strike a decent balance between flexible enough not to break easily but not floppy on the highway. If you ask it to flex too much you'll probably break the base. They make a dual band called the 2/70SH that has a spring at the base and is overall shorter (both whip and base), but is a 1/4 wavelength on 2m.

I have both (I like Larsen antennas, they're tough and simple). But even the short one with the spring you won't want to hit everyday on a garage door, the spring is more in case you forget and drive into a mall parking garage or under a tree branch.

Yeah, you'll end up with a bunch of antennas. There is never the perfect one. Hams are like Goldilocks with antennas; this one doesn't have enough gain, this one is too whippy, this one is too long, this one is too stiff. That's why the NMO is perfect, you can swap them easily. You'll probably end up with at least two, a trail one and a daily one.

 

[BenMara]

www.k0bg.com is a great resource for anything related to mobile ham ops

 

[BigSwede]

I have the Comet 680 on my bullbar. Here is a pic but it is hard to see!