Equipment Requirements for Mobile Install

[Peter1154]

New ham looking into getting a dual-band mobile for my '05 4runner. As of now, I'm leaning toward the ICOM 2730a and Larsen nmo2/70b. Main question is do I need some sort of SWR meter/antenna analyzer to measure SWR before transmitting on a mobile install?

On another note, any suggestions of non-hole mounting methods? Unfortunately I am unable to drill the hole. I know there are pros and cons to each method, just looking for personal experiences or advice.

Thanks in advance.

 

[hill]

With 05 Four Runner being 19 years old I would just drill the hole in roof for the antenna. It won't effect the value of it at all amd sure it's not too high either

 

[mmckenna]

Usually the antennas are tuned pretty close out of the bag. As long as you install it properly, you'll probably find that the SWR is acceptable. But, it's a good idea to check it after install, just to rule out any issues. You don't need to spend money on an expensive meter or something like a nano-VNA for a one off installation with a commercially made antenna.

Permanent mount antenna will give you better performance. Non-drilled mounts can create issues with tuning, directionality, and performance. If drilling the hole is absolutely off the table, we'd need to know what your other options are.

If you have some sort of overlander type rack on the roof, there are mounts that can work with that, but not all mounts are good, and not all mounting locations are good. Plus, you have to deal with cable routing.

Many take the short cut route of doing a fender bracket. That allows easier(ish) cable routing through the firewall to the radio, but having the antenna too close to the cab can cause reflections. Offset mounting on the fender will make it directional. Also, having the coax too close to the engine bay/ignition can result in some issues.

Gotta pick your compromise, what's more important to you? Easy installation? Better performance? Low clearance? Your skill level?

 

[ladn]

New ham looking into getting a dual-band mobile for my '05 4runner. As of now, I'm leaning toward the ICOM 2730a and Larsen nmo2/70b. Main question is do I need some sort of SWR meter/antenna analyzer to measure SWR before transmitting on a mobile install?

On another note, any suggestions of non-hole mounting methods? Unfortunately I am unable to drill the hole. I know there are pros and cons to each method, just looking for personal experiences or advice.

Welcome to RR.

I have a 2730A in my 2018 4Runner. In town, I use an 18" VHF whip on an NMO mount. Out in the backcouontry I use the Larsen NMO 2/70.

You won't need an SWR meter or analyzer. The Larsen antenna is good to go from the factory for ham frequencies. It will also be fine for RX on any frequency within the range of the radio, but if you are planning on transmitting "elsewhere" on high power, you'll want to check the SWR as the NMO 2/70 has a somewhat narrow bandwidth. Also, if your Larsen has the open coil in the middle of the antenna, you might consider covering it using heat shrink tubing. The coil is a branch catcher!

If you haven't done so already, I strongly recommend purchasing the RT Systems programming software with cable.

 

[nokones]

A Lip NMO attached to the rear edge of your hood might fit your application. If you have a Roof Rack and depending on the style of that rack I may have another solution, but it will require that you run a cable up to the rack.

 

[GlobalNorth]

Does your LED lighting cause RF issues that close to your antenna?

 

[nokones]

Does your LED lighting cause RF issues that close to your antenna?

The lights with the amber lens covers are my Ditch Lights. I no longer use the Lip NMO mount depicted in the picture of my previous post and it was used with a C27 CB Antenna. I went back to my rear Firestik because I got better Farz with the Firestik. I never turned on the Ditch Lights when I was comparing the two CB antennae.

On the Driver's side, I have my VHF antenna in front of the Ditch Light and when they are on, the weak VHF signals are affected big-time.

 

[Peter1154]

Thank you for all the replies. I'll look into the other options as @mmckenna said and balance my priorities with the pros/cons. Thanks again.

 

[WSEM262]

I had really good luck with the Tram 1180 and Yaesu FTM200D dual bander.
At first the antenna was mounted on a hood lip NMO base and SWR was consistently 1.3 or less on 2 meter and 70cm bands.
Ive since "drilled the hole" in my roof and the SWR is now 1.00 to 1.01 @ 146.520 and 446.000.

This antenna is absolutely spot-on right out of the box. It will not play nice with MURS or GMRS frequencies though.

A good compromise if those freq's are needed... is the Comet 2x4SRNMO... but it will need a good roof-mounted ground plane to keep SWR happy.

I actually drilled two NMO holes in my roof. One in the center of my cab (2020 Tundra) and one in the truck cap with a 24x24 piece of sheetmetal under it to create the ground plane.
I use a Midland MXT26 6db gain GMRS antenna on the cab and the Tram 1180 in the cap for 2m/70cm. They are fed by two separate radios also.

 

[Peter1154]

Alright, I've done some research/consideration and think I have decided to put a nmo2/70b on a ditch light bracket. I know the shielding from the vehicle is not ideal, but I think it's the best option for me. Few questions for you all:
- will rf exposure be an issue with the antenna being near the passenger side?
- do you think this set up would give a decent-enough ground plane to use a 1/4 wave antenna like the 2/70sh?
- would you recommend getting a nanovna (e.g. the H model) before transmitting?

Thank you for the advice.