Clean VHF/CB radio installs

The FCC issues a license to persons or organizations that have a legitimate need to transmit from land. Such as marinas, harbormasters, Bridges, etc. Generally this license only applies to one channel. The USCG is different situation. They are bonafide for other reasons.

Keep in mind that a great deal of recreational boaters also require a ship station license. For example, if you communicate with a foreign Port, a ship station license is required. Which pretty much covers everyone on 4 of the 5 great lakes. Anyone near the Bahamas or Mexico as well. The vast majority of recreational boaters are exempt and don't require any license.

There is a great deal of Marine band use for radio communications on land. It's very illegal. On the wrong channels, it's outright dangerous. In some cases, some of the marine band channels have been licensed to the part 90 band inland. So you may be causing harmful interference to police and fire. If you want to use VHF, stick with MURS, get a commercial license, or get your ham license.

In my view using a radio improperly is just as egregious as throwing a bag of fast food trash out your window.

 

The use of a VHF marine radio on land is one of the most common mistakes boaters make. This even includes the use of handheld radios walking around which I see people using all the time on land without having a clue that they too are illegal without the proper licensing.

You no longer need a license to operate a marine radio on a recreational private vessel, so people assume that you can operate it without a license. Once you are no longer afloat (or in a foreign port) you need both Ship’s Station license AND a Marine Utility license and show need for it. Even with proper licensing there is also a legal distance inland you can operate (I think 3 miles).

I lived in a marina for a long time and got used to monitoring distress Ch16 as a habit. I filed for all of my licenses years ago and have kept them renewed because they have gotten harder to get and cost real money to keep renewed. To be legal transmitting to answer a distress call, I could use the radio on my boat in the slip using my shipboard station license, or from my handheld if I was ashore in the condo. Never a fixed, full power radio from land. One of the tenants here was fined $10,000 for doing so inside his home a few years ago. The FCC has gotten very good at pinpointing transmissions which is a good thing for public safety, but it is hell on illegal transmissions. These days they WILL find you.

https://www.fcc.gov/wireless/bureau-divisions/mobility-division/ship-radio-stations
Using Hand-Held Marine VHF Radios on Land
You must have a special license, called a marine utility station license, in addition to a ship station license, to operate a hand-held marine radio from land -- a ship station license IS NOT sufficient. You may apply for this license by filing FCC Forms 159 and 601 with the FCC. To be eligible for a marine utility station license, you must generally provide some sort of service to ships or have control over a bridge or waterway. Additionally, you must show a need to communicate using hand-held portable equipment from both a ship and from coast locations. Each unit must be capable of operation while being hand-carried by an individual. The station operates under the rules applicable to ship stations when the unit is aboard a ship, and under the rules applicable to private coast stations when the unit is on land.

 

Thanks
Didn't realize it was a Marine radio.

 

Here's what I'm planning on installing for a simple CB setup:

Cobra 75

$20 Uniden (BC7) Bearcat 7-Watt External Communications Speaker. Durable Rugged Design, Perfect for Amplifying Uniden Scanners, CB Radios, and Other Communications Receivers.,Black

Uniden 7 speaker

Victory antenna mount

PCTEL NMO mount

Larsen NMO27B antenna

$8 Tram 1290 Rain Cap

Tram rain cap

Please let me know if you have any comments/suggestions. Thanks!

 

The NMO you linked is for thick bodies. Like an ambulance box. It might work in a camper shell. But a camper shell is fiberglass. So there's no ground plane for a 1/4 wave. If you're drilling your cab roof get a standard NMO.

$19 Laird Technologies - 3/4" Brass Mt,Cable,no cn

https://www.amazon.com/dp/B0079528XG/ref=cm_sw_r_cp_apa_i_312JDb4RSF1TA

How tall is that antenna. With that large of an antenna, you might consider a more robust NMO. Such as the breedlove #503.

https://www.breedlovemounts.com/nmo-roof-mount.html

Highway Patrol in my state uses the Laird NMO I linked above for their CB whips. They seem to hold up OK. But they're also on the highway. Generally not hitting any low branches on a trail.

 

Thanks for the suggestions!

For the antenna mount, I have the Victory 4X4 hood mount from here


And because it's .19" thick aluminum, I'm supposed to use a thick mount NMO, and that's why I chose the

$33 Pctel A/S - 3/4" Hole Thick Roof Mount Antenna

PCTEL.

Details on the Larsen whip can be found here. It's 52.5" tall. I have a cab-over camper that is pretty tall, and I'd like the antenna location to work with or without the camper for dual purpose. Pictures of the camper are here. I'll see how it goes. For 1/4 mile trail communication, I'm sure it will work fine...

 

.

 

I missed the victory mount in your first post. My bad. Sounds like you got the right stuff.

 

Attached is a template for the antenna hood mount should anyone want to fabricate one. I had to make one out of steel because my XM antenna didn't work with the aluminum one. Prints on Letter size (do not scale).

 

If you're doing NMO on hood why not just skip extra stuff and put one thing on - trunk lip NMO mount (shown with 1/4 wave VHF)? $20 for the mount w/18' coax w/

$38 PL259 USA Made PL-259 Improved Double Shielded RG-58u for FireStik Antenna K-8A 18-Foot Single CB/Ham Coax Cable

PL259.

 

Great idea! Trunk mount

$35 New Tram Browning Black 1246-B Trunk Antenna Mount NMO With PL-259 connector and 17Ft of RG-58 Coax Cable

here

I guess I'm trying to keep it hidden below the hood, in the gutter. Most of the time it will be covered by a rain cap. That, and I have a 52" CB whip, so I'll need an extra strong mount.

 

Is anyone concerned about RF exposure with those hood mounts? Especially the ones on the driver's side? It is a nice convenient place to mount but I've always been weary.

 

I am, especially when pushing 50W. I mounted my antenna on the roof; home made 3rd brake light mount, specifically.

 

I did the same, with the Meso 3rd brake light.

 

One for the CB



One for the XM


Now all I need is the cable mount and whip to show up!

 

Gives a nice “tingle” down below through the firewall for those of us without the skewp.
Good point...it is important to truly learn and remind ourselves of how rf works at what power and distance. I’m not a worry wort, but I do keep my transmission lines and antennas on the passenger side.

 

Legal power (5w) CB doesn't scare me at all. 50w of VHF is probably not ok. Although I've not done the math, I wouldn't consider a hood mount. That's pushing to much RF into your face, at a frequency where our bodies naturally resonate.

 

Yeah, I'm with ya on the RF exposure stuff on the hood-hinge mounts (and why stop at 50W in VHF/UHF?)

This calculator can be pretty enlightening when evaluating any kinda mounting location like that http://hintlink.com/power_density.htm (For reference, unless you're planning on not sitting behind the wheel while using your radio, your location within the cab should be considered and uncontrolled environment, since you won't be vacating the area while you transmit).


TLDR: Calculate --> http://hintlink.com/power_density.htm For space you can't leave during TX, with a isotropic radiator @ 50w at the feedpoint, you'll want to be more than 8ft away for 2m (~7ft for 70cm); both of those bands are more palatable at 10w (like 3ft or so), but antenna gain and feed loss will change the data. For the 11m CB stuff @4w 2 ft is fine for exposure in an uncontrolled space.

(a few tags for folks with similar questions that may find this helpful = @k8md ; @Cudgel ; @vssman)​

 

This is reassuring. Thank you.

 

Meh I'm not worried about a hood antenna leeching radiation into my head. Christ, I already have a cell phone to my ear, use a handheld radio with the antenna 2" from my face, not to mention all the ricky ticky bad shit floating around that we have no idea about... plus I hardly ever speak on the radio, I just listen... and when I do use the radio it's always on low power since we're within 1/2 mile of other trail partners.

I guess if you talk on your radio 12 hours a day and have it on 60W then maybe you could be concerned, but I bet dollars to donuts you'll still die of something else first...