GMRS antennas

WHOA there's a lot of antenna mount/wire options.
So now that I'm committing to PL-259 termination, still some options to figure out.
I saw midland's bundle kit uses a FME female connection with a FME male to PL259 male adapter.
this makes sense to help with passing the wire end through tight spaces and the firewall.
I might try to replicate this idea, unless someone tells me to just buy the Midland one and not worry about other brand name things....

17ft or so seems to be the average shorter length cable option. I assume similar to CBs, arbitrarily shortening this is a bad idea?

Summarizing my current finding options: (prices are just list prices, not including shipping/etc)

for options that terminate in FME connectors
Option 1) Larsen NMOKHFUD: 17ft, $24.95 for either male or female FME, 0-6000MHz, Brass, RG-58 dual shield
Option 2) Larsen NMOKHFUDFME: 17ft, $18.95, FME Female, 0-6000MHz, Brass, RG-58 dual shield
Option 3) PCTEL Maxrad MLFML195-NC, 17ft, $26.95, FME male or female, 0-6000MHz, Brass, ProFlex Plus 195
Option 4) Laird Technologies MABT8, 17 ft, $26.95, FME male or female, 0-1000MHz, Brass, RG58/U
Option 5) PCTEL Maxrad BMA-NC, 17ft, $26.95, FME male or female, 0-1000MHz, Brass, RG58/U
Option 6) Laird Technologies MABVT8, 17ft, $29.95, FME male or female, 0-1000MHz, Brass, RG58A/U

with generic FME to PL259 adapters on Amazon around $5-$10

so questions for you smarter/more experienced people.

Q1) aside from literally the hole size, is there a performance difference between 3/4"NMO vs 3/8" NMO?
Q2) cable list frequencies, do I want a smaller window around 465MHZ like 0-1000, or is wider better like 0-6000?
Q3) Is there a preference/superiority on the cable types between RG-58, RG58/U, RG58A/U, RG-58 dual shield, Proflex Plus 195, etc?

Thanks





Options below I started listing, these are straight to PL-259 connector, keeping it here just because i made the list, but probably not going this direction.
Option A) Laird MB8PI: $22.95
Material Brass
Frequency 0-1000 MHz
Connector PL-259 Connector Installed
Cable Type RG58/U
Cable Length 17 feet
Option B) Larsen NMOKHFUDPLI: $24.95
Material Brass
Frequency 0-2500 MHz
Connector PL-259 Connector Installed
Cable Type RG58/U
Cable Length 17 feet
Option C) PCTEL Maxrad NMO58UCPI: $24.95
Material Brass
Frequency 0-1000 MHz
Connector PL-259 Connector Installed
Cable Type RG58/U
Cable Length 17 feet
Option D) Larsen NMOK: $22.95
Material Brass
Frequency 0-1000 MHz
Connector PL-259 (UHF Male) Connector Loose Uninstalled
Cable Type RG58/U
Cable Length 17 feet

 

Do you really want to drill? I used trunk lip mount NMO’s and ran the cable through the firewall and then terminated the coax after it was in the cabin.

https://www.theantennafarm.com/catalog/index.php?main_page=product_info&cPath=264_267&products_id=1171

Any RG-58 works good with GMRS for the distance you will be running.

Also if you have excess cable, it is better to run it around vice coiling it up.

 

I'm just welding on a tab on the front bumper hoop for the antenna so drilling either a 3/8" or 3/4" hole is no problem at all.

is terminating the coax on a PL-259 just a matter of a crimp to the outside and a solder to the core? If that's all there is and nothing special I can handle that

 

I’ve always just gone with a 3/4. I’m not sure there really is a performance difference.

Different pl259s go on different ways. There are the crimp on type, and there are some screw on types that sort of just wedge against the outer braid on the coax. I like the crimp on type. You can buy those on Amazon as well as a cheap tool to do it. A quick YouTube video and your ready to go.

I usually end up running only as much cable as I need to my radio, cutting off the excess then crimping on a

$43 pl259 USA made PL-259 improved double shielded rg-58u for firestik antenna K-8A 18-foot single cb/ham coax cable

pl259 and soldering the tip for continuity.

I’ve run various cable types...lmr240, rg8x, rg58. For short runs on a mobile your cable doesn’t really need to be anything special.

 

How about these?

https://antennas.alamosa.mobi/

 

They have the Aussie look but you could have probably same if not better performance from a much cheaper traditional antenna from Laird/Pctel/Maxrad/Larsen that maintains a slim profile.

edit: they are also too robust to mount anywhere except something like a plate bumper for which they were originally designed. Hit a tree limb with that thing and it’s going to rip your sheet metal apart.

 

haha yup, Ive been down this rabbit hole before trying to do what you are doing on the front bar. Still using my little stubby one on an NMO lip mount on the hood for now. No issues with that other than its starting to rust which I assume is probably not great for signal.

Anyway long story short Im following along to see what you find.

Those look cool, but damn are they expensive

 

There is nothing special about GMRS antennas no magic they all work exactly the same. They have a frequency range that is the variable most are adjustable by length, generally the whip is to long for the band so it can be cut to tune or able to cover the range it was intended for by design. They make brackets that fasten to the bolts in the fender that the hood will close over. A 1/2 wave does not need much of a ground plane. There are numerous antenna manufactures to chose from don't buy a no name more than any thing else they are cheaply made they will work on the band intended like I said no magic but won't hold up in the weather or vibration, Dimond makes a very good mobile antenna for one. GMRS is a licensed band you'll need one no test just fill in the blanks.

 

You should have seen my Tarheels HF screwdriver antenna offset mounted the the front hitch on my old 3/4 Suburban. I had to mount it there due to the platform I had on the rear for all the stuff we were taking on vacation to the Outer Banks with the kids. That antenna was definitely not tree safe (in this case the antenna would take out branches).

 

I still have an older Tarheel It is my camper antenna (not for mobile use!). The Tacoma has a little Tarheel (6 to 80) it is mounted to the pillar at the tailgate inside the bed that was after the 3/8 24 coupler incident, snap in half and the antenna fell in the street thankfully a friend was following me and picked it up. Note to self don't buy MFJ couplers any more cast cheap brass with shiny chrome look.

 

Looks like soldering is pretty straight forwards and don't need a special crimper.
shopping list looks like this
Laird Technologies BB4502N $34.95
PCTEL SMC-NC $17.95
Larsen PL259 $3.95
with a $9.64 shipping
to total $60.80

doesnt seem too bad, unless someone sees any reason I shouldnt go with this selection, I might be done researching. thanks for all your help!

 

How are you going to mount it through the bracket with that setup?

 

I'll drill a 3/4" hole in a 1/8" thick 1.5" wide flat stainless bar I'm welding to the front bumper hoop.

from the datasheet here it looks like
"NMO Style Mounts - Stainless Steel “SM” Series 3/4” hole; 1-1/8”-18 thread; installs from above; can be used for metal thickness to 0.46”"
so .125" thick plate should be good

Am I missing something?

 

Oh ok so I guess the larger outside threads must screw on/off from smaller threads in the center.

 

Yes the NMO will work on any thing metal you can bore a hole in. 1/2 wave doesn't need a ground plane but the antenna needs to be grounded the ring on the NMO is the ground so it has to be tight and clean. The base of the NMO has a "T" shaped part with small "teeth" on it the 3/4" hole is important it just fits.

 

Yup, the clean ground is the reason I'm going with stainless so I can keep it raw metal without worrying about corrosion.
I'll add a ground stud to the bumper to tie to a frame ground too.

 

You can it won't hurt a thing but the vehicles of today are pretty will grounded and at 462 megs and 50 watts it's not much of an issue. The bigger issues come in the HF bands.

 

it’s not really the NMO piece itself where you have to worry about corrosion. The exposed coax and where it mates to the NMO is the issue. Most are not weatherproofed or sealed assemblies so you will have to figure out how to keep water out otherwise your coax will corrode.

 

Quality NMO's have a plastic cover and heat shrink at the end of the coax. Most installs are in the roof and the brass nut is "O" ringed so they don't leak. NMO's (New Motorola) have been around for decades some newer one are rated to 6000 Megs. Biggest issues I have see is with dissimilar metals at the actually mounting like brass and aluminum.

 

good point on the coax protection. I have plenty of adhesive lined heat shrink but without having the parts in hand im not sure heat shrink alone is going to seal the whole connection.
I'll keep it in mind when I receive the parts.

(the stainless I was talking about was the bracket on the bumper)