A GMRS Radio over a CB Radio???

Are you a driver? Have you not seen what Cascadia mirrors look like?

The answer to your question: They won't work because the mirrors on a Cascadia aren't tubular bars like on Volvos and Kenworths. They are larger in shape and made of plastic. All of the mounts you linked to are designed to clamp onto tubular-style mirrors.

See Craig's post showing an example of an antenna mounted to the driver's side mirror using the ProComm mount: 7-foot Firestik with Tunable Tip

The ProComm mount I use and intended to use on the passenger side replaces two of the four screws that hold the mirror in place with longer bolts and spacers.

Having said ALL of this, I just today realized that I had forgotten that I was saving up for a WeBoost OTR cell booster and I plan to place the external antenna of that system on my passenger side. So, in the end, my GMRS antenna can't be mirror mounted after all. I need to find somewhere else to mount it. But where? I have no idea.

 

Ah sheeit. I just realized that the second thing you linked to was a bird perch and not an extension. I guess I can't read. My bad!!

Yeah, I guess that would work. Just not sure how the GMRS antenna would interact with being so close to my CB antenna or my cell boost antenna (when I get it).

 

CB radio is perfectly adequate for most mobiles, so why invest in another transceiver that radio communications equipment manufacturers want to sell you?

UHF GMRS will remain low power without the established repeater infrastructure necessary to increase range.

How many know that the predecessor to GMRS was named Class A Citizens Radio Service and began back in the 1960s. It was supposed to eventually replace 27 MHz but it never panned out that way due to interference caused by overcrowding, not to mention scofflaws refusing to purchase the required licenses. As usual, human nature ruined that initial plan--just as it did with 27 MHz CB when it too became overcrowded and was subject to interfering skip conditions and hobby use.

See: General Mobile Radio Service - Wikipedia

Australia and New Zealand, however, were smart in that they specifically established a 40- channel UHF CB band (476-477 MHz) in 1982 with specific channels linked to repeaters, thereby increasing range. This service has proven to be so popular--particularly with truckers--that it was recently upgraded to 80 channels. UHF CB there was initially created to replace their existing 26-27 MHz CB band but that never happened. 26-27 MHz usage there, however, has significantly decreased but is still legal and used mostly by hobbyists talking local and shooting skip when propagation conditions permit.

Having often visited both of those "down under" countries, I can report that after monitoring their UHF CB service on my portable scanner, they've got a pretty reliable system in place. Troublemakers (called ratbags) and/or drunks who attempt to "hold forth" or interfere over a repeater are quickly dealt with by temporarily shutting down the affected repeater until the trouble stops. Subsequently, what I monitored on a daily basis were truckers going about their business as well as in contact with their dispatchers. I heard very few ratbags.

The fact that the original Class A Citizens Band Service failed in the U.S.A. comes down to behaviour--or the lack of same.

In any event, there are plenty of existing VHF channels in North America assigned to the trucking industry and plenty of relevant VHF equipment to go around.

 

No reason for most to run GMRS, without a repeater why would you want to. And by the way I don't believe that the GMRS repeaters link up like HAM, Did not back when I had a Motorola Shop. A group of local or regional drivers that want dependable comm, switch over to Moto digital.

 

I'm brand new to this Forum, but I've been into 2-way radio my entire life. Here's my take on the GMRS vs. CB debate.

Pros and Cons:

GMRS: Pro -- you can legally run 50 watts Con: 400 Mhz UHF has much shorter range
Pro -- Shorter antennas
Pro -- Repeaters Con: Most GMRS Repeaters require the owner's permission to use.
Pro -- FM less static interference Con: Shorter range communication
Pro -- Requires a license so less idiots broadcasting Con: Can't modify equipment for better range.

Citizens Band (CB): Big Pro -- Virtually unregulated by FCC. Con: Can cause lots of harmful RF interference.
Pro -- Lots of illegal mods available Con: expensive.
Pro -- Much greater range Con: Lots of skip interfering with long range communication.
Pro -- Can be modified to transmit outside of band Con: Don't get caught.
BIG Pro -- Single-Side Band (SSB) Con: Much more expensive equipment.

So what's my take on all this? Stick with CB. In a moving vehicle it's almost impossible you'd ever get caught for breaking the rules. In times of skip, you can move outside the regular 40 channels to talk local as long as your buddy also can go there. You don't need any kind of license, so once you purchase your equipment it's totally FREE communication.

If you get an Export CB radio, they usually will put out close to 100 watts and if you go with SSB, you can easily talk 50 miles or more Simplex (no repeater).

As for the fiberglass truck body issue....I don't own a big rig, but I can't believe they are all fiberglass. They have to have some metal underneath to support the structure in case of a roll-over, etc. Buy a Roof Mount antenna and drill through your roof. As long as part of the antenna's base is in contact with the metal you have a ground plane.

 

Big trks have a ton of fibreglass...
Hood is fg,i think half way up the bunk walls is fg and so is roof..
Without out a super good tech and really good ant set up 50 mi is pushin it..Barefoot on todays trucks but from trucks with more metal yeah i would almost expect that range..
There is always the exception to..

 

There's got to be something supporting all that fiberglass underneath even if it's just a metal cage or roll bar. That's what you'd need to drill into to get your ground plane.

 

Dont need to drill for gp..Bonding is the key and where its mounted..
If you look for it im sure there a build vids of all these trucks...
Im pretty sure that a roll cage is not a factory item in any truck....After market,sure..