Mobile Antenna Mount

[Jim1348]

The last time I bought a mobile antenna mount it was for VHF/UHF. I am now more concerned with 800 mHz. Do most antenna mounts use the same coaxial cable nowadays (RG-58U perhaps) or are the manufacturers making mobile antenna mounts with lower loss cable for the higher frequencies now? I realize that the short length I am talking about here is only somewhere between 12 and 17 feet, but I am just curious.

[mmckenna]

I've been using RG-58 dual shield on my stuff. It tends to have slightly less loss. Same connectors as the regular stuff.

We have about 40 800MHz mobiles installed on various things at work, and they are all using this. It'll work just fine. You can often find either the LMR200 or LMR240 (can't remember exactly) and it's a bit better at higher frequencies, but it's stiff cable and not as much fun to run in a vehicle.

[Jim202]

I've been using RG-58 dual shield on my stuff. It tends to have slightly less loss. Same connectors as the regular stuff.

We have about 40 800MHz mobiles installed on various things at work, and they are all using this. It'll work just fine. You can often find either the LMR200 or LMR240 (can't remember exactly) and it's a bit better at higher frequencies, but it's stiff cable and not as much fun to run in a vehicle.

One point to make here is that RG-58 is not double shielded. There are other cables that do have double shielding, but are slightly larger in Outside Diameter. The crimp shells for the normal RG-58 cable will not normally fit the double shielded coax cable.

Jim

[mmckenna]

Interesting. I've been purchasing the Larsen NMO mounts with dual shield RG58 and have had no issues at all installing mini-UHF connectors designed for standard RG-58. Maybe we are talking about two different things. The Larsen mounts appear to have a foil shield under the outer conductor and it doesn't interfere with any of the standard RG-58 connectors I've installed.

[Bill_G]

I've been round and round on this subject before. Unless your mobile cable is damaged in some way, exactly how much real world performance difference do you get by shaving a few parts of a db out of your losses? To me it's one of those pointless exercises.

Case and point - Large national school bus service wants every bus touched, programmed, replaced, repaired, upgraded, etc in preparation for the narrowbanding deadline. Okay. Worthy cause. There has obviously been little or no maintenance for years. Part of the contract requirement is every single coax cable has to be replaced, and a new antenna installed. Okay. Will comply. Net effect - none. No range lost, no range gained. They still cannot cover their respective districts. We could not in good conscience leave the ground wires with the three butt splices in place. Neither could we not do something about the bracket bolted to a broken cup holder, the speaker wire to no where, nor the green fuse holder. But, even after it was all tightened up and brightened up, it still didn't work.

[mmckenna]

Absolutely 100% true. You likely won't notice a difference.

However, if you are buying new and the price difference is minimal, it does't hurt at all.

[KE7JFF]

My rule of thumb is that if your antenna is lets say 20 feet behind you in something like a RV, then you might want to spring for RG-8X. If its for your average sedan or SUV, RG58 for 800 is just fine.