Mobile setup - Radio, or mount?

[K9CCH]

I'm installing my FT2800M today, and it will be connected to my 40" dual band antenna which is on the hood of my Jeep.

The antenna mount, a Diamond K400S, is on the drivers side of the hood, and has a 13.5' coaxial cable. I've ran the coax through the firewall on the drives side, and down through the dash. It comes out under the steering wheel.

I will not be needing all 13.5 feet of the coax, so I need to coil a little either at the radio side, or the antenna side. Which is better?

If I'm recalling my studying correctly, I should coil the extra near the antenna mount so that it acts like a balun preventing the waves from returning back to the radio... correct?

[NQ6U]

It really shouldn't matter much in this case. On my truck, the extra coax is just laying behind the seat in a random heap and it seems to work fine. If you do want to make it function as a choke balun, you'd need to wind it solenoid fashion—that is, in a helix.

[K9CCH]

In a what? LOL

[PA5COR]

Make a neat coil not overlapping to each other, use a small bottle to wind the windings next to each other.

[K7SGJ]

I have my control panel on the dash, and the radio under the rear seat. The excess coax is just kinda bundled up there, like Carl was saying. I've looked at the SWR with the cable stretched out, bundled, coiled, and I could se no difference on an analog meter. Maybe a digital would show some slight change, but it wouldn't be much. Besides, when you are tooling down the highway, the antenna is constantly moving around changing everything anyway. If you had a couple hundred feet of excess, that would be one thing, but a few feet? Pfffft. Just chuck it outta the way and have fun with the radio.

[NQ6U]

In a what? LOL

Kids these days, I'm tellin' ya...



For illustration purposes only, ignore the text.

[K9CCH]

OOOHHHH..

Well I got it installed. I just don't know where I want to mount it yet, or how. I'm not a fan of drilling into my Jeep, and I want to keep things as clean as possible. Right now I'm leaning towards putting it on the passenger side of the console, next to the shift, but that requires that I drill holes in the plastic. And I need to figure out how to disguise those holes if I ever take it out.

[WØTKX]

That's like, helical, man. And no, it's not going to make any difference here. Just wrap it up and stuff it away under the dash.

Coax baluns are more useful for messing with antennas with a tuner, or other situations where you may get RF on the shield.

Typically on the lower frequency bands. And coax kinda sucks in those scenarios anyway, so ladder line is better.

[K9CCH]

Just fyi.... when soldering wires that are still connected to the battery, DO NOT allow soldering gun to touch both red and black at the same time. OOPS! Thank heavens for fuses!!!

But its working. I have simplex, and my two favorite repeaters programmed already. There's some fuzz in it, so I'm thinking I'm getting interference from somewhere. If I put the radio up on the dash, just above my DVD/Radio it's really staticky. If I put it down on the seat it gets a little quieter. This is where its going to sit for the time being until I a.) find a better place for it, b.) decide to drill holes in my Jeep, or c.)decide to actually clean up the installation.

[NQ6U]

That's like, helical, man.

Helical on wheels, man.

Chris, that noise you're hearing is, unfortunately, pretty common in modern cars with all their electronical gagetry. Didn't have that problem in my '52 Dodge. Didn't have ABS or airbags or disc brakes or independent suspension or even turn signals either but it was very quiet, electrically speaking. One thing that might help is running a separate ground wire from the case to the body of your Jeep.