Tools for Off-Roading

[Luke42]

Well, first off, racks that are screwed into the body of the vehicle are fine for grounding.

Secondly, you can just screw the antenna directly into the mounting point, you don't have to hang it off a roof rack that adds more drag than your antenna.

The crossbars are the wrong shape.

The crossbar is a ---, not an X or a *.

A lot of people do hang antennas off the side of their car with fender and bumper mounts. This is distorts the radiation pattern when the antenna broadcasts, and it's probably fine for some applications.

The best place for an antenna is in the middle of a metal roof.

If the roofracks are easy to attach/remove, that may be the solution. I can add ground radials where they need to be, and attach it when I need it, and remove/disassemble it when I don't. But the devil is in the details of how it all goes together.

This is a solvable problem. But each solution comes with tradeoffs. I don't see an obvious winner for most use-cases the way there is for conventional cars (mag mounts and through-hole NMO).

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[Luke42]

The determining factor is line of sight father than EIRP in these cases. Expect 1 - 5 miles depending on terrain. For real range a repeater is needed. With a properly sited one you could get over 100 miles.

For air-band, simplex and omnidirectional antennas are standard. No repeaters, no directional antennas -- because these are moving vehicles which need to broadcast in all directions. Line-of-sight works in our favor a lot of the time.

For the air-band use-case, getting the basics right seems like the way to go.

For 2-meter HAM, that's a completely different story! The local repeater operators are open to whatever you've gotta do to hit t he repeater. Plus, the repeaters stay in one place!

 

[Crissa]

The crossbars are the wrong shape.

It's whatever shape you want it to be. The mounts are usually just screw points, aren't they?

And you ignored the idea of using the window itself. I don't know the radioreflective properties of the glass they're using, but it's probably more like metal than most. Put your loop there.

There are lots of solutions. The roof itself is a big box.

-Crissa

 

[ajdelange]

If you are familiar with aviation radio you should be familiar with the √(h1 + h2) rule based on sperical spreading and thus loss of 20 db per decade and the shape of the earth. This means, practically speaking, that it may be possible to talk to a controller 100 miles away from 10000 ft with a handie. OTHOH as soon as one of the stations goes beneath the horizon, behind a mountain or through heavy forrestation (especially in summer when the leaves are out) spreading is secondary and losses become 40 db/decade or more. I've had pretty extensive experience with low power radios in aviation, business, ham, FRS, military and other bands. With VHF/UHF in hilly woods expect the game to be pretty much over at a mile. This can go out to 2 miles or 3 or even more if the terrain is flat and treeless. Over water perhaps 5 miles (unless the antennas are on tall masts of ship, shore or both in which case you can communicate much farther).

Every dB is precious, of course, but if you are fighting 40 dB per decade picking up 1.25 dB by improving antenna VSWR from 3:1 to 1:1 is only going to buy you range improvement of 10^(1.25/40) = 1.075 which is 396 feet of additional range if you are at a mile with the 3:1 antenna.

Another thing to keep in mind is that the better modern radios can do automatic antenna matching so that even if your antenna groundplane isn't that great the radio can still match to it so that there is little return loss. Then there are other types of antenna like log spirals, sleeve dipoles, patch and so on. Hams were, when I was active, known for their ability to innovate. Perhaps that's no longer the case.

If you are using a handie to talk to an aircraft you should have no trouble as long as it is above the horizon and hills don't block LOS. If you are in the ham bands you should have no trouble talking to a repeater as long as there is LOS to it (doesn't mean you have to be able to see it - means you would have to be able to see it if the trees were gone).

Haven't thought much about this stuff in years but it only took me a minute to find this 2m "no ground plane" antenna: https://www.theantennafarm.com/catalog/laird-technologies-b1442n-752. Of course you still have to mount it somehow and get a cable to it. I wouldn't want to be drilling holes in my CT but you can't make an omelet without breaking eggs.

 

[ldjessee]

I saw someone make their own ground plane using roof rack bars by having a piece of sheetmetal between the bars with the antenna mounted to this piece of sheetmetal. Attention was paid to make sure the sheetmetal was grounded to the vehicle body (common ground).

I was not worried about these details, my plan was to check to see if the bed of the CyberTruck was magnetic and just use a magnetic mount there, if not, then use the rail in the bed to mount the antenna for mobile setup.

I have also seen interesting bumper mounted fiberglass poles that have antennas attached to the end, which gives a huge elevation above the vehicle (it was on a Jeep).

I have seen some interesting tripod dismount antennas as well that if I really got into Ham I would consider doing more research.

I have not done much with radio other than some simple research when I thought I was getting a Jeep Gladiator (now I have a CyberTruck reservation) since I got out of the Army. I did consider doing a Raspberry Pi with Ham doing packet radio, but decided to focus on a hobby I already had instead of getting into another one.

 

[FullyGrounded]

I've been watching some YT videos to see what different people's off-roading experience is like. Some that I'm liking are from The Story Till Now. Conveniently those guys are up in British Columbia so they have somewhat similar terrain as what I'd expect to get around here in Washington State.

Watching the videos though I'm noticing that there are a number of regular use tools that I'll probably want to get with my CT in order to make these trips. The powered tools I'd like to be either battery-electric or plugin with extension cords if necessary. But some of the things I'm seeing as necessary are:

• Some Jacking solution

Anybody have any other favorite tools that they like when off-roading? Any recommendations?

Yes, a high-lift jack is an off-road staple. Don't be shocked if you see someone having one mounted to their hood. Just sayin. peace

 

[Crissa]

Yes, a high-lift jack is an off-road staple. Don't be shocked if you see someone having one mounted to their hood. Just sayin. peace

That's a terrible place for one. The sail is a better place; it wouldn't hit your range as much.

-Crissa

 

[FullyGrounded]

That's a terrible place for one. The sail is a better place; it wouldn't hit your range as much.

-Crissa

We will see. People love to show off their gear. haha

 

[ldjessee]

That's a terrible place for one. The sail is a better place; it wouldn't hit your range as much.

-Crissa

I was thinking along one side mounted to the rail if it does not fit inside the sail pillar storage.

I also cannot suggest high enough having a shovel, ax, strap, and some kind of traction/weight distribution device (ie, MaxTrax).

Then would be a winch, even more recovery tools (like snatch blocks, tree protectors, chains, etc), and a fire extinguisher.

 

[Crissa]

Yeah, I was thinking along the top of the sail, in that backpack roof rack area.

-Crissa

 

[Ehninger1212]

Yeah, I was thinking along the top of the sail, in that backpack roof rack area.

-Crissa

I'll just throw mine in the bed/"vault".

 

[Sirfun]

I'll just throw mine in the bed/"vault".

Don't you guys think if Elon says you could mount a Giant Paintball gun in the bed. That you could mount a jack? I don't want a jack sliding around in the bed of my truck! Maybe mounted to the accessory rails on the inside of the bed?

 

[Crissa]

Maybe mounted to the accessory rails on the inside of the bed?

That seems like a good idea. Right now I have velcro on my trunk things so they don't move around.

-Crissa

 

[ldjessee]

I looked up a bunch of mounting gear for L-track and T-slots early in the year (Jan-Feb), but cannot find those notes now...
Found this quickly, hilift mount.
https://www.gziladesigns.com/products/jack-tool-mount

 

[Ehninger1212]

Don't you guys think if Elon says you could mount a Giant Paintball gun in the bed. That you could mount a jack? I don't want a jack sliding around in the bed of my truck! Maybe mounted to the accessory rails on the inside of the bed?

Yeah.. but im a cheapskate.