Radio setup reccomendations for crossing Africa

[Rich.]

Im currently building up my truck for a few month trip to Africa. I will be doing it solo, across a lot of the Sahara, so im looking at a good radio setup (as well as carrying a sat phone). But having not done much with radio's before (planning on doing my licence before the end of the year) im a bit stuck on my setup.

So, i'd like UHF, VHF, HF and to keep my CB, for group chatting.

Im looking at the Icom 7100 radio, seems to be well liked and a good package for all 3 bands.

Where i start to get stuck is Antenna's, and their placement. So, i have an ARB delux bar on the front of my Navara, and i want to mount the 2m/70m dual band on one of the antenna mounts, and the HF on the other. So the first question is, will that be enough spacing between the two?

I know the ARB is a pretty bad location ground plane wise but its the only place i've got thats viable, so i need to make the most of it. Reading into the UHf/VHf antenna's and lack of ground planes, im finding it very hard to find out which antennas do and dont need a ground plane. I have read a few times that 1/2 wave antennas work better with no ground plane, but im struggling to find any for sale in the UK. Basically im looking for the longest range possible, with a length around 1-1.5m, does anyone have any good suggestions? The Diamond SG-7900 is my top contender, but theres conflicting info on the web as to wether it needs a ground plane or not.

Next is the HF, im looking at the little tarheel II motorised antenna, from looking at placements of this, and the fact thats its an HF band antenna, im guessing this will be fine on the ARB without the ground plane?

The auto tuner i was looking at to go with both the little tarheel and the 7100 was the Icom AT-180, but its pretty steep! Does anyone else have a good reccomendation for this?

Finally, not so much about setup but about using the gear. The 7100 only allows you to work/listen to one band at a time. For crossing somewhere like Africa, with the option of VHf/UHf/HF, would the preference be to leave the radio on the HF calling channel?

Thanks for putting up with my probably very basic questions!

Rich

 

[doug720]

I'm no expert in radio communications in any way, but I have a VHF in my LandCruiser with the antenna mounted to ARB front bumper.

The unit is a ICOM V8000 and the antenna is a non-ground plane type. I have used my radio at many off road events where I act as radio relay. I have never had any complaints about the transmission or had problems receiving. The check points at these events are often 20-40 miles apart with hills and valleys between them. In addition, I have spoken and heard other radio users up to 130 miles apart in the same conditions.

A non-ground plane antenna has worked well for me.

In addition, the front bumper location is much better for trees, heavy brush, buildings and wires, and does not interfere with roof racks and loads.

I don't recall the name and model off hand, but will post it.

Doug

 

[Frdmskr]

Given the environment consider commercial gear to handle the heat. More importantly I'd ping Andrew Saint Pierre White on his 4xForum webpage or via his Facebook group. He or someone on his Facebook group can help. Several Middle Eastern over lands pop in there.


Sent from my iPhone using Tapatalk

 

[gary in ohio]

What are you comm needs? WHo and how far do you need to talk? Since your going to have multi governments in the loop you should contact local 4x4 groups to find out what is legal and tolerated in various areas.

 

[PhulesAU]

And you may need to be licensed in all countries you'll be operating in. I'll throw in my vote for a SCG coupler, and a simple 10 foot whip.

 

[ghutch]

Read some here....best website for mobile installations....www.k0bg.com
Covers all areas, safety wiring, antennas, HF V-UHF, good luck!

 

[Hillbilly Heaven]

Ok I am going to throw my 2 cents in.

HF go with a Hi-Q antenna something like his ruggedized 5 or 6 series. These are military quality antennas. Highly rated. Check out the antenna reviews on eham.net One nice feature that sets it apart from other screwdriver style antennas is the length is constant over the tunning range. Most screwdriver antennas like the Tarheel change height as you change frequency. If using a Hi-Q, Tarheel, or any other screwdriver antenna you don't need a tuner.

VHF/UHF The Diamond 7900 is an excellent antenna. If you have roof space or even a roof rack you are better off mounting any vhf/UHF antenna there. Even if you do mount it out on the ARB make sure the mount is grounded. Any antenna should work there but will be highly directional out the front. If the roof area is a no go consider moving up on the fender near the A pillar.

Only time you need to worry about a ground plane is if the vehicle or camper body was fiberglass or not contain a conductive material. Don't put a lot of thought or worry about ground plane. Worry more about placement so that the signal will be uniform in directional strength.

BTW HF antennas are less sensitive to vehicle location than vhf/UHF antennas because of the longer wave length.

 

[Rich.]

Thanks for all the help guys.

The more i think about it, the more i think im going OTT. The main reason i wanted HF was for emergency contact when im in the middle of no where. Regularly i will only be using UHF,VHF and Cb. This is leading me to think i might be better off with a deployable mobile HF antenna, instead of a vehicle mounted one.

Hillbilly, your point about ground planes is pretty much what i though, but the more reading i do, the more people are saying that groundplane has nothing to do with conductivity of what the antenna is attached to, but that it needs a flat metal area under the antenna, like a roof or a bonnet. Any truth in that? Direction is another problem i did read about, will the lower bumper mounting affect it that much? Why would mounting near the A-pillar be better than the ARB?

Thanks again

Rich

 

[Hillbilly Heaven]

Difference in mounting it on the ARB versus near the A pillar is the directivity of the signal. On the ARB the majority of the signal is going to be directly in front of the vehicle. Moving it back some is going to give you more off to the side.

Easy way to picture the signal direction is to draw a rectangle that represents the vehicle. Draw two diagonals. Where those two diagonals cross represents the center of the vehicle. An antenna mounted there will give the most uniform signal. You could draw a large circle if you wanted to. Now move that antenna anywhere on the vehicle. Maximum signal strength will be 180 degrees opposite of the direction you moved the mounting point.


Conductivity and ground plane: For an example my vehicle has a fiberglass roof and side. Inside this fiberglass is embedded steel for reinforcement. I can mount any antenna on the roof I want to, but for the steel to act like a ground plane I would need to make sure that the antenna ground is also connected to the steel inside the fiberglass. It would then behave just the same as a steel bonnet or roof.

 

[Rando]

Maybe you have already made up your mind on this - but I would start with the question of what your communications needs are? Are you traveling alone, or as part of a group? Edit - read your post more closely - you are traveling alone, so go with point A :ylsmoke:

A. If you are traveling in a single vehicle, I would ditch the radios all together and purchase an unlocked 'world phone' mobile phone and a sat phone. Surprisingly, I think you will find that the cell phone works in a lot of places and is by far the cheapest and most versatile option. In a lot of the developing world, wire line phones were skipped and the infrastructure went straight to cellular, so the coverage is often surprisingly good. The sat phone is for the places the cell phone doesn't work. I really can't see a situation where a radio would really be of much use.

B. If you are traveling as part of a group, then things become more complicated as you may want point-to-point communications, in which case a VHF radio may be of use, but may also get you in trouble and having to explain it at border crossings and the like. Text messages between sat phones are relatively inexpensive and could be a good option for point-to-point communications.

 

[ChadHahn]

When I was in Namibia a year ago, I was amused to see what I thought of a stereotypical scenes of Africa with a modern twist: women were walking down the road with loads on their heads and a cell phone to their ear. Even huts had a little solar panel built into the mud wall to supply power to phones. Rando is right that cell phone coverage is pretty good. Sim cards are cheap too. A sat phone and a cell phone would probably keep you in touch most places.

Chad

 

[texascrane]

A sat phone and a cell phone would probably keep you in touch most places.

A sat phone and a rock will keep you in touch most places

 

[Rando]

A sat phone and a rock will keep you in touch most places

True! But, given the choice, I would take a cellular phone connection over a sat phone any day of the week. There is a common misconception that sat phones just work - anywhere on the planet. This is not really the case. While Iridium does have global coverage, the link budget for sat phones is far more tenuous than for cellular phones and there are lots of situations where they really don't work well. This includes in deep valleys and canyons and under heavy tree cover where you don't have a good view of the majority of the sky. They also don't work reliably inside a vehicle or structure. In my experience, you can usually find a place where your sat phone will at least be able to get a text message out (with the exception of some canyons) but it might take some effort.

 

[Pilat]

Your cell phone works down canyons?

 

[ChadHahn]

Where are you going? Most countries have cell phone coverage maps. Looking at a map of Algeria, it looks like the north is covered but most of the south doesn't have cell phone coverage.


I was watching a Survivorman episode where he was on the top of a mountain in Romania. He had a sat phone and an Inreach and wasn't able to get a satellite with either of them. I'd rather have both a cell phone and a sat phone then just one or another. I would also be wary of having large antennas and fancy radios on my truck. I wouldn't want people to think I was a spy. In some countries, it's illegal to have a shortwave receiver.

Chad