Long Distance Communications At 100 Legal Watts - From The Project Jeep To The Other Side Of The Planet
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HF (High Frequency) is the realm of Amateur Radio that allows you to communicate over really great distances. HF radio signals bounce off of the ionosphere and come back down to the earth. They can bounce back and forth many times, allowing for communications clear around the planet. It can be a lot of fun to speak to people in other countries. In a disaster, it can allow you to call in assistance when other means of communications are down, and you can relay traffic to locations well outside of the affected area. This can be traffic related to needed supplies and equipment for the disaster zone, or it can be passing messages from people in the affected area to family members in other places - letting them know how their loved ones are doing.
This happened a lot after Hurricane Katrina, and we were involved in passing some of that traffic.
From inside our Project Jeep, I have spoken with folks in Australia, Germany, Portugal, France, Canada, all over the USA, and many other nations. This was all done legally under the auspices of an FCC-issued Amateur Radio Operator License using a radio that has a maximum legal power output of 100-watts. No cell phone bill, no monthly fees, and no internet required. It's where a lot of the fun in Amateur Radio is. There are even contests to see who can contact the greatest number of people in the shortest possible time, or perform other tasks via radio. It can be a lot of fun.
The HF setup in our Jeep consists of an Icom IC-7000 radio, an Icom AH-4 Automatic Antenna Tuner, and an Icom AH-2b Antenna. If you want to consider some of the digital modes we have access to (RTTY, PACTOR, etc.), then the Toshiba Tecra A9-S9015X laptop and the Kantronics KAM-XL TNC are also part of our HF setup.
For those that are new to this, a TNC (Terminal Node Controller) is essentially a modem. Instead of connecting a computer to a landline phone line as a standard PC data modem does, a TNC connects a computer to a radio to send and receive data via radio waves. In our case, it connects the Toshiba laptop to the IC-7000 radio. It can even run TCP/IP. This opens up whole new worlds of communications.
Let's look at the individual parts of our HF radio setup.
We started with an Icom IC-706MKII-G. It is a great radio, and installed easily in our Tuffy Overhead Security Console. It provides full capabilities on all HF bands, plus 2m and 70cm to act as a secondary VHF/UHF radio. Here is shot of it installed in the Project Jeep. We figured it would be in there forever. The two grey cables coming out of the left side are used to connect to the KAM-XL radio modem. They are simply pushed back in when not needed.
We didn't figure that Icom would ever improve on the IC-706MKII-G. It really is one fantastic piece of radio gear.
We were wrong. They came out with a new radio called the IC-7000. It took things to a while new level.
We were able to test and review the IC-7000 and replaced the IC-706MKII-G with the IC-7000. It installed exactly the same way. Those details are in the Tuffy Overhead Security Console review and tutorial referenced at the end of this page.
The Icom IC-7000 is a fantastic little radio. It can run virtually all modes (SSB, AM, FM, CW, etc) on just about every legal Amateur Frequency from 1.7 MHz through 448MHz. It's compact and it includes literally every possible feature you could ever want. Suffice it to say that if you are looking to buy only one radio that will give you the maximum capabilities of whatever license you hold, the IC-7000 is your best choice at this time. If you have a Technican license, you can grow into it as you obtain your General and Extra licenses. Each license class offers more and more frequency permissions. This radio will allow them all.
The IC-7000 has a number of connectors on the back. The HF Antenna connection and a flat 4-pin connector are run through the back of the Tuffy Overhead Security Console, along the upper roll bar, down the drivers side, and to the back of the Jeep. This is where the Icom AH-4 Automatic Antenna Tuner resides.
The AH-4 is designed to tune single-wire antennas with a minimum length of 2.5m (about 98.5 inches) and an ideal length of just over 23'. It will tune from 3.5MHz to 54MHz (80m to 6m) with a 23' wire, and it is rated from 7MHz to 54MHz (40m to 6m) with the AH-2b. In reality, I have had it tune clear down to 80m with the AH-2b. It is an excellent tuner that exceeds the manufacturers specifications. It's also durably constructed and sealed, two features which are ideal for installation in a working Jeep.
Mounting the AH-4 tuner turned out to be relatively easy. It sits at the rear of the Jeep, held to the drivers-side rear roll bar via two long ZIP-ties. We did not use the included metal u-bolts due to the padding on the roll bar. The ZIP-ties worked better, hold it solidly in place, but can be quickly removed if necessary. We also used split tubing to further protect the antenna connecting wire.
The ground connection for the AH-4 is made to the bracket for the tailgate latching pin. This connection is vitally important, this must be a good electrical ground. We metered everything and this turned out to be an excellent ground point.
The included 4 conductor cable (which hooks to the flat 4-pin antenna tuner port on the radio) is connected to screw terminals inside of the AH-4, as is the PL-259 on the end of the included HF antenna cable. Everything you need (except for the long ZIP-ties we used) is in the package. It's a great deal for any Icom mobile HF radios.
The last main piece of the HF radio setup was an antenna. HF antennas are normally much longer than the VHF and UHF antennas we mounted on the front of the Jeep. This is dues to the relationship of wavelength and frequency.
Keeping in mind that this Jeep is performing the same functions that it's great grandfather did in WWII, we really wanted to find an old Jeep mounted antenna. That turned out not to be practical. We also toyed with the idea of using an antenna from a military hummer. They are avaialble in the surplus market, and are certainly beefy enough to take some punishment. Here is a photo of one installed on a military hummer.
As you can see, it is intended to mount to a surface with a 90-degree bend in it, and the antenna itself is VERY heavy duty. It is designed to last, but it would not work for our Project Jeep. The rear corners of our Project Jeep are rounded, and the stiffness of the antenna might present another issue. Fortunately, Icom also offers a solution, the AH-2b Antenna. It is designed to work with the AH-4 tuner, and includes hardware suitable for just about any mobile installation.
Here it is visible hanging over the top of the Jeep.
This was the most challenging piece to install. They have been around for a while, and are primarily intended to be installed on passenger vehicles that have a rear-mounted "tow hook". The instructions reference "tow hook", but this is different than the tow hook on a Jeep. They are referring to a round hole in a piece of steel hanging from the bottom rear of the frame of the vehicle under the rear bumper - the type found on many passenger cars to retrieve them if they run off of a road. Our Jeep did not have such (it has real recovery points), but Icom provides an option - a piece of sturdy aluminum designed to bolt onto a flat surface, and provides an appropriate metal loop for mounting the antenna itself.
We used that option and mounted our AH-2b as high as possible while making it a permanent part of the Jeep.
In the case of our Jeep, the previous owner had installed a TeraFlex CB radio antenna mount. We had re-located the CB antenna to the swing-out tire carrier on the Grant 4x4 rear bumper but did not remove this antenna mount. The TeraFlex CB Antenna Mount goes in behind the tail light, and it had a substantial hole drilled through it and into the body of the Jeep for a supporting bolt. A little enlargement of that existing hole allowed us to attach the L-angle bracket from the AH-2b kit, and the AH-2b is then bolted to that just like you would to a tow loop.
You need to make sure that bolt is tight or the AH-2b will tend to try to drop on that side. We made sure it was extra tight.
You will note that mounted in this position, the AH-2b does not interfere with the rear window or tailgate, even when folded down.
Once that is on, you are good to mount the AH-2b according to the directions. You will note that the directions make reference to using the AH-2b with the AH-2 and AH-3 antenna tuners. Rest assured that it does work just fine with the AH-4.
The AH-2b kit also includes an Antenna Element Catch. This is intended for mounting on a rain gutter or other point, and lets you flex the AH-2b over to clear low obstacles or tight trails. It worked fine on our hard top, and we even found that the side hole in the Carr Light Bar works too - but for a permanent solution (since it can pop out of that hole) we used a piece of wire to tie it down.
Once it is all installed and cabled, you are ready to run. Turn on the IC-7000 and tune to an appropriate HF frequency, then hit the TUNE button. You will hear a CW tone as the AH-4 is activated. It runs at only .3 Watts while tuning, so you minimize the risk of interference to other stations. Tuning takes a second or two. When complete, the tone stops and the TUNE light will be on solid.
After the tuning cycle is complete, you will note that you are hearing a lot more. You will also be able to transmit with maximum power if necessary. It's simple to use, and totally integrated.
In the event the antenna can't be tuned to the desired frequency, the tone will stop and the TUNE light will be blinking. This may happen if trying the AH-2b to something too low. One way to overcome that is to find a stationary location to operate from. Attach a length of wire to the tip of the AH-2b and run it into the air using a tree or other support structure (insulated, of course). Try to bring the overall length to just over 23', and you will have optimal results.
That covers the main pieces of our HF installation in our Project Jeep..
HF is where a lot of the fun is in Amateur Radio. Being able to run it from our Emergency Communications Jeep gives us more options. Being able to communicate in any mode on any legal frequency allows us to be flexible to act in whatever manner is best in the situation at the time. This setup really helps to accomplish this.
James Bell, Jr. - CommoJeep.com
Click Here To See How We Installed The IC-7000
Click here for the instructions for the AH-2b Antenna
Click here for the instructions for the AH-4 Tuner
Click here for the instructions for the IC-7000 Radio
Click here for a review of the Kantronics KAM-XL