We have been planning to install a mobile HF setup in one of our vehicles for some time now. Our car and truck currently have an Icom IC-2820h 2m/70cm DSTAR transceivers installed in them, providing access to our local repeaters. We also purchased a backup Icom IC-7000 Transceiver some time ago with the intention of installing it in one of our vehicles. Our planning for our Mobile HF setup involved talking to Ron Douglass at Scorpion Antennas and studying the excellent K0BG Mobile HF website. I’ve settled on the following components for our Mobile HF installation in our 2009 Ford F-150 truck:
- Icom IC-7000 HF Transceiver
- Scorpion SA-680 Screwdriver Antenna (80m – 10m)
- TuneMatic Automatic Screwdriver Antenna Controller
- Ameritron ALS-500M Mobile 500w Amplifier
This is quite a complex mobile installation – especially the amplifier plan. Given that I have limited experience with mobile HF, I am planning to complete the project in phases:
- Phase 1 – Install the Icom IC-7000 running barefoot with a simple MFJ HAMStick Antenna (to be replaced with the Scorpion Screwdriver Antenna in Phase 3)
- Phase 2 – Properly bond all elements of my truck and deal with any noise issues
- Phase 3 – Install the Scorpion Screwdriver Antenna and Controller
- Phase 4 – Install a 500w Amplifier, 160m capability, and operating accessories
This past weekend, we completed Phase 1 of the project – installing the IC-7000 Transceiver and a HAMStick Antenna in our F-150 Ford Truck.
The first step in the installation was to determine a good location for the IC-7000’s Control Head. It’s important to read the radio’s display and access its controls without taking one’s eye off the road. It’s also important to mount the unit so that it will not block the view of the road. After trying several locations while seated in the vehicle, I settled on a mounting location just below the top of the dash and just to the right of the steering wheel. This put the control head right in front of the driver in an easy-to-read and reach location.
I made a small bracket from some sheet aluminum which was attached to the underside of the dash pad with three screws. The bracket provides a secure mount for the Icom MB-105 Mobile Mounting Bracket for the IC-7000’s Control Head.
The next step was to mount the IC-7000 Main Unit. I mounted it on the right side of the front passenger area on the lower kick panel. I mounted the radio with the rear panel facing the passenger so that we could connect control and data cables to allow the passenger to operate using digital modes or connect a PC for automatic logging. This approach also makes working on the antenna, power, and other radio connections possible without removing the radio from its MB-62 Mounting Bracket. I removed the feet and handle on the radio, which allowed me to mount it closer to the kick panel, which helped keep the unit out of the passenger’s feet. At this point, I ran the radio’s power cable through a wire grommet in the firewall and connected the fused power leads directly to the battery. I also used Icom’s OPC-1443 Separation Cable to connect the radio to the control head mounted on the dash. The final part of mounting the radio was to run an audio cable from the radio to the auxiliary audio input on my truck’s sound system, allowing me to use the truck’s audio system and speakers to amplify to radio’s audio.
The final step of the installation was to install the MFJ HAMStick Antenna and mount. As you can see from the picture above, I choose to install the HAMStick on the roof of the truck. This approach works well because it allows the metal surface of the truck to act as the best possible ground plane for the mobile HF antenna.
I used an MFJ-336T Tri-magnet Base to mount the HAMStick. This base is solid and does not allow the antenna to move around on the vehicle. It was also a good choice as I plan to replace the HAMStick with the Scorpion Screwdriver Antenna later in the project. It was easy to route the antenna’s coax feedline through the corner of the door and then conceal it behind the trim panels in the interior of the truck as it was routed to the IC-7000’s base unit. The HAMStick antenna uses a spiral-loaded fiberglass section which includes a loading coil and a stainless steel whip on top.
The resonant frequency of a HAMStick is adjusted by changing the length of the stainless whip at the top of the antenna. As you can see from the picture above, I used our RigExpert AA-54 Antenna Analyzer to adjust our 20m HAMStick to favor the phone side of the 20m band. This tune-up will also allow operation in the 20m digital sub-band as well as in all but the very bottom of the 20m CW sub-band. We also purchased a 40m HAMStick. The bandwidth of the 40m HAMStick is limited due to its short length on 40m, so I tuned it to work best in the 40m DX window and the lower part of the US phone sub-band on 40m.
The last step in the installation was to secure a paper log and band plan to the truck’s center console using some large rubber bands. I use the paper log along with a small spiral-bound notepad to note information about my QSOs when operating mobile. The information on the notepad is transferred to the paper log when I am stationary.
With the installation complete and the 20m HAMStick installed, I made my first QSO with Ken (G0KEN) in the U.K.! The signal reports were 57 both ways, and we had a nice QSO on 20m. I do have some ignition noise when my truck is running, but the combination of the IC-7000’s excellent Noise Blanker and DSP Noise Reduction features reduced the noise level to S3 or less. I took my truck for a test drive with the new radio and worked a Special Event Station (OO7VA) in Belgium and several United States stations. All in all, our initial Mobile HF installation seems to be working quite well. The next step is to work on grounding the various parts of my truck and add some RF choking material to the power and other radio connections to try to lower the noise levels. This will be the topic of Part 2 of this series of posts.
– Fred (AB1OC)