An F150 and Yaesu FT-857, ATAS-120 No-drill Install

I was a tad reluctant to drill holes through my new 2004 F150 truck's cab when first contemplating an amateur radio install for HF and VHF mobileering. I also wanted to aim for a few goals on the install:

1. Simplicity - few control lines and direct coax run; no passengers dodging 12V cables or coax

2. Ease of use - easy access to the transceiver and viewing of the rig's LCD

3. Simple install - no holes drilled (note that i ended up drilling two small holes anyway, but NOT for coax; four holes if you count the mic mount on the dash)

4. Done the "Right Way" - an install that lends itself to safety while driving and one that won't harm the vehicle

5. Some performance - the rig and antenna should work to some degree

6. Single antenna for VHF and HF communications - IOW, only one mount and coax

I found that I came up with a pretty good solution that's clean and works well. Here are the ingredients:

- Yaesu FT-857 DC-to-daylight transceiver
- Yaesu ATAS-120 mini-screwdriver
- Diamond K400C mount
- Comet CF-706A duplexer

Here's a pic of the antenna on the truck after the install. The antenna is mounted on a Diamond K400C mount, which uses four set screws to attach to the rear suicide door on the driver's side of the truck.

Here's a picture of the antenna mount, coax routing, and ground strap on the door. Note the broken screwhead in the door frame. This is what happens when you use too small a hole for a tap and cheap stainless screws. Ford is pretty good about strapping various parts of the truck for a common ground, as I found at least one good strap between the truck bed and cab. However, there wasn't enough contact between the door and cab frame (found after testing with my DVM), so I put a short strap on - much better! The ATAS-120 needs a good ground.

The K400C comes with six feet of thin coax. Before attaching the PL-259, the coax is conveniently slipped inside the rubber door gasket, then into the cab behind the seat, then underneath the middle of the rear seating area along the carpet. I bought a Comet coax extension to reach the rig, where the coax is attached to a Comet CF-706A duplexer (which has two 'stubby' coax connectors for attachment to the rig).

If you use the K400C, you'll have to re-tighten the set screws every 100 miles or so when first using the mount. Mobile ops are hard on equipment, especially antennas, so regular safety and maintenance checks are essential. That said, the mount has been steady and works great for me!

The hardest part of the install was finding out how to route the battery cables. A direct battery connection is mandatory unless you want to use a 100Ah deep cycle battery to run your rig. Here's a pic of the engine compartment, which shows the routing of the cable from the battery on the left, across the top of the compartment, then exiting through the firewall and the Ford's 2-inch rubber grommet conveniently engineered for running the cable.

The battery cable enters the cab through the firewall near the top of the brake pedal. The cable is run under the heating/AC vent then to the rig, which is in its mounting bracket. The bracket is clamped (using two 1.5-inch clamps) vertically to the middle seat of my F150's bench seat. Here's a shot of the rig and mic.

The rig is easy to see, the mic is easily retreived, and when I run mobile HF, all my fat fingers need to memorize are four buttons and knobs: the on/off button, the Tune button (button A when the 857's menu is set), the volume knob, and the select knob (i use 1kHz spacing). I use the large VFO knob once in a while.

All in all, this setup works fine for me! The ATAS-120 works by moving up and down according to 8 or 12 volts sent via the coax from the rig. This allows for a single cable run from the rig to the antenna! Tuning is fast due to the antenna's motor and small[ish] coil. An additional benefit is that the antenna works fine for 2M as well, giving me 2M through 40M mobile ops with one-touch tuning.

Happy mobiling!

bill, kg4zqz

last edited 04NOV04