Schlatter Family Site

My Mobile Radio Installation
Page Two

General background

The following describes how I installed a Yaesu FT-857D and two antennas on my 1997 Mazda B4000 truck.  I will describe the way I mounted the radio front panel so it's accessible by the driver; how and where I mounted the antennas; and, how I routed the wiring and cable.

Power wiring

You will hear different opinions about where to get power from your radio -- but everyone who offers advice will agree on one thing: DO NOT take power from the cigarette lighter, from the accessory 12-volt power plug, or from the fuse panel.  The best place to get the power for you radio is DIRECTLY FROM THE BATTERY.  Run two big wires -- #6 stranded or larger  -- from the battery positive and negative leads directly to the radio.  Put fuses in both the positive and negative leads right where the leads connect to the battery.  There are a lot of reasons for this but, trust me -- take power straight from the battery and fuse the leads at the battery.  Your rig -- if you buy it new -- probably will come with a two-wire power lead with fuses installed, ready to be installed in the vehicle.

Here is a picture of my connection to the vehicle battery.

I crimped ring connectors to the bare ends of the red and black wires that make up the power lead supplied with the FT-857.  I then loosened the bolts that clamp the battery connector to the battery posts and put the ring connectors under the heads of those bolts and tightened the bolts.  Note the two fuses -- these are 25-amp automotive blade fuses in holders; they are part of the Yaesu power cable.  If your power cable does not have these fuses, go to a local auto parts store and look in their electrical section -- you will find in-line fuse holders with 3-4 inches of wire coming out of each end -- get two of these and put them in your power leads at the battery, as shown here.

At my local Home Depot store, in the electrical department, I found a 10-foot length of cable covering.  It's hard plastic, ribbed, slit down its length.  It's intended to have wires stuffed inside it and is protects the wires.  Look at this photo, just above the fuses, and you will see the red power lead going into this ribbed, plastic cable conduit.

From here, the power lead runs down underneath the cab of the truck.  I found, in the floor directly below the seatbelt retractor, an oval-shaped hole that was closed with a rubber plug -- this is probably an access hole for removing/installing the seatbelt retractor.  I removed the rubber plug and cut a small hole in it, just big enough to pass the power lead and that's how the power lead goes into the cab.  Use nylon cable ties along the length of the power lead to tie it to tie points along its route --

• Power lead should be secured tightly at several points along its length with nylon ties.
• Do not let the power leads rub against sheet metal -- the sheet metal will cut the leads.

The antenna mounts

I mounted my antennas in the stake holes on the bed of the truck.  Here is a photo of the finished antenna installation followed by an explanation of the installation.

Here are the two antennas installed in the rear stake holes -- ASAT-120 for HF and 6 meters on the left, dual VHF/UHF antenna on the right.  Read on for the details.

The best place to mount a mobile antenna is in the center of the roof of the vehicle -- so the antenna has a good ground counterpoise from the vehicle roof.  However, to do this you must:  drill a hole in the roof, being careful not to drill through the headliner inside the cab; fish the coaxial cable through the hole, under or through the headliner and roof insulation down to the rig; and mount some kind of antenna connector.  If you ever remove the rig, you are left with a hole in the roof.

I found these stake hole mounts manufactured by GeoTool -- here is a link to their website:
http://www.geotool.com/antmount.htm

The GeoTool website is excellent -- the site contains photos of the mounts, installation instructions, photos of finished installations, and ordering instructions complete with instructions as to how to measure your stake holes to ensure you get the right mounts.  And -- when you submit your order, Rick will check your order and contact you if he spots anything amiss -- I made a mistake in measuring my stake hole, Rick questioned my measurements; he sent me an e-mail suggesting that I double-check my measurements -- he was right.  I received the mounts from Rick four days after ordering them.

And, while I am on the topic -- Rick's installation instructions for the GeoTool stake hole mount are excellent.  I built a lot of old Heathkits way back when Heath was still in business and the Heathkit assembly instructions are generally recognized as the best ever -- clear, well-illustrated, step-by-step, you can't go wrong.  Rick supplies installation instructions with his mount that are every bit as good as the old Heathkit instructions -- you cannot go wrong with his instructions.

Go to Rick's website and read everything there for the details.  Here is my installation.

The following photo shows my stake hole mounts.  The mounts come with your choice of antenna connectors -- I ordered one VHF for the PL-259 end of the ATAS-120 and one NMO for the VHF/UHF antenna.  The mounts DO NOT COME WITH COAX.  You will need to get some coax and PL-259 connectors for the coax -- the GeoTool mounts come drilled to accept RG-8X -- I used RG-8X with double-shield from Radio Works.

This slightly out-of-focus photo shows one stake hole mount with the NMO base connector installed.  Look at the bottom of the mount where you see a threaded hole.  In the plastic bag is a bolt with a hole drilled down the center, several flat washers, and a toothed lock washer.  Note also that the coax is routed through grooves cut into the mount.  In some cases you may need to feed the coax through the hole drilled in the center web of the mount and down through the hole in the mounting bolt.  In most cases, though, you can run your coax just like this.  Soldering the coax to the connector requires attention to detail -- you are working with tiny contacts in a tight space -- read Rick's instructions, look at it, and plan what you are doing before you start.  If you screw it up, unsolder it, trim the coax, and start over.

The photo below shows a GeoTool mount with a Type M VHF connector installed -- this one fits the end of the ATAS-120 antenna.

This mount comes with a cap to protect the threads on the connector -- the cap is in place in this photo.  This one is a little tricky to solder -- look where the coax goes into the connector and you will see a big, Allen-head setscrew.  You must remove this setscrew, strip the insulation off the tip of the coax center conductor, tin the center conductor, then -- insert the coax through the bottom of the connector and stick your soldering iron through the hole where the setscrew was in order to solder the center conductor onto the coax connector.   You will need a small, pencil-tipped soldering iron.  It's not difficult -- I did it the first time -- look at it carefully before you start work and follow Rick's excellent instructions.  On this mount, I ran the coax through the hole in the mount -- this photo also shows the mounting bolt in place on the bottom of the mount.

The next page has photos of these two mounts being installed and the coax being routed into the cab of the truck.