Mobile HF Radio Install


Back in October 2022 I purchased a 2017 Ford F-150 and it has taken me until now (April 2024) to get my HF radio installed.  The final impetus was the upcoming Club mobile radio ‘show and tell’ event scheduled for Saturday 25th May.  Here’s a few words and photos to show how I chose to install the radio and antenna.

The first and for me the biggest dilemma is where and how to mount the antenna.  I already own a Yaesu FT-100D mobile radio and an ATAS 120A, which is a mobile antenna like a screwdriver antenna, that is designed to pair with Yaesu’s mobile radios (such as the FT-100D, FT-857, FT-891 and the FT-991A base station).  The antenna whip is driven up and down outside of a tuning coil by an electric motor to achieve resonance on all bands from 40 m up to 70 cm. 

There are many, many options for mounting the antenna.  Initially I though of using a stake pocket mount on the side of the bed at the back of the truck, but in my previous truck installation I found that with the antenna mounted in the back, it got in the way of loading the bed of the truck or putting a canoe on the roof, so I decided to put the antenna up front on the passenger side fender.  I already had the same mount for my VHF/UHF antenna on the driver’s side of the truck and have been very satisfied with that.  So, I duly purchased the mirror image Comet fender mounting bracket, $25 US from Ham Radio Outlet, to match the one on the other side of the truck.

The antenna mounting bracket uses an existing bolt under the truck hood and requires no drilling or adjustment.  The ¾ inch hole for the antenna is a bit large for the SO239 type attachment that the ATAS uses, but it works well enough.  I will monitor the ground connection as this is one area that I have found troublesome in the past with the ATAS antenna, which can stop tuning if the ground connection becomes poor.

Having made the difficult decision, I then opted to put the radio under the passenger side front seat, since I can run the power and coax cables down the firewall and under the vehicle to a handily placed drain point that has a rubber grommet in the passenger side footwell.  This means a fairly short power cable and coax run and there are easily removable panels along the door edge that allow me to hide the cables until they pop out at the side of the passenger seat.

For the radio, I chose to install my Yaesu FT-100D which is an all mode, all band 100W mobile radio with a removable control head that I have a mobile mounting bracket and separation kit for.  The FT-100D (long out of production) is similar in design and operation to the FT-857 (now out of production) and the current model the FT-891, and also similar to the QRP FT-817/818.  I chose to mount the radio control head on my existing Lido bracket mounted in the forward cup holder.  The only remaining task is to finalise a location and mount for the mic and to tidy the wiring between the control head and the radio body.

Photo 1 - Comet fender mount in place, showing how it follows the contour of the fender and uses the existing fender bolt to hold it in place.  The star washer on top of the antenna mounting bracket bolt improves the ground connection.  Also in the pic is the SO239 type right angle connector with the coax running back towards the firewall.
Photos 2 and 3 - The coax connection to the mount was sealed up with ‘Liquid Tape’.  Threaded washers were used top and bottom on the SO239 connector to provide a good interface to the mounting bracket.
Photos 4 and 5 - The power cable ends (fused on both the positive and negative wires) were connected directly to the positive and negative terminals of the battery and run to the fender.
Photos 4 and 5 - The power cable ends (fused on both the positive and negative wires) were connected directly to the positive and negative terminals of the battery and run to the fender.
Photo 6 - The power cable runs alongside the fender, joins the coax cable, then down the firewall and under the vehicle.
Photo 6 - The power cable runs alongside the fender, joins the coax cable, then down the firewall and under the vehicle.
Photos 8 and 9 - The power and coax cables drop out of the engine compartment and run alongside the chassis to reach the through hole grommet at the passenger footwell.
Photos 10 and 11 - The access point grommet was partly cut out to allow the cables to access the cab and then well sealed with Black Silicone sealant.
 
Photo 12 - With the cables hidden inside the door edging, they are kept tidy and free from damage.  From here they loop around the back of the passenger seat (under the floor mat) and up to the radio.
Photo 13 - The radio sits under the front of the passenger’s seat, again out of sight and protected from damage.  Control head and mic cables are temporarily routed up to the center console.
Photo 14 - The control head mounted on a Lido mount using the front cup holder.  My VHF/UHF HT with external speaker mic is below the control head.  Here both are within easy reach of the driver and cause the minimum distraction.

The whole install was completed in an afternoon and required only common tools except for the power pole crimp tool, since I chose to use Power Poles on the radio power cable.

I have tested the install by tuning the ATAS to the 40, 20, 17, 10 and 6 meter bands and making about 10 QSOs.  I also used it for a small number of my QSOs (and some attempted QSOs with Club members!) alongside a portable station while activating a POTA park and contesting in the Solar Eclipse QSO Party on Monday 9th April, so I’m happy to say the new mobile install works well.  Tuning across the band and using the control head switches is an easy reach from the driver’s seat, with the minimum of distraction.

Next steps.  Standby for an update on some minor repairs to the radio mic and for the install of my VHF/UHF mobile radio to replace the handheld that I have been using for the last year or so!  Let’s see if I can get that completed before the upcoming Club mobile radio show and tell.

Let’s see and hear about your mobile radio install.

Rob VE3RXH
Appears in: Rambler Vol.66 Issue 8