Mobile HF Installation – Part 4/4 (500W Amplifier, 160M and Accesories)

Scorpion SA-680 Screwdriver Antenna

Scorpion SA-680 Screwdriver Antenna Setup for 80m – 15m

This article will cover the completion of our Mobile HF project. Our installation is fairly complex so we’ve broken the project into several phases:

The first step in this part of our project was to add upgrades to our Scorpion SA-680 Screwdriver Antenna to enable it to be used on 160m.

Screwdriver Antenna Configured For 160m

Screwdriver Antenna Configured For 160m

Ron at Scorpion Antennas makes an add-on coil unit to enable his 80m – 10m antennas to work on 160m. The picture above shows the add-on coil installed along with a 3 ft rod and Cap Hat. The coil adds additional base loading inductance to enable the antenna to work on 160m.

Antenna Base With Shunt Coil Switching Unit

Antenna Base With Shunt Coil Switching Unit

A different shunt coil is required to get the 160m configuration to tune up properly. Ron makes a very nice shunt coil switching unit (the grey box attached to the base of the antenna in the picture above) to allow multiple shunt coils to be used.

Antenna Shut Coil Switching Unit

Antenna Shut Coil Switching Unit

The unit contains two shunt coils (one for 160m and one for 80m/40m) and a 12V relay. The relay switches in the appropriate shunt coil under the control of a switch that I’ve added to our truck’s console. After properly adjusting both shunt coils, I was able to get a good match (SWR < 1.4:1) across the 160m, 80m and 40m bands.

The next step in this phase of our project was the installation of a mobile HF amplifier and some accessories to make the operation of our mobile HF station easier. As Alan Applegate (K0BG), author of the excellent K0BG.com website on mobile HF points out, installing an amplifier in a mobile application is not a trivial project. One must pay a great deal of attention to the following areas:

  • Beefing up the vehicle’s electrical system to be able to supply adequate 13.8V power (a 500W mobile amplifier will require 60A – 80A of sustained current when transmitting at full output and may draw close to 100A on peaks).
  • Proper physical mounting and adequate cooling to dissipate the heat generated (a 500W amplifier will generate approximately 500W of heat when operating at full output)
  • Proper choking of antenna control leads to ensure that conducted RF does not get into your vehicle or electronics (this areas was covered during the installation of our Screwdriver Antenna)
  • Drive/output power and SWR monitoring to ensure that the amplifier is not over driven and is working into a properly tuned and matched load

I am going to cover each of these points as they were handled in our installation.

Secondary Battery And Fuses

Secondary Battery And Fuses

It’s important that your vehicle’s alternator is capable of supplying enough current to operate the amplifier and the rest of your vehicle’s electrical system with overloading or major drops in voltage. We were fortunate that our F-150 Truck came with a 150A alternator from the factory. The next problem to solve is to provide 100A+ of peak current during transmit without excessive voltage drop (you want to have no more than 0.5V of drop between your primary battery and the power terminals of your amplifier). The easiest way to achieve this in our application was to install a secondary battery in the bed of our truck. We choose an Optima Red-Top series battery for both the secondary battery and as a replacement for our truck’s primary battery. The Red-Top series provides very high current for short periods of time (ex engine cranking). This profile is ideal of supplying a mobile amplifier. Both batteries are connected in parallel with custom-made 2 ga cables for both +13.8V and ground. The batteries must be identical when connected this way to ensure that differences in operating voltage do not result in uneven charging. It is also critically important for safety reasons to properly fuse the connections between the batteries at both ends and in both the +13.8V and ground leads! We used high current fuses (the insulated holders to the right of the battery in the picture above on both ends of the battery cabling. If either cable becomes shorted to the other or to ground, the fuses by the batteries will blow and prevent a fire. It’s also important to securely mount the batteries and the associated cabling and to properly protect the battery cables.  We used insulated cable clamps and convoluted tubing to accomplish this.

Ameritron ALS-500M Amplifier And Radio Interface

Ameritron ALS-500M Amplifier And Radio Interface

The next step was to select a location for the amplifier that enabled good air flow around the unit and to securely mount it to the floor of the truck. The spot that we choose was under the flip-up rear seat of our truck. The mounting location we used is at the corner of the seat which ensures good airflow around the unit. We also made an aluminum plate that sits between the amplifier and the carpet in the truck to ensure that cool air can circulate under the amplifier without being blocked by the carpet. The Ameritron ALS-500M Amplifier which we used comes with mounting brackets that allow it to be securely screwed to the floor of the truck so that it does not become a safety hazard during a quick stop, etc. We also installed an Ameritron ARI-500 Radio Interface Unit which provides automatic amplifier band switching and a keying interface for our Icom IC-7000 Transceiver.

Amplifer And Accessories Under Rear Seat

Amplifier And Accessories Under The Rear Seat

The picture above shows the location of the amplifier under the rear seat. Note the clear path that the vents in the case have to the air which circulates within the vehicle. There are air conditioner vents behind the front seats in the center console which can direct cool air on the amplifier during warm conditions.

Power Distribution, Antenna Controller And Wattmeter Sensors

Power Distribution, Antenna Controller And Wattmeter Sensors

The picture above shows the layout of all of the power and accessory electronics in our installation. Note the two high current fuses which protect the power connections between the amplifier and the secondary battery. We also installed a RIGRunner 4005 Power Distribution Block to supply 13.8V fused power to all of our accessories. We again used black convoluted tubing to protect all of the cabling and to dress up the installation.

Wattmeter Sensors And Screwdriver Antenna Controller

Wattmeter Sensors And Screwdriver Antenna Controller

The picture above shows the remote sensors (left) for the Elecraft W2 Wattmeter that we are using in our installation. A separate sensor is used on the input (200W range) and the output (2Kw range) side of the amplifier so that we can accurately set our drive power as well as monitor the amplifier’s output power and the SWR which is being presented by our antenna.

The TuneMatic unit is an Automatic Screwdriver Antenna Controller. This unit senses the frequency that our radio is operating on and automatically adjusts our screwdriver antenna to provide a good match. It also has auto-tune capabilities and includes an amplifier key line interrupter relay to ensure that we do not transmit high power into the antenna while it is being tuned.

Control Layout On F-150 Console

Control Layout On F-150 Console

All of the controls for the Amplifier, Screwdriver Antenna Controller and the Elecraft Wattmeter are mounted next to the driver on the F-150’s shifter console. We used heavy-duty Velcro strips to mount everything. The device in the right foreground is a Remote Control Unit for the Amplifier. The device in the left foreground is the control head for the TuneMatic Screwdriver Antenna Controller. Just behind the Screwdriver controller unit is a lighted 13.8V switch which we installed in the console to switch the shunt coil relay between the 160m and 80m/40m shunt coils. Finally, the unit in the background is the Elecraft W2 Wattmeter.

Antenna Controller, 160m Shunt Coil Switch, And Amplifier Remote Unit

Antenna Controller, 160m Shunt Coil Switch, And Amplifier Remote Unit

The TuneMatic Antenna Controller will automatically adjust our screwdriver antenna with a simple touch to the Tune (TU) button when the radio frequency is changed. This unit can also be used to manually move the antenna up or down to fine tune the match. There is also an auto-tune function which works well. An antenna controller such as the TuneMatic makes changing bands and frequencies much safer and easier to do and ensures that one keep their eyes on the road.

The Ameritron ALS-500RC unit provides a switch to enable or reset the amplifier if it should trip as well as a remote current meter which shows how much current the amplifier is drawing.

Elecraft W2 Wattmeter

Elecraft W2 Wattmeter

The Elecraft W2 Wattmeter worked out well in our mobile HF application. One can easily select the input or output sensors and its auto-ranging features provide accurate power and SWR readouts. It also has an LED brightness adjustment which is nice to have when operating at night.

Voltage Monitor

Voltage Monitor

It’s important to be able to monitor your vehicle’s voltage when using an amplifier. The heavy current demands of an amplifier at full power output can cause significant voltage drops, especially if the vehicle is idling and other power accessories like de-icers or seat heaters are in use. I found a simple and inexpensive solution for voltage monitoring – a unit which plugs into the cigarette lighter jack in the vehicle. The unit has an easy to ready display and it does not draw much current so it can be left plugged in when our truck is parked.

It took a little time to setup the TuneMatic Antenna Controller to quickly adjust the Scorpion Screwdriver antenna on all the bands from 160m – 10m. The instructions which come with the unit explain this process and it is not difficult to do. The TuneMatic must be configured to work with your particular screwdriver antenna when it is first installed. This involves setting some option switches and adjusting a pot inside the TuneMatic unit. Again, the instruction cover the setup steps well.

Icom HM-151 Microphone

Icom HM-151 Microphone

The Icom IC-7000 Transceiver is an excellent radio for mobile HF applications. Unfortunately, the quality of the transmit audio with the “stock” Icom HM-151 microphone which comes with the radio is less than ideal. To solve this problem, I sent my HM-151 microphone to Bob Nagy (AB5N) for some upgrades. Bob performed a number of upgrades which included replacing the element with a higher quality unit, installing a heavy-duty PTT switch, weighting and vibration deadening the housing and other mods. After adjusting the equalization in the IC-7000 to match the new element, we are getting some very nice reports on our audio quality from the stations that we are working while mobile.

You can click on the above video to hear what our mobile HF station sounded like in Europe during some initial testing with the new amplifier and upgraded microphone. We were still adjusting the audio settings when the recording was made but it will give you an idea what the setup sounds like on the air.

There was quite a bit of integration and working with the folks at all of the companies who supplied the components for our mobile HF project. Ron Douglas at Scorpion Antennas, Mike at Ameritron, Jim at TuneMatic, Bob Nagy (AB5N Microphone Upgrades) and the folks at DX Engineering were all very helpful in answering our questions and getting everything to work together.

Scorpion Whip Quick Disconnect

Scorpion Whip Quick Disconnect

We are operating across a very wide range of bands (160m – 10m) and I’ve found that it best to use a range of “whips” on our screwdriver antenna to cover all the bands. The Scorpion Quick Disconnects make changing “whips” a snap. Our “go to” configurations are as follows:

  • 160m – We use the add-on 160m coil plus a 3 ft rod with a Cap Hat. The Cap Hat makes the rod appear electrically longer and this improves overall efficiency on the Top Band. This combination allows the antenna to be tuned for all but the top 50 kHz (above 1.950 MHz) of the 160m band.
  • 80m – 15m including 30m and 17m – We use a 4 ft rod with a Cap Hat. This combination is very efficient and our results on 80m have been particularly good. I am able to work DX from New England, USA into Europe on 80m with 100W (amplifier off) using this combination. The 4 ft rod/Cap Hat combo is electrically too long to tune above the 15m band. The 3 ft rod/Cap Hat will tune up on the 12m band but not on 10m.
  • 12m and 10m – We use a 6 ft whip for these bands.

We really like the combinations which utilize a Cap Hat. These setups are definitely more efficient than the 6 ft whip and the overall height of the combination is low enough to stay out of the low tree branches here in New England, USA. The Cap Hat combinations allow less of the screwdriver antenna’s coil to be used. The coil is one of the largest sources of loss in a well installed screwdriver antenna setup and this is why the Cap Hat/short rod combinations work so well.

It’s nice to have the extra power when operating from our truck and I find that I can call CQ and sometimes generate a pileup while operating mobile! I’ve also been working quite a bit of DX from our mobile HF station (95 DXCCs worked so far) and the improved antenna and the added power has certainly helped in this area as well.

We hope that you have enjoyed our series of articles on our Mobile HF project. We have learned a great deal doing the project and we’ve made over 600 contacts from our truck along the way with many more to come.

– Fred (AB1OC)

Mobile HF Installation – Part 3/4 (Screwdriver Antenna Installation)

Icom IC-7000 Mobile HF Radio

Icom IC-7000 Mobile HF Radio

We have made some 250+ contacts using the Mobile HF setup in our Ford F-150 Truck. Our initial setup used an Icom IC-7000 Transceiver and HAM Stick Antennas. This combination enabled us to work quite a bit of DX from our truck (56 DXCC’s worked mobile HF to date). It is surprising how well a properly installed Mobile HF setup works. For more information on our Mobile HF installation project, see our other articles here –

It has been part of our plan to enhance our Mobile HF installation to include a Screwdriver Antenna and a Mobile Amplifier. This article cover the first of these upgrades.

Scorpion SA-680 Screwdriver Antenna

Scorpion SA-680 Screwdriver Antenna

We chose a Scorpion SA-680 Screwdriver Antenna for our project. Scorpion mobile HF antennas are among the best on the market in terms of quality and efficiency. The SA-680 covers all HAM bands from 80m – 10m (160m operation will also be added to this antenna – more on this in a later post). The SA-680 is also a good choice given our plans to add a mobile HF amplifier to our truck (the SA-680 is rated for 1500 Watts SSB PEP). We ordered our antenna with a flat black powder coated finish to match the color scheme on our truck. Scorpion antennas can accommodate a variety of whips and we have both 6 foot (supplied with the antenna) and 8.5 foot whips available. We also ordered a 3 foot long rod with a Cap Hat and this is the combination that we are currently using. This arrangement features improved efficiency due to the top loading of the antenna provided by the Cap Hat and a reduced height profile which is perfect for avoiding the low tree branches here in New England, USA. Ron Douglas, NI7J owner of Scorpion Antennas has been a great help providing lots of good advice to help us to install his SA-680 antenna properly.

BreedLove Folder-Over Antenna Mount

BreedLove Folder-Over Antenna Mount

The Scorpion SA-680 Antenna is a beefy unit and weights about 18 pounds. This antenna requires a strong mounting system for safety and reliable operation. We chose to mount our antenna in the bed of our F-150 Truck using a fold-over mount from Breedlove Antenna Mounts. This mount is made specifically for the Scorpion Antenna and uses 1/2″ thick aluminum plate with reinforcing bars that mount under the truck bed to ensure that the mount is rigid and does not crack the truck bed due to the load of the antenna. As you can see from the picture above, we cut the plastic bed liner which protects our truck’s body to allow the base of the antenna to sit on the truck body’s sheet metal. We used star washers between the mount and the bed to ensure that the mount made a good RF connection with the bed of the truck.

Antenna In Folder Down Position

Antenna In Folder Down Position

One of the nice features of this mount is its ability to be folded over to 90 or 45 degrees. This is done by loosening two large allen screws on the mount. The picture above shows the antenna folded over with the Cap Hat/Rod removed. In this position, we can close the roll cover on our truck’s bed to completely cover the antenna. This is great for taking the truck through the car wash or when we want to protect the antenna from the winter weather here in New England.

Scorpion Whip Quick Disconnect

Scorpion Whip Quick Disconnect

Removal of the Cap Hat/Rod or an attached whip is made easy by Scorpion’s Quick Disconnect. The ones on our antenna are made from stainless steel and allow easy removal of the Cap Hat Rod or a whip.

Control And Feedline Choking

Control And Feedline Choking

All Screwdriver antennas require control cables to operate a motor which raises and lowers the antenna to change the length of a base loading coil. This is how the antenna is tuned to operate on different bands and frequencies. The motor and associated control leads operate at a high RF potential relative to the vehicle’s ground. This is also a problem for the outside shield on the coax cable feeding the antenna. The RF potential on the control cables and feedlines must be choked or it will enter the vehicle and cause all manner of RFI problems. Proper RF choking is especially important in our installation as we plan on running high power via an amplifier. To ensure proper choking, we built a series of RF chokes for the six control lines from the antenna – one pair for the 2 motor leads, one pair for the 2 pulse count leads that are used to sense the position of the antenna, and one pair for a future shunt coil relay to enable 160m operation. These chokes were built according to the information on K0BG’s excellent Mobile HF website. Each pair of control leads were run through two separate chokes at the base of the antenna (two chokes were used to due to the planned high-power operation with an amplifier). Two chokes were also used on the RG-8X feedline. For the initial installation, the supplied shunt coil (copper coil on the left side of the antenna base) was used to match the antenna on 80m and 40m. The coil was adjusted using the procedure on K0BG’s website to achieve a good match on these bands. Also note the ground strap (visible to the left of the fold-over base). This connects to one of the button head screws at the base of the antenna and to the ground point on the antenna mount to ensure a good ground between the antenna and the truck.

Chokes Inside The F-150

Chokes Inside The F-150

Another set of control cable and feedline chokes were made and installed at the point where the antenna cables and feedline enters the vehicle. The picture above shows some additional detail on how the chokes are made. It is important that the chokes be at the same point on each of the control cables and coax feedline so that any RF induced on the cables does not couple from one cable to another and bypass the chokes.

Additional Bonding and Cables Mounting

Additional Bonding And Antenna Mount Grounding

I decided to do some additional work on the bonding of the bed of our truck to the rest of the F-150. This involved installing 4 bonding straps between each corner of the F-150’s bed and the frame. I used the excellent strapping material from Electric Motion for this purpose. This strapping features eyelets which are installed every 3 inches along the strapping material. This made attachment of the strapping to the F-150’s bed and frame easy to do via self-taping stainless steel screws and star washers. A liberal coating of Ideal NOALOX was used on each of the screws and washers to protect against corrosion. Also note the convoluted tubing which houses the antenna control leads and feedline running along the frame. The tubing protects the antenna’s cabling and feedline from the weather and enables secure mounting to the vehicle’s frame.

Screwdriver Antenna Manual Controller

Screwdriver Antenna Manual Controller

The final step in the installation was to connect the antenna control cables to Scorpion’s antenna control switch and mount the switch on the console with velcro strips. This switch is used to raise or lower the antenna, changing the length of the loading coil to tune the antenna for different bands and frequencies. I also installed crimp-on connectors on the RG-8X feedline and connected it to the radio and to the antenna. A quick check of the antenna’s SWR on 20m confirmed that the antenna and feedline were working correctly.

I was able to make contacts on the 17m, 20m, 40m and 80m bands with the new antenna last evening and it works great. I am particularly pleased with the antenna’s performance on 80m. I made several contacts on this band out to about 2,000 mi and was receiving signal reports ranging from 58 to 59+20dB. These results are very good considering the short length of the antenna’s Cap Hat/Rod (only 3 feet) and that I was using only 100W.

*** Safe operation of your vehicle requires your full attention on the road. You SHOULD NOT try to tune your antennas or your radio while your vehicle is in motion. Safety requires that you perform these actions only when your vehicle is stopped and parked safely. ***

The antenna is easy to tune manually. One simply sets the radio to the desired band/frequency and then adjusts the antenna up/down until the maximum reading on the radio’s S-meter is obtained. This usually gets you to within a “coil turn” of the optimal tune-up. I then key the radio up and adjust the antenna up or down a bit to optimize the tune to the lowest SWR as indicated on the radio. The antenna’s tuning is not critical on 20m and higher bands. It is fairly sharp (due to the short length) on 40m and 80m so final adjustment to minimize the SWR is important on these bands.

It’s great to have the full set of Amateur HF bands available in the truck with the new antenna. Performance seems comparable to the Ham stick antennas I was using previously on the 20m and higher bands. I would say that this indicates that the efficiency of the Scorpion SA-680 is significantly higher than the Ham stick antennas because the Ham sticks where mounted dead center on the roof of my truck and about 3-4 ft higher than the Scorpion. While this location performed reasonable well on 20m and higher bands, it was not a very practical mounting location due to height problems and the difficulty in getting at the base on the antenna to change or remove the Ham sticks. Performance is also much better on the 40m and 80m bands with the new antenna. I would say that the new antenna is also somewhat quieter than the Ham sticks were. This is probably due to a combination of being further away from the engine and cab noise sources plus benefits due to the additional bonding work.

The next stage of our Mobile HF project will be the installation of a mobile amplifier, automatic antenna controller and 160m band add ons to the Scorpion antenna. I hope to work some of our readers on the HF bands from our truck soon!

– Fred (AB1OC)

Mobile HF Installation – Part 2/4 (Bonding and Choking)

Transceiver Ground

Transceiver Ground

This article will cover the second phase of our Mobile HF project – bonding and grounding.The following is a summary of the phases of the project:

We have been having fun with our new Mobile HF installation in our 2009 Ford F-150 Pickup Truck. We are currently using a simple HAMStick antennas to operate on the 20m and 40m bands. The initial installation focused on getting the radio installed in the truck and working and while this was successful, we have had to work around quite a bit of electrical noise when the vehicle is running. The noise was S9 without the Icom IC-7000 Transceiver’s Noise Blanker turned on and about S3-S4 with the Noise Blanker on. Most of the noise sounded like ignition or fuel injector spikes (it was engine speed dependent) and I understand that this is quite common with the Ford F-150 Truck. This past weekend, I set about solving the noise problems via a combination of Bonding and Choking techniques. An excellent source on how to approach this can be found on the K0BG Mobile HF website.

The first step in the process was to ground my radio to a solid point on the truck’s body. I used 3/4″ wide ground braid from DX Engineering (picture above) for this purpose. I was fortunate that my F-150 had Truck had good ground straps installed between the body and the frame at the factory (although I do plan to supplement these with heavier straps in the future).

Power Connection Choke

Power Connection Choke

Next, I added Type 31 choking material to the transceiver’s power and antenna leads. I added a total of three beads on the power leads (one in the engine bay close to the firewall and two on the interior side of the firewall). I also installed choking material on the antenna coax near the radio. The correct way to install these beads is to coil the cables through them as many times as possible to form an effective RF choke. With these initial steps, my noise fell from S9 to about S6-S7 without the Noise Blanker.

Hood Bonding

Hood Bonding

The next step was to bond the hood of the vehicle to the rest of the body via 1″ wide ground braid. These were made from material that I purchased from DX Engineering and they were installed on both hood hinges.

Body Bonding

Body Bonding

I also installed two bonding straps between the cab and the bed of the truck (one on each side).

Exhaust Bonding

Exhaust Bonding

Finally, I used kits from DX Engineering to bond my exhaust system to the frame of the truck. This needs to be done in three places – at the exhaust pipe section which is connected to the engine, on the mid-pipe which leads to the front of the muffler (shown above) and at the tail-pipe which leads from the read of the muffler to the rear of the truck. Exhaust system bonding is probably the most effective technique for reducing electrical noise in most installation and mine was no exception.

With these additional steps, I my noise level was reduced to S0! While I still have a faint amount of engine electrical noise, I can operate without the Noise Blanker on and with a lower level of Noise Reduction than before the steps outlined here. My installation is much quieter overall and I find that I am hearing many more stations than I did before. There is still more work that I plan to do in the future including bonding the truck’s bed to the frame at all four corners, improving the existing factory grounding between the body and the truck’s frame, and bonding the four doors to the body. For now, my Mobile HF operating experience has been improved considerably.

The next stage of our Mobile HF project will be the installation of a Screwdriver Antenna. We also plan to install a mobile HF amplifier for high-power operation as well as other upgrades.

– Fred (AB1OC)

Mobile HF Installation – Part 1/4 (Initial Installation)

Mobile Installation In Ford F-150

Mobile Installation In Ford F-150

We have been planning to install a mobile HF setup in one of our vehicles for some time now. Both our car and our truck currently have Icom IC-2820h 2m/70cm DSTAR transceivers installed in them which provide access to our local repeaters. We also had 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 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:

This is quite a complex mobile installation – especially the plan to use an amplifier. Given that I have limited experience with mobile HF, I am planning to complete the project in phases:

We completed Phase 1 of the project this past weekend – installing the IC-7000 Transceiver and a HAMStick Antenna in our F-150 Ford Truck.

Icom IC-7000 Control Head

Icom IC-7000 Control Head

The first step in the installation was to determine a good location for the IC-7000’s Control Head. It’s important to be able to read the radio’s display and access its controls without taking one’s eye’s off the road. It’s also import to mount the unit where 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.

Icom IC-7000 Head Unit Mounting Bracket

Icom IC-7000 Control Head Mounting Bracket

I made a small bracket from some sheet aluminum which 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.

Icom IC-7000 Radio Mounting

Icom IC-7000 Main Unit Mounting

The next step was to mount the IC-7000 Main Unit. I choose to mount 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 easily 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 it possible to work on the antenna, power, and other radio connections 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 helps to keep the unit out-of-the-way 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.

Mobile Antenna Farm

Mobile Antenna Farm (HAMStick Is Center Antenna)

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.

HAMStick Magnetic Mount

HAMStick Magnetic Mount

I used an MFJ-336T Tri-magnet Base to mount the HAMStick. This base is very 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 in a later phase of 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.

20m HAMStick SWR

20m HAMStick SWR

The resonant frequency of a HAMStick is adjusted by changing 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.

Mobile HF Log

Mobile HF Log

The last step in the installation was to secure a paper log and band plan to the center console of the truck using some large rubber bands. I use the paper log in conjunction with a small spiral bound notepad to note information about my QSOs when operating mobile. The information one the note pad 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 as well as several stations located in the United States. All in all, our initial Mobile HF installation seems to be working quite well. The next step is to work on the grounding of 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)