Electronics Overhaul!

I receive a lot of compliments regarding the level of detail and workmanship on my electronics panel. However, something interesting happens over the course of time as equipment is either added or changed, in this car as well as two previous cars: The addition of new power feeds, control cables, and coaxial feed lines often winds up detracting from my clean installation and can eventually contribute to a convoluted mess, especially in areas that are hidden from plain view. For example, the compartments under my rear seat delete have become catch-all spaces for leftover cable that I didn’t take the time to organize. Over time, that area has become a bit of a rat’s nest. It’s long past-due for an overhaul.

I found myself running out of space in my small car as I continued to expand my ham radio capabilities, especially now that I’m building a rover setup. Is it time for a larger vehicle? Not in today’s auto market! Instead, I decided to evaluate my needs to see if there was some shifting of priorities that I could make. Looking at the photo above, it’s easy to see that my subwoofer takes a lot of space under my trunk floor. Moving the subwoofer to the cabin would make a lot of new space in the trunk for my FT-857 and other new equipment. As I made my plan and inventoried my equipment, both present and incoming, I quickly broke my project into three phases.

PHASE 1 began with moving my 10-inch subwoofer. A realistic assessment of my listening habits led me to ask, “Do I really need this system today?” While I do enjoy the rumble of a good bass line from time to time, most of my listening these days is at lower volumes. For now, I decided to change my plan to favor returning the smaller Helix subwoofer to the car. Although the Helix setup is designed to replace the spare tire, this photo shows that it’s possible to mount the Helix sub AND retain the spare tire with the use of a longer spare tire retention “bolt,” VW P/N: 1T0-803-899-B. This option won’t work for me since I still need the space for my new electronics panel. I will use the longer “bolt” to secure my new panel, though.

“Hmmm, do I want a spare tire or good bass?” Well, I’ve never needed a spare tire since I carry a tire plugging kit. So, why not jinx myself by not carrying a spare tire? “Bass, it is!”  😉 If I’m honest, I do carry a spare tire if I’m traveling away from home. When driving locally, I’ll call a tow truck and get a lift to the nearest Discount Tire for warranty repair or tire replacement. I was pleasantly surprised by the sound of the Helix subwoofer. Sure, it’s no 500-watt setup, but it’s adequate for my usual needs. Plus, not having the extra gear frees space in my car for MORE communications equipment! 😀 I’ll share a new Helix review soon.

PHASE 2 included the removal of all electronics so that I could relocate it onto a new panel and rewire each component in an orderly sequence instead of a tangled mess. While the trunk was emptied, I took the time to replace my glitchy inductive trailer lighting controller and then added Noico sound-deadening matting to the floor and rear wall. My results were more subtle than dramatic. In this photo, all of the wiring was shoved under the rear seat delete so that I’d have a clear space when installing the Noico matting. I think most exhaust noise is coming through the hatch. So, I still need to deaden the hatch.

Untangling and then grouping the wires and cables into sections for each transceiver was a long and tedious process that took a few days! I also cut, crimped, and routed new DC wire pairs. I had lost a few wires in this mess and didn’t find them until I had sorted and neatly routed the wires where I could see everything. The coaxial feed lines for NINE antennas, with four more planned, were a separate challenge altogether! Sometimes, one must make a huge mess before things can get truly organized. I shot video sequences of the work, but it’s watchable only at 8000x speed. HAHA!

I alternated between working on the wiring in the trunk and working over the saw horses where I cut and mocked-up the new panel, shown here. You can see my three main transceivers, a voltage regulator, and a fuse block. The square holes are for coaxial feed line routing and are strategically placed over the channel that’s left between the Helix subwoofer (or spare tire) and the tub that holds them. There’s plenty of room for hiding coaxial feed lines, RF switches, and diplexers. Click the image to see a larger version where the line drawing is more visible. The round hole is for the extended spare tire retention bolt. Unlike my previous panel, this one will be held firmly to the car.

I am frequently asked to provide a template for the panel. Well, everyone already has one: The removable trunk floor that came with their car! I did a bit of extra trimming on mine because of how far I want it to open for servicing. You can also see the piano hinge and notching at the front since my panel extends farther forward than the factory floor. This photo also shows the spare tire retention nut, which I will find a creative way to hide. This panel presses the spare tire as the nut is cinched down. I added a thin layer of foam over top of the Helix subwoofer for additional support.

I was not pleased with the outcome of my carpeting attempt. I chose a thin carpet and didn’t get good application of the 3M Spray 90 glue. I ripped-up my carpet, sanded the panel, and then took it to the pros at Hampton Roads Customs. They did an excellent job; money well-spent for a panel that I hope to see last without the edges peeling for years to come. This photo shows the end state of Phase 2. Two of the four holes are cut to allow the passage of coaxial feed lines. The ground bar, timer, and the forward sides of each transmitter are hidden when the trunk floor is in place, even when lifted.

This photo shows the underside of the electronics panel. I will install longer cables between the transceivers and diplexers so that the diplexers can remain in the spare tire well when the panel is lifted. I’m not sure how tidy I can make this since there will eventually be A LOT going on in here with very limited space. I need to cut some channels in the underside of the panel so that feed lines and amplifier power lines are not pinched under the weight of the panel. I have not yet decided if I will ever paint the underside. That choice would be solely for aesthetics. Regardless, I will not add carpet. Doing so would cut into my already tight tolerances for equipment clearance above the panel.

My previous panel had a dedicated section for 12V distribution. I moved that to under the driver’s side storage compartment door. I mounted the WeBoost cellular signal amplifier there, too. The main 12V relay feeds my Victron Orion-Tr DC-DC charger, trailer lighting controller, an alternate path for powering my LiFePo4 battery‘s heater, and a backup charger connection for the LiFePo4 battery. Electrically speaking, there’s still room for growth, should I decide to add more circuits. Remember: this circuit is used only when the car is running. I don’t expect to add much more since the LiFePo4 battery carries most of my electronics load.

PHASE 3 will happen when I receive the amplifiers that have been on backorder since 2020. They’re expected in January 2023, but continually get pushed back. Adding the amplifiers will also bring a series of RF switches and diplexers so that I can choose which of my VHF/UHF radios I want to amplify and to what antenna I want to send the signals, all from the driver’s seat. The switches will add some insertion loss, but that’s an acceptable compromise for a setup that can be remotely operated without stopping to open any panels, especially if the trunk is loaded for travel.

I’ve shared more photos in the album below and will post a video soon.

Nutty, but CLEAN!


About Scott

I grew up near Houston, TX and served in the U. S. Coast Guard for over 30 years. I have an electronics background and continue to work in the electronics engineering field. I taught myself the basics about automotive systems as well as how to perform some of my own maintenance (cars and bicycles). I became involved with Amateur Radio and computers in 1995. The explosion of technology has made my job and several of my hobbies quite interesting. My hobbies include Volkswagens, bicycling, photography, electronics, amateur radio, web management, and reptiles. Visit my websites to learn more.
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