All Revved Up, No Place To Go

Today I got busy replacing my ignition switch and key cylinder. Because last month, I had set aside my lone RETROvan key for duplication and then promptly lost it.

I first ordered a replacement cylinder (only) but I couldn’t get the old one out of the switch because it was a slightly older design. Then I ordered a complete switch with a cylinder after finding the original Ford part for a 1961 P-400. But that one was completely different and didn’t fit the instrument panel. (I’m keeping it just in case.) So I finally figured out the rig didn’t have the original part, it had a universal Calterm part that may have been swapped in sometime later.So I ordered that since it looked the same. And you can see it comes with two matching keys.

Step One was to disconnect the starter battery. This involved simply lifting off my floor’s rubber puzzle tiles, removing my marine plywood hatch, then removing the steel diamond floor plate to access the battery shelf. Then I disconnected the Negative terminal.

Here’s the old ignition switch, which I removed from the instrument panel. Note that the instrument panel and all of its wiring hasn’t been restored yet. That’s an epic task for later this year, as part of Phase 3.

Taking careful note of the wiring on the old switch’s four terminal posts, I began transferring each group to the new switch.

And finally, I mounted the new switch into position through its hole. Then I noticed the nut you can see here is not the same as the original. It’s plastic—not metal, and it’s smaller. And worse, it doesn’t hold the switch as securely. So I’m not happy about that, considering that the photo on Amazon clearly showed a matching metal nut. But even my old nut doesn’t fit onto this switch’s threads. So, I’ll be following up with Amazon and Calterm to complain about false advertising.

But the good news for now is, the RETROvan started right up and the old Ford 3.6-liter 223-cubic inch inline six cylinder engine is now purring like a kitten on steroids.

Let There Be Music

Over the past two days I did the unthinkable. I tore open much of the driver side wall, top panels and berth base to run two new cables. One for left and right audio, and one for composite video. I plan to use the video cable later for my back-up camera, but I need the audio upgrade now.

This is the top corner panel behind the galley cabinet, which I had to disassemble. The dark gray cable up top is channeled through a pre-existing hole in the steel braces my Dad and I added. That way I avoided weakening those supports by drilling extra holes in or around them.

Here’s the audio cable, made by MediaBridge. This particular run is 25 feet long. I started by clipping off the 3.5mm Auxiliary jack and threaded that end of the cable from front to back through a total of four 3/8″ holes. I would later thread the separate (and thinner) video cable along the same route. This is all good because it keeps these signal-sensitive cables away from the noisier 120V and 12V power cables, while also protecting their insulated jackets from the heat of the aluminum roof.

Here’s the route they would eventually run, back to wall panel D6, just below RETROpod 3.

Here’s how they’ll terminate at the aft wall panel. This is a Leviton Decora QuickPort system, which I’ve used elsewhere in the RETROvan. The black versions have to be custom-ordered. The RCA jack modules snap into place after the wires are terminated into them. These jacks are not the simpler “pass-through” variety. That is, you can’t just plug an RCA cable into both sides of the jack. And that’s okay because an RCA jack is too big to snake through my routing holes.

The rear wires have to be crimped into the proper terminal slots, using the blue 110 Punch-Down tool you see on the right. That tool’s tip has a U-shaped “puncher” that pushes the wire into place. And then a small blade on one side of the tip trims the excess wire off. It took me a while to figure this out because I’ve never done this before and there are no instructions. You can find videos on YouTube but they tend to be geared for Cat5 (network) installations.

Here you can see the electrical box mounted through the wall panel and the 120V (with USB) outlet is wired up to the spare branch circuit I had the prescience to run months ago. The cables are stripped to reveal their inner conductors, which are still insulated at this point. In fact, the way the punch-down thing works, you don’t strip the wires yourself. You let the terminal blades slice through the insulation for you.

The thin black cable under my thumb is the video cable. It contains three wires: Yellow for video, Red for power, and Black for ground. Pretty straightforward.

The thicker dark gray cable is much trickier. As it turns out, the Red wire is the Right audio line. The Orange wire is the Left audio line—which should be White. And the frayed copper you see is the Ground. Apparently in this type of audio cable, the ground is common between both channels. And it is braided around the signal conductors to help shield them from outside RF interference.

The next challenge was to terminate the jacks and test them out. As you can see, this looks like a mess. I had to separate the ground wires and twist them into something resembling a single wire, one for each jack. There is potential here for a short or a loose wire. But at least the jacks would be easily accessible from the wall panel now. I just wish the ground had two separately insulated wires.

In this photo I’m holding the video cable up. That one was much easier to punch down into the Yellow jack, given that its Red power wire is unneeded for now.

And here it is all buttoned up. Works like a charm. And now, I can finally connect my iMac’s headphone jack to these wall jacks. And the sound comes out all four RETROpods in real time. No more Bluetooth lag. And that’s vital when working on music production with a MIDI keyboard.And as you may recall, I overcame the hideous Ground Loop Noise problem by using this gadget on my iMac’s headphone jack.

Ground Loop

I’ve been pulling my hair out, trying to piece together an even cleaner way to integrate various A/V components in the RETROvan.

My plan involves installing a second dual-gang outlet box on aft rear wall panel D6 using two USB-enabled 120V outlets and a pair of RCA audio jacks. This also involved carefully researching and purchasing three new cables and Leviton QuickPort modules. Those cables have to be the right lengths, they have to have the right connectors—and most importantly they have to be adequately shielded against RF interference.

The goal is to be able to connect my 5K iMac to the wall, and then to my AppRadio 4 receiver via the receiver’s AV input jacks, which are male RCA plugs. This direct connection would essentially eliminate any latency when playing music from my AKAI MIDI Controller keyboard, via Apple’s Logic Pro X DAW (Digital Audio Workstation). If connected merely by Bluetooth audio, you press a key and then hear the sound a half second later. And that’s not ideal. Normally this isn’t a problem because most of the time, you’re consuming A/V content not in realtime, but on a timeline that is kept in sync by your Mac and its operating system.

What I didn’t anticipate is something called “ground loop” interference. This manifests as a loud, low-pitched humming or buzzing noise playing through your speakers. This can happen when the components of your audio systems are connected to different power sources and/or at different voltages. There may be other causes, such as running an audio cable next to a power line, but that’s not a concern here.

In my case, my AppRadio is powered directly by a 12V circuit because it’s essentially a car radio. But my iMac is powered by a 120V wall outlet, fed from my ProMariner inverter. And apparently, the iMac’s headphone jack is not properly isolated or shielded. I know this because I can plug my new cable into the headphone jack of my TV or iPhone and the sound is crystal clear.

 

So next I tried a little gadget branded by Sabrent. It’s a USB Audio Adapter that plugs into your iMac and then you plug a 3.5mm headphone cable into the gadget. The assumption is that surely the iMac can produce digital audio that bypasses its own ground circuitry.

Same problem. Nothing but loud humming/buzzing noise. Apparently the iMac’s USB bus is still plagued by this design defect, and somehow that signal makes its way into any external analog jack no matter how far downstream it is. So next I tried isolating the problem with my favorite ThinkGeek external USB hub:

Same problem. I could try using a self-powered USB hub, but I’d still have to plug that into my 120V power so I don’t think it’s worth buying one.I eventually discovered this little device. It’s an inline Ground Loop Noise Isolator. I get it on Tuesday and can test things again then. My concern is that it’s basically a filter. So the question is, what other frequencies will it step on?