The Idiot repurposed an old Army Radio

An ongoing experience merging old technology and newish technology.

Note: this is an ongoing project. It’s not quite complete, but I wanted to at least get a write up of my progress so far. This also assumes a bit of basic knowledge of installing an OS to an SD card for a Raspberry Pi.

Also Note: Please be careful with projects like this; you’re dealing with exposed electrical wiring that, if energized, can cause damage to the components and (more importantly) yourself.

So, back in the late summer of 2018, there was a flood that drove me away from my home for a few days. My Roommate and I decided to drive to the less affected Petersburg VA and turn it into a weekend of bar-hopping.

Somewhere between what I assume was Bar 3 and Bar 4, I stopped in a antique store and happened upon this Army Radio. So I sent myself a message on twitter:

So I picked up that radio (Model C-845/U) and it essentially was a paperweight for a few months. I wanted to do something with it, but I wasn’t quite sure what. I spent one weekend afternoon gutting the old internals (which I documented, but can’t seem to find the photos) and assessing what I could do with this radio chassis. Then an idea struck.

It had a working speaker, switches, dials. After gutting the internals it had plenty of room for all manner of components. So I bought a few things, mostly over time:

I opted for the Voice Hat because I essentially wanted to turn this into a new Google Assistant. However the code has been depreciated and no long works with the hot words “Hey Google” or “Okay Google”, so I’m still pondering around that that solution. However I can still use the Voice hat to push audio to the speaker for music.

To that end, the radio currently uses Tizonia to play music. Volume control is handled by a potentiometer that came with the radio.

I’ve wired the power to a toggle switch, which powers the “power” light, the USB wall charger and, by extension, the RPi. Yes, I know that this is not an optimal setup, especially since I cannot gracefully shutdown the RPi. I’ve been looking at an additional hat with capacitors large enough to properly shutdown the RPi on power loss. I’ve replaced the headset port with a HDMI+USB Extension, just in case I want to plug a monitor and keyboard into this.

I’m currently figuring out what to do with the DB gauge, the transmit light, or the “intercom” and “microphone level” dials on the case. The first idea is that the intercom dial changes the RPi’s mode (i.e. switch from music player to google assistant to whatever else I can think of.), but I don’t know how to pull that off from a technical standpoint. For the DB gauge, I may simply tie it to speaker output. However that seems uncreative.

A gutted chassis, with the RPi 3 (with voice hat) installed. As you can see, there’s tons of space here.
A birds eye view, showing the USB charger and the RPi3
The back of this radio offers a few options for providing power to misc components individually.

The more I play with this, the more I feel I could easily just make this a computer case with very few adjustments. I believe there’s enough space for a Mini-ATX setup as it stands. If I could get help properly stipping out all the old mounts and putting in a new bottom, I could definitely make a Mini-ATX setup work.

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