Welcome back to my Go Box (GB) series. I’m not sure if you can really call two a series, but since this will likely go to three, I think we’re good, so here we go. In part one, we looked at what you might call a more traditional GB, similar to the majority of examples I saw online when I was doing my research to build my own. Now I don’t mean traditional in a negative sense. These rigs are functional, pretty sturdy, and can take a lot of abuse during transport and storage. I really like mine and it works extremely well for its intended purpose. However, I wanted to build one that was a little different and I took my inspiration from a REDDIT forum on cyberdecks that you can check out here. Also, in order to differentiate between the two go boxes I will continue the naming convention from Part 1 and refer to them as GB1 for the one we covered in the first part, and GB2 for the one we will be discussing here.
What is a CDK? It seems they originated in the online gaming world and essentially are custom, portable computing devices built to meet the needs of their users. Be that hacking, non-sanctioned access, etc. Not that I advocate any of those or related activities. Okay, so what does that have to do with ham radio? Well, as I was going down this rabbit hole of exploration, I got to thinking about my first go box build with the integration of a raspberry pi as a sort of system controller. Additionally, the usefulness of being able to have a lot of information at my fingertips in the form of manuals and radio support data has proven beneficial to support a prolonged deployment or extended time away from the benefit of the internet.
In fact that idea led me to several builds that were focused on what is nominally called a “Crash Recovery Device” or CRD (you can see an example here). This is a specific type of CDK that combines extreme nerdism, with an apocalyptic bent, to build a device that can contain a significant amount of data and human knowledge in case the world comes to an end and we have to try and survive from scratch. Should we really end up in a SHTF situation, the internet and all of our normal information sources may go the way of the dodo, or at least be unavailable for a long period of time. Okay not exactly an uplifting topic, but the geeky side really appeals to the DIY Ham! (Did you know that you can fit the totality of the English version of Wikipedia, including pictures, in less than 100Gb? That is absolutely cool!)
So I got to thinking, what if I built a CDK/CRD, that also had ham radio communications capability, and that fit in a single, self-contained, sealed case? After a lot of drawings, figuring, and much head scratching, GB2 was born. My initial goals for this were:
- HF through UHF capability
- Voice and Digital modes, to include packet, simultaneously
- Raspberry Pi 4 or better
- 100G+ storage to store Wikipedia and anything else I might want when everything goes South
- Built in screen, keyboard, and mouse/trackpad
- Weather tight (this one had a few compromises due to the need for heat dissipation)
- Self-powered (this one didn’t pan out either due to weight vs operating longevity and required a rebuild into the version 2 shown in this article)
- Carry in one hand, since as a rack, GB1 really needs two hands to move around
With these goals in mind I set out to assemble the necessary gear on a limited budget.
I was never going to be able to justify buying new radios for this box so I waited until I could go to my next hamfest to see what deals I could swing. Well, as it so happened, our local hamfest organization finally was able to put on a limited event in the fall of 2021 (thank you COVID) and though it was a small event, I thought it was a great success. Of course I came away with a very high opinion because I scored two significant deals on the two used radios I eventually would put into GB2:
- Yaesu FT-857D
- Yaesu FTM-350
Even though I did have to replace the display in the 857, due to the dreaded zebra stripe syndrome, the overall cost was still significantly below what I would have had to pay on Ebay (if I could even find one there).
The next task was to locate a screen. As you saw in the first installment, I salvaged a screen from a dead laptop. If you followed the link to DIY Perks, you also learned that I would need to buy an interface card based on the model of the screen. In GB1, the screen is mounted inside the front cover along with the interface card and the control board. So for GB2, I decided to do something similar and happened to have another laptop that had given up the ghost, but had a good screen. So for GB2 the screen was mounted on the front plate and the interface card attached to the back side. With the screen element solved, I turned my attention to how I was going to mount it.
You see at about this time I was also looking for the case to house this build and had finally decided on a “Pelican Like” knock off case from Harbor Freight. If you’ve taken the time to follow the links above to any of the Youtube videos on CDKs/CRDs you likely noticed this type of case being used in their builds. However, since I was incorporating a laptop screen, which is bigger than the 7” pi screens most of them use, and I was installing mobile ham radios in the case, I needed something just a little bit bigger and settled on the Apache 4800 case.
After doing some modeling in Sketch-up I figured out that I could get all of this gear into the volume of the case, I just had to be creative about it. As shown in the CRD video, the bulk of the equipment is housed in the larger portion of the case, what would normally be the part facing up when open. That also means the “lid” is where the keyboard rests. This arrangement allows for a more comfortable operating position. This is how I chose to build mine as well.
Since I had great success using a Raspberry Pi 4 (RPi4) in GB1, I wanted to do the same in GB2. In version one of GB2 I stole the RPi4 from GB1 initially to evaluate mounting, case, etc. to determine what I would get as a final version for GB2. Well, things worked well and I was able to find a keyboard that fit the lid and also have a place to store the mouse and a few other items (like mics for the radios), but the RPi4 itself was buried inside the upper case and not really accessible for any type of maintenance or changes. Also the lid arrangement just seemed clunky and using the mouse was a headache because it had to be on its own pad outside the lid. Not to mention, the price of RPi4’s was steadily climbing. Enter the RPi400.
If you’ve not seen one of these little beauties, they are the cat’s meow. Basically it’s a RPi4/4Gb built into a keyboard. All the ports are on the back side and it has a massive heatsink that keeps it cool as a cucumber under the most strenuous loads. It’s also small enough to add a trackpad to the right of it, in the lid, so all of the control functions are contained within the confines of the box. This was the final arrangement I settled on.
Since we are talking about the lid section, lets cover what’s there. In addition to the RPi400 and trackpad, there are:
- A pair of 2” speakers, one for the audio of each radio
- Power switch for the RPi400
- 480Gb SSD plugged into the RPi400 that boots it and stores all files. There is no SD card. Also, this is plugged into a USB2 vice USB3 port. There is a specific reason for this, that I’ll cover in part 3, and has to do with the spurious RFI associated with USB3 and its impact on USB mice and GPS dongles
- Support structure to elevate the pi and house the speakers and cabling
- Adjustable thermostat for the internal case fans that keep the radio bodies cool during extended operations
- Recesses for the mics to sit when packed away
Main/Upper Case – Front Cover Plate
The bulk of the gear is housed in the upper case. The front cover plate holds the following:
- Salvaged Laptop Screen
- Control panel for screen
- FT-857D radio head
- FTM-350 radio head
- USB power jacks and 12v jack
- HDMI extension jack (remember the pi has two ports, one goes to the built-in screen and the other is accessible here
- USB extension ports (connects to an internal USB hub)
- Power switches for the screen and accessory power
The front cover is ¼” thick lexan that has been drilled and painted to match the overall look of the build. It is suspended in the box with 3/8” aluminum angle drilled and tapped for black hex head cap screws to give it a military look.
Main/Upper Case – Inside
Inside the box is where all the fun is. In the initial version of GB2 I included an 8AH battery built from 38120 Headway cells. It worked great, but added significant weight to the case and with a limited operating envelope (limited power) I felt that it was better to have the power supply (battery or AC) housed outside the GB for more flexibility. The upside, other than the weight reduction, was that I had more room to spread a few things out and neaten up the arrangement and wiring. So here is the list of the internal items:
- FT-857D radio body
- FTM-350 radio body
- USB hub
- CAT to USB cables for both radios
- 50Amp Anderson panel mount connector
- Cooling fans
- Power distribution terminals
- Fuse block
- RF panel jacks (SO-239 pass throughs)
Main/Upper Case – Outside
The outside of the case, for the most part, doesn’t give much of a clue as to what’s contained inside. As we will see below, the initial goal of maintaining a weather tight package would be compromised by the need for ventilation in the upper case. As you can see in the picture to the right, I also chose to simply bolt straight through the case when mounting various items on the inside.
I have seen quite a few articles and videos that discuss the desire to maintain a storage case “water tight” or some such condition, and on a certain level, depending on your needs, that’s a valid concern. For me, with the operational goals I set for this box, that was not a significant concern.
In the left picture we see one of the ventilation fan grilles along with the 50amp Anderson Power Connector.
In the right picture we see the other vent fan and the antenna ports. The upper is for the FTM-350, the lower 2 lead to the FT-857D: Upper – VHF/UHF and lower – HF
Issues, Problems, Pitfalls, & a Part 3
As you might have gathered while reading these first two posts, not everything was peaches and cream during either of these builds. Rather than being discouragements, each has been a lesson learned and a challenge to overcome. To me, that is the fun of DIY. However, if I’m going to be a good host I think it best to at least give you a heads up on some of the issues I dealt with and how I dealt with them. But to be fair, this installment has already been a long read and so I’ll cover them in the 3rd and final post to give them the attention they deserve. So until next time….
Before you go, I thought I would give you a rundown of the parts I bought for GB1 and GB2 is case you’re interested for your own build. Where possible I’ve provided links to where I got the item. As noted on the home page, I’m an Amazon Associate and as such, I earn from qualifying purchases when that link leads to the Amazon store. It costs you nothing extra and I get a little bit that helps support the site. Thank you in advance.