The Emergency Radio Assembly or ERA is housed by a Pelican 1610 rolling air tight case complete with radio, power supply, 4 AGM 7.5amp batteries, 400 watt DC/AC inverter, 2 intake fans, 1 exhaust fan and plenty of flair to impress your friends and family.
The ERA is probably one of the most advanced projects I've constructed in my experience as an Amateur Radio operator. I had previously created the BRA (Briefcase Radio Assembly) which seemed to turn heads; including one of the local OES officers, but it just wasn't enough. Unfortunately the BRA design doesn't include its own batteries, power supply or charger so its use is somewhat limited to its environment. It seemed as though everyone I knew had created their own self-contained emergency radio assemblies that typically only required antennas, I had to create something for myself.
Recently a friend of mine built and designed the TRA (Tool boxed Radio Assembly) which had impressed me substantially with the exception of the lack of room and power supply. The concept of self-contain batteries, the ability to control each power-using device and voltage indicators was extremely appealing and brought forth the urge to build my own.
I had decided that the toolbox, while very practical, would not hold all of the equipment I had desired to install. I wanted to be able to invert both AC/DC and DC/AC, charge the batteries and contain the radio itself in the case rather than mounted on the console as is the design in the TRA. I also wanted to make sure that the container could handle rough environments while closed, the sheer amount of money put into this project would require some level of protection against the elements, mainly, water. With that being said, there is no other alternative than the beloved Pelican cases. Water tight, rugged and this particular model has wheels which as you will see is essential based on the weight of all the equipment this project requires.
Since the ERA was specifically designed for use with RACES/ARES events I decided that there would be no other power option than to use the Anderson Powerpoles system with the exception of one ground buss to make life a little easier with respect to the LED ON/OFF switches. Anderson Powerpoles are very easy to manipulate to get power where you need it and sturdy enough to handle rugged conditions yet modular enough to allow for considerable future expansion or modification. Due to laziness and time constraints I bought a couple of West Mountain RIG Runners and a Super PWR Gate to help with the power distribution and charging of the batteries, all equipped with Anderson Powerpole connections.
After considering the ARES Boom Box project I decided to order a Meanwell enclosed power supply to invert AC/DC at roughly 13.8 volts. Unfortunately on the recommendation of the ARES Boom Box site I ordered the 150 watt 12V supply instead of the 150 watt 13.5V supply. In the specifications both supplies are adjustable to roughly 10% of the rated output voltage, this means that the 12V supply will shut itself down if adjusted past 13.2 volts. I have since ordered the 150 watt 13.5V supply as it should be able to adjust to 13.8V without any problems and will be well within its 10% limit. The Meanwell supplies are rather space efficient but require a little knowledge of 120VAC wiring as there is no direct 110V plug, you have to create your own and in a project of this nature it should be on a switch and fused at around 3 amps for safety. DO NOT touch the 110V leads into the power supply while it is plugged in to the wall, you'll get the shock of your life. I also installed my fans right above the power supply and the batteries to help control overheating in high loads.
The fans are in a dual intake, single exhaust configuration and should provide ample circulation for both the power system and the enclosed radio. The fans are run from a DPDT switch with a 33ohm resister from one contact to the other to support a high and low setting based on temperature, usage and power conservation needs.
The ERA is powered by 4 AGM 7.5amp batteries running in parallel to give a combined output of 30 amps. At 30 amps the unit should be able to run at 1.5 amps per hour for 20 hours straight before dropping to 10.5V. The attached Super Powergate will automatically switch between wall power and battery power to provide for uninterrupted usage and during low use will automatically charge the batteries in a 4 stage process.
Both the console output and the MIC output of the radio are wired directly to the consoles respective CAT5/Phone Leviton jacks. Inside the case are two CAT5e cables with attached RJ45 and RJ11 modular connectors which plug right into the radio.
Because diamond plate is quite expensive, I started out with a standard 1/4" piece of plywood cut to fit the inside area of the pelican case. Fortunately I only made two mistakes on the creation of the console template and I didn't repeat them on the diamond plate. I ended up altering the design several times for both aesthetic reasons and space concerns with respect to the back side wiring. Once the plywood template was done I clamped it to the diamond plate and created each opening right through the holes in the plywood to further prevent any mistakes or tool skips. I cut the diamond plate with my table saw using a 60 tooth carbide saw blade and a can of WD40. If you want to cut aluminum make sure you use a large amount of lubricant like WD40 to keep the blades cool and prevent gumming. When feeding the aluminum in a table saw be very slow and steady it should cut like butter.
On the inside of the case I took another piece of plywood that I cut identically to the console template, leaving the piece of foam lining the bottom that came with the Pelican case I rested the plywood on top to create a shock absorbing buffer. Pelican cases also come with another three layers of pop out foam useful for storing components, I popped out everything accept for the border of the foam and placed the two border layers on top of each other leaving a nice protected rectangle in the center of the case. This created a shock absorbing buffer on all four sides of the case and the inner dimension for the 3/4" plywood borders.
With the plywood borders in place I took 1/8" aluminum L brackets and framed the vertical plywood together leaving a 1 inch lip for the console to sit on. The 1" top was framed in on the top left and right sides with a couple of pieces of square aluminum to mount the equipment rack rails to.
On the inside of the case I took another piece of plywood that I cut identically to the console template, leaving the piece of foam lining the bottom that came with the Pelican case I rested the plywood on top to create a shock absorbing buffer. Pelican cases also come with another three layers of pop out foam useful for storing components, I popped out everything accept for the border of the foam and placed the two border layers on top of each other leaving a nice protected rectangle in the center of the case. This created a shock absorbing buffer on all four sides of the case and the inner dimension for the 3/4" plywood borders.
Check out N4TRB's ARES Boombox!
