Building my fourth drive case using an old Civil Defense Radiation Fallout Meter. Here are links to numbers one, two, and pics of number three can be seen at the end of #2.

Anyway, decided to document the construction of one of these as I build #4. This will be a USB 2.0/firewire combo case supporting pretty much any 3.5" hard drive out there. I'm running #2 with a 160GB drive and have had everything from a 6.4GB drive to a 200GB WD JB in that one. #1 has a 30GB Western Digital, it also has the slowest bridge board so it gets used much less. #3 is off to its new owner.

And here we go.

My starting point, a mid 60's Civil Defense Fallout Radiation Meter. This is a CDV-715 made by Landers, Frary, and Clark, but the same basic design was made by a few other makers. There are many variations. In front of the meter is a slim 80mm fan which will be run at 7 volts, the atomic fangrill, a blue LED, and the original yellow carry strap.

A shot of the guts as I start disassembly. The large silver cylinder is an ion chamber, PCB and battery holder on the right.

Inside of the lower hal showing the schematic. See the black square? it's a piece of foam that holds the battery in place. It will be reused later.

Ion chamber removed, I have a few of those laying around if anyone can think of a use.

Knobs have been removed, the electronics on this one differ from my original two so I have to lose the knobs for now to get everything apart.

All electronics removed, good view of the back of the guage.

The case marked for the fan as well as the drive mounting holes.

That's all I've got for now. Waiting on delivery of the bridge board for this one. Going to drill the holes and cut for the fan in the meantime.


Fan hole has been cut, mounting holes for fan and drive have been drilled. Feet "installed".

Bottom, showing temporary installation of fan to check the fit. Also shows the rubber feet, which keep it up high enough for the fan to get some air, and the drive mount screws.

Internal view, drive mount test. You can see one of the rubber pads I saved, it has been cut in half and acts as a vibration damper. Also keeps the screws from being tightened too much.

Bottom of the meter's top, the legs have been removed in order for the top to fit with a drive installed.

Still waiting on the bridge board, it'll be here Monday sometime. That means I can't really go any further.

I will probably get the knobs mounted, though. Just a shame that the design has changed from the first meters so the knobs will be permanently mounted on this one.


Knobs installed. Been using a screw or bolt, glued into the hole, then the knob is either fastened using it's set screws or a combo of set screws and a dab of glue. If I keep making these I'll be looking at making the knobs control power or maybe fan speed. We'll see.


Got the bridge board today. Not quite what I wanted, but it'll work. What I don't like is the flimsy wiring used for the LEDs, so I'll be replacing that with something sturdier. This board actually has hookups for two power LEDs and the activity LED. Only one power LED will be used.

I also scribed the markings for the ports on the case. I'll be trying a different method on this case. Instead of using a rotary tool I'll just be drilling holes and filing the opening to shape. Gives me better control and less chance to really screw things up.


After a couple days off due to a trip out of state, I'm back with a quick update. Got the port cutouts done and mounted the bridge board. Cutouts were done by drilling and filing, took a couple hours and turned out pretty good.

Board was mounted using a foam pad and sparse amounts of glue. That way things can be easily removed if there's a problem.

Next up is to do all the wiring. I need to make new cables for the guage and LED hookups, and hook the fan up.


And as an update on this one, it's been finished but "transferred" to my uses. First, the guage on the meter has been damaged, so the needle no longer moves. Second, the bridge board runs a stupid activty LED setup that I can't use for a production meter. It always has the LED running and flashes when there's activity. With these guages that means the needle would always be pegged. What I've done now is just hook up the power LED to the activity circuit, so the guage is backlit blue and flashes to show activity. Good enough for my uses, so I'm going to claim this one as my own, get a proper bridge and build another for the guy this one was for. As an upside, this allows me to clean up my USB 2.0 case(#2 above, cleaned up holes and remounted the bridge board) and put that one on the market. Any takers?

I'll update again once I get the proper board, although I'll probably skip a few steps.


And I'm finally back on this one.

New bridge board will be here tomorrow, but until then I have some pics of the new case.

Knobs have been installed.

Have the fan hole cut, fan and grill installed. New big feet installed, too.

Drive mount holes drilled, test drive mounted. Fear the mighty 1.6GB WD, 9 years old and it STILL works great.

A back view of the guage, with a date stamp. This particular one was "made" February 7, 1963.

As I said, the bridge will be here tomorrow, so I'll get the port layout done then and maybe start cutting those. I will be getting the LED placed into the guage and hopefully taking care of the rest of the wiring work.


And this one is complete and ready to ship, but first a few pics.

Got the bridge board yesterday, went right to work getting the case ready. Drilled and filed, then mounted the board. Cut-outs look weird because the ports stick out about 2mm, not flush with the case.

Also got the needle wired up last night.

Today I got everything together. Wired and installed the LED, hooked the fan power into the hard drive molex, etc. The orange blob in the plastic is the original shoulder strap the meter came with and the Eclipse mint tin contains screws and rubber spacers.

And here's a shot of what a retail package would contain. In this case it has power adapter, power cable, USB and firewire cables, driver CD, and the ultra cool original cardboard packaging for the meter itself. Everything fits into that box, too, although some parts are stored within the drive case for shipping.

So that's it on these meters, won't be taking any more pictures when I build the rest. Also looks like I won't be building that many more, my source for meters may have dried up.