How to Build a Coffee Box
by skrooyoo
The Coffee Box is nothing new or radical. What it is, however, is a merging of two existing boxes into one extremely compact, lightweight, and affordable unit.
Essentially, the Coffee Box combines the functionality of the Beige and Brown Boxes. What this means is that you have a lineman's handset (basically an ordinary telephone adapted to attach to the bare terminals found in telco boxes) with the Brown Box (a device which bridges two separate lines to create a party line of sorts).
What sets the Coffee Box apart from both of these devices is that it not only combines their functionality, but puts it in a package that is usefully small and very cheap. I built mine for less than $25.
Materials
You only need three pieces of equipment:
A Swiss Army or Stanley (X-Acto) Knife: - For parting and paring down wires. I don't recommend a wire stripper as some of the wires we'll be dealing with are quite fine - around about 20-plus gauge, and prone to snapping.
Four Alligator Clips: - Your preferred type of attachment (solder, crimp, or screw) is fine but, from experience, I'd recommend the screw type. More on this later.
One Voice 2000S Mini-Phone: Details of this little gem can be found at www.voice2000s.com/miniphon.htm. Its advantages are outlined in the next section, but you are advised to check this site for its technical specs before proceeding. It'll give you a better idea of why I chose this particular instrument.
The Voice2000S Mini-Phone
I chose this phone for two reasons: firstly, it's cheap - $20 plus tax at Fry's Electronics. Secondly, it's tiny.
One other thing this phone has is twin RJ11 jacks. It doesn't support two lines, but it can quite sufficiently bridge two separate lines to create a party line - more on the potential uses of this further on. It's also packaged with fifteen feet of male-to-male RJ11 cable in the bubble-wrap.
Again, I'll talk about the packaging advantages of this particular item later on.
Construction
Very simple.
Open the packaging and separate it out into its component parts: the phone, the earpiece mic/receiver, and the RJ11 cabling. Grab the RJ11 now, and have the alligator clips and blade ready.
Cut the RJ11 cable in half so that you have about 18 inches of free cable attached to each plug. Discard or squirrel away the remaining cabling for future use. You won't need it here.
Look lengthwise at the RJ11 cabling at the non-plug end, and you'll see two wires inside. Carefully dissect both sets of cabling so that the two internal wires are able to be pulled gently out, then crop off the excess external insulation (usually white). You should now have one red and one green wire exposed.
Again, using your blade, carefully strip about two inches of insulation from the green and red wires. Attach each of them in turn to the four alligator clips you now have laying around.
You're done. You now own the constituent components of a Coffee Box.
Usage
As you would with a Beige Box, connect it up to your favorite terminals in your favorite local telco box, and have fun.
In terms of Brown Boxing - well, I leave it up to your imagination. Wire up a hold switch on one of the jacks and you can do things like, say, connect the Atlanta loops to the L.A. loops. Not that this has ever been done, of course.
And don't forget - its light weight means that the alligator clips can support its own weight when connected to a pair of terminals, which, combined with the earpiece/mic receiver, leave your hands free to do, erm, whatever they need to do. What experience has taught me, though, is that screw-type alligator clips work best - crimps and solders tend to break at the join, whereas screw-types can be fixed "in the field" as it were, with nothing more than a Swiss Army knife.
Limitations
Well, for starters, it has a relatively low Ringer Equivalence Number (REN) of 2.9.
What this means is that the total number of phones on any given line should not exceed that number. If you have the Coffee Box attached to two lines (or one line with two other phones), you have an REN of 3 (Coffee + 1XX-XXXX + 2XX-XXXX), slightly more than it is supposed to be able to handle.
I have quite successfully run it under these conditions for some time now without any trouble - its tolerance limits are pretty good. However, that doesn't mean that you won't have problems.
Therefore, the disclaimer: your actions, your ass. I would also heed the manufacturer's disclaimer as relates to using it in thunder and lightning storms: don't. It really isn't designed to ground out large voltages, and if you do lose a hand, hip, or head as a result... well, that's also your problem, not mine. 'Nuff said.
Credits
2600 and the L.A. 2600 crew most definitely. Shouts to Boogah.
Oh, and as for why it's called a Coffee Box - well, combine beige and brown, and you get something about the same color as coffee and cream. Hey, it's better than the "baby-couldn't-help-it" box!
