CIRCUITRY WITHOUT CIRCUIT BOARDS

(This page is for Dennison - thanks for the question.)

The trick is an easy way to make a socket on the end of 24 guage copper wire. I use the wire   from multiple conductor telephone cable. It's readily available because it is currently being replaced with fiber optic cable. It also provides a source of rich color (for wire at least). As a rule, Ma Bell's wire is not tinned but if you use clean stuff and solder carefully it works fine. It doesn't hurt to use a little extra rosin flux on your solder joints, and a thermal stripper is a good idea to protect against nicking the wire.

All you need is a pin vise that will hold a piece of 20ga(.032in) spring wire:
The slit in the vise jaws holds the copper wire, and about five turns around the spring wire mandrel makes a perfect solder cup for a DIP pin. If you build a computer this way, the prospect of wiring each pin can be daunting and it takes some practice to get the rhythm of making the coil.  

My Grandmother used to make lace and it fascinated me to see her doing this complicated series of knots while at the same time carrying on a conversation and paying attention to all sorts of things. She told me that she could see her mood in the finished lace. I think making circuitry can be like making lace - given the right rhythm. NASA is probably not interested in this kind of speculation.

The connection to the IC pin is strong and reliable, and can be taken apart quite easily with a solder sucker. It's open to revision at anytime.  By changing the mandrel in the pin vise you can make different size sockets for all kinds of components, nodes, and splices. The insulation on the wire melts quite easily, so solder carefully and quickly. If two wires are pressing together near a solder joint it is possible that the insulation will melt and cause a short that is very difficult to see, but easy to avoid if you're vigilant.

Design engineers, with their characteristic tendency for romantic metaphor, call this kind of wiring a 'rat's nest'. It's probably not a useful way to make production electronics because S/N ratios are not predictable with wire running all over the place.  Freedom from the circuit board grid does let you make your circuits in any shape, and eliminates all the nasty etching chemistry. I have some instruments built this way that have been working for more than twenty years, so I can vouch for the method's reliability. I haven't done it, but I think it could be interesting to see what happens when high-frequency circuitry is wired this way.

A cork board makes a good base to work on. You can use thumb tacks and pins to hold things together for soldering, and I have found small bags of lead shot handy for weights to keep things in place.

The circuitry gets to be like doileys (a new name for modular units) that add together electronically; they're quite tough and easy to handle if you make them carefully. Strategic binding and a drop of glue here and there (acrylic medium works well) makes them even tougher, but remember it is good to be able to take them apart.

I would like to see the walls and ceiling of a whole room covered with functioning circuitry made this way. When you do it, please send me a picture.


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