Excuses
This is why I haven’t been taking photos or updating my blog this month.
What you are looking at, is the beginning of the telephone exchange I’m designing and building from old GPO components and circuit techniques. I’m designing it from scratch, picking and choosing circuit elements from various telephone exchange designs from the 1930s-50s.
Tonight, I managed to build the first two line circuits (there are enough relays in the image above for four line circuits, but better to start small!) After a little bit of debugging (the connection tabs on the back of those relays are really confusing!) all the bits of wire have the voltages I’m expecting on them! Yay!
Some of my prototyping methods are a bit vintage as well. These are copper coated nails, which are used to make an impromptu wirewrap board. This particular bit of prototyping is the subs-multiple.
The stuff I’ve built doesn’t really do much at the moment (apart from click a bit when you pick up a phone) and the next stage is to build the linefinder. That bit is much more interesting as it spins round and makes nice raspberry noises.
I wonder if my video camera still works
The “copper mails” confused me for a second.
Glad its getting there, and that you havent totaly fallen off the facee of the earth, i enjoy all the photos on your blog, im dreading the day you decide no longer to update…
Rats
Ta for spotting that, I’ve corrected it ;-)