On Jan 25, 2020, at 08:52, Paul Nash <p...@nashnetworks.ca> wrote: > > >> >> So, I grew up in South Africa, and one of the more fascinating / >> cooler things I saw was a modem which would get you ~50bps (bps, not >> Kbps) over a single strand of barbed wire -- you'd hammer a largish >> nail into the ground, and clip one alligator[0] clip onto that, and >> another alligator clip onto the barbed wire. Repeat the process on the >> other side (up to ~5km away), plug the modems in, and bits would >> flow... I only saw these used a few times, but always thought they >> were cool…. > > Do you remember anything about the actual type of modem? Or where you > deployed them? > Decades ago, I cobbled together a 20mA current loop interface that may have been an early version of this .. ran a set of Baudot machines (pre-ASCII, upper case & figs only) mostly just to have fun with a set of old ASR 32 teletypes. I used a couple of 500’ spools of zip cord lying on the ground from end to end. Never mind backhoes - it was lawn-mower vulnerable. (However, being flat on the ground seemingly made it less vulnerable to lightning strikes.)
Of course, this was hardly critical infrastructure! Blessings.. Allen
