I had the opertunity to work in the first headend in America in Pennsylvania and they had some of the first amps they used--a bunch of vacuum tubes in a powersupply size metal container mounted the side of a pole. Believe it or not, they had a bunch of that stuff left over. Unbelieveable what they used to have to work with. I heard the first amps were run off of an extension cord from the nearest costumers garage. Don't know how true that is, but sure sounds alot like now-a-days.
This is CABL.com posting #179113. Tiny Link: cabl.co/mUK5