John, the technology to you probably is as much interest as professional sports is to me.
But the technology was a big part of how we did what we used to do.
Many of the gizmos used were invented by creative engineering people because they didn't exist and if you wanted something, you made it.
The tape delay is one of those.
In order to be able to censor what went out on the air, you needed to be able to have enough time to hit a "dump" button to keep the profanity, libel, etc. off the air.
Most were engineered to dump the offending audio while cutting the phone line the idiot had called in on.
The clever way to do this, before cart machines, was to add a fourth head to an Ampex or other tape machine just ahead of the erase, record play head combo that was standard on professional machines and a few extra tape rollers above the transport deck so an endless loop of tape could be threaded on the machine.
The live audio was recorded normally by the record head but it took the tape loop seven or eight seconds to reach the second playback head, the output of which was sent to the transmitter.
When you heard the offending audio, that feed was cut when you hit the dump button.
Cart machine manufacturers incorporated a similar system in their machines in response to the demand for a machine to do this.
Only problem was with both systems, you had to keep replacing the tape which would wear out in about two hours.
Along came digital delays, the first extremely expensive and clunky and which took a long time to build up the delay period but over time, they were refined and became cheaper.
These are still in use in some facilities these days but computers have replaced "delay machines" in most modern talk studio facilities.