High power mobile transmitters were causing trouble with heavy dump trucks and semi-tractors so equipped.
Somewhere in later 1970s, there were semi-trailers available with ABS, but users of CB radios with high-powered amplifiers affected this ABS system by WABCO, is what I recall hearing, as in no effective braking action on trailer when affected by CB radio.
Wiki indicates this type of braking system was available on select passenger car vehicles since about 1971.
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Sidebar
From a
Meritor WABCO manual on trailer brakes
Nov 19, 2015
What is PLC communications?
PLC stands for Power Line Carrier, which is a method used to communicate information by
multiplexing data on the same wire used for the ABS electrical power. PLC communications
convert signal message data to a radio frequency (RF) signal on top of the +12V power line
providing electrical power to the trailer.
Footnote - Anti skid braking was considered years ago for heavy vehicles
On October 11, 1967, the predecessor of NHTSA, the FHWA?s National Highway Safety Bureau, published a notice of its intention to promulgate brake standards for hydraulic and air-braked trucks and buses, and air-braked trailers. (32 FR14279.)......The ??no lockup?? provision was intended to minimize skidding, (page 3 in PDF)