Cal FireWiki info
As of the early 1970s, CDF systems used VHF "high band" (151 MHz repeater/159 MHz mobile) stand-alone repeaters on State of California communications sites. CDF was an early adopter of walkie-talkies (hand-held radios), but the radios did not perform to modern public safety system standards. The systems served their purpose, but were not originally engineered for hand-held coverage because of the enormous operating areas, the difficult terrain, and the lack of infrastructure to support a complex system. Sites had commercial power, but many lacked reliable telephone lines or microwave radio connectivity. In terms of geography, CDF served mostly rural areas and the radio repeater sites to cover these areas were located in remote wildland. Voting was in its infancy and, in CDF repeater systems, was unheard-of. Users understood this and used radios in clever ways. For example, if an engine arriving at a fire could not find a spot where they had a radio path to reach dispatch, they would call another engine that could communicate and ask the staff to relay their message. The unit might see if they could get through by switching to an alternate channel, such as State net, which had repeaters at different sites, and consequently, a different coverage area.