Good information as always, Bryan. Just a little fine-tuning on the dates.LAPD was originally on medium wave just above the AM broadcast band and moved to VHF (I believe) in the 40s, then around 81-82 started moving to UHF. Only uniformed divisions and patrol officers were on UHF at first, detectives were still on VHF so the decision was made to simulcast Air/K9 on VHF to keep them in the loop. It is my understanding once the move to UHF was complete, the VHF side of Air/K9 was allowed to stay on-air for nostalgic purposes until the transmitter failed and was too expensive to repair.
.When LAPD went to UHF in the early 80s with their 8-channel MX-350s, they only had 18 frequency pairs to work with: 12 dispatch pairs (3 per bureau); 4 tac frequencies (1 per bureau), and the emergency "trigger" frequency 507.2625. Metro Div had 506.8375 to itself
That makes sense, and I used to sometimes just listen to Tact 1 for the hot-shots and avoid all the routine calls on the regular frequencies.So the Air, K9, and many other citywide units continued to keep a watch on "hot-shot" Tac 1, 154.83. Reason behind that, which went back to about 1974, was so those guys could keep one of their radios parked on that frequency no matter where they were and hear hot calls, or requests for their services, from anywhere in the city.