In 1946 several Auckland and Wellington police cars were fitted with modified Gulbransen broadcast band radio receivers set to a frequency of 1680 kHz (just above the AM broadcast band). Medium frequency radio-telephone transmitters, owned by the New Zealand Post Office and located at Musick Point, near Bucklands Beach in Auckland and Tinakori Hill, Wellington were connected by land line to the Central Police Stations.

The transmitter used in Auckland was a Collier and Beale model 142 SW-1 manufactured in New Zealand in 1942. It had a power output of 100 watts and was located at the transmitter site of the Musick Point Memorial Radio station near the present McLeans College in Bucklands Beach. The Musick Point radio station was the main Post Office communication station for Auckland. It included the coast radio station ZLD/Auckland Radio handling marine traffic, and the Aeradio station ZLF for communication with aircraft on trans-Tasman and Pacific routes.

When the police ceased operations on 1680kHz in 1950 the transmitter reverted to it's original function as a backup transmitter for ZLD on the 2MHz marine band, and remained in service until the station was decommissioned in 1993.