The Dec. 22 issue of Radio World features our Buyer’s Guide for antennas, RF support and power products. Buyer’s Guide features application stories like this one.
CKNW(AM), a 50 kW station at 980 kHz, is an existing four-tower directional array located near Surrey, to the southeast of Vancouver, British Columbia, Canada.
CKSP, a 600 kHz, 50 kW DA-D, 20 kW DA-N station operated by Sher-E-Punjab, a broadcaster specializing in South Asian news/talk content, was added to the site making use of two of the four towers. It required a diplexed directional antenna system designed and fabricated by Kintronic Labs to facilitate the simultaneous operation of both stations from the CKNW transmitter site.
According to Tom King, president/CEO of Kintronic Labs, project management of the diplexed AM directional antenna system project was conducted by Richard Sondermeyer of G.S.Broadcast Technical Services Ltd. of Mississauga, Ontario. Final commissioning was conducted by Rob Elder, the Kintronic Labs field engineer.
The existing CKNW four-tower array is in the shape of a parallelogram, with two diagonally opposing towers oriented along a north–south line, and the other diagonally opposing towers oriented along a line rotated roughly 50 degrees clockwise from the center of the north–south line.
The NW tower is also the closest to the transmitter building, and its ATU building houses the CKNW power division/phasing networks as well as the tower matching network for this tower. The two towers on the north side of the array are those used for the new 600 kHz system, with the towers on the south side of the array detuned for 600 kHz.
The 600 kHz phasing and matching system was installed in a separate container located south of the CKNW transmitter building. The CKSP matching, filter and detune cabinets were installed in weatherproof housings and mounted on wooden platforms at the base of each of the towers.