This Throwback Thursday, we go back to spring 2008, for a little bit of broadcasting history in the making. On May 5th of ’08, a camera crew from YourTV Peterborough (then known as TVCogeco) was present at the transmitter site of radio station CKPT(AM) Peterborough, during the station’s final moments of broadcasting at 1420 kHz on the AM band. CTVglobemedia, CKPT’s parent company at the time, had received CRTC approval in 2007 to convert the station from AM to FM, and its FM signal, which signed on in early 2008 at 99.3 FM, was live in May ’08 as “Energy 99.3”, with AM & FM simulcasting during the approximately three-month transition (standard procedure for most AM-to-FM conversions in Canada), and shortly after 1420 signed off, CKPT-FM moved two spaces up the dial, to its present frequency, 99.7 – the change was required due to interference involving CKPT-FM and Peterborough’s CBC Radio One signal, CBCP-FM 98.7.
About a month after the AM signal went dark, TVCogeco Peterborough posted, on YouTube, this nearly ten-minute clip of raw video from the CKPT AM transmitter site on the west side of Crowley Line, about a mile south of the Peterborough Bypass and the south end industrial park – the transmitter and related equipment were in an old farmhouse on the property. On hand for the end of CKPT AM were long-time chief engineer Ed Crompton and CTV Kawarthas (CKPT/CKQM/CKLY) general manager Steve Fawcett, who flicked the switch off for the final time on the station’s Canadian-made, solid-state 10,000 watt Nautel AMPFET transmitter, ending CKPT’s nearly fifty-year run on the AM band (1959-2008). As you’ll hear toward the end of the video, the very last song to air on CKPT AM was the then-current Daughtry hit “Feels Like Tonight”, and Crompton & Fawcett agreed to “shut ‘er down” at the end of the song, rather than abruptly cut it off.
Radio people: take a peek at the equipment rack just over five minutes into the video… notable components include an Orban Optimod 9100B audio processor (the gold standard for AM audio processing), an older CBS Labs Volumax 4000A processor, some kind of McCurdy product, and a Gentner VRC-2000 remote control/monitoring unit, which may have been, among other things, the device that automatically switched 1420 back and forth between its daytime and nighttime parameters – CKPT was licensed for 10,000 watts day and 5,000 watts night, with different coverage patterns for day and night operations.
Watch what Crompton does at about the six-minute mark… he’s inserting a fluorescent light tube into one of the cabinets for CKPT’s antenna phasor, the thing that distributed the 1420 signal among the station’s four towers, and shaped the signal’s coverage area with specific settings for each tower’s RF feed. There was enough RF energy inside the phasor to make the fluorescent tube light up, without an electricity source connected to the tube.
Remember – AM radio towers (“vertical radiators”) are always energized or “hot” when on the air… the entire tower is a live antenna, insulated from the ground by a small ceramic insulator at the bottom of the tower, and touching a “hot” tower when you’re standing on the ground could give you pretty bad RF burns or even kill you. As for FM or TV, the towers themselves are not energized, but the antennas attached to the tower are “hot” when they’re live, unless they are receive antennas and not transmit antennas.
As for CKPT-FM, recently rebranded as “Move 99.7”, its signal is transmitted from Green Hill, well inside the city proper at the Sherbrooke Street curve, on a tower that previously held the transmit antenna of co-owned CKQM-FM (105.1), which now transmits from the CHEX TV tower on Television Road. CKPT-FM shares an antenna with competitor CKRU-FM (100.5), the successor of Peterborough’s first radio station, CHEX(AM), which launched in 1942 and also converted to FM in the late 2000s, not long after CKPT made the switch.
Next Throwback Thursday, I’ll take you back to 1990 for some wild and wacky behind-the-scenes TV announcing action… stay tuned!