Site of the Week 3/24/2023: CFZM 740/CJBC 860, Toronto

Text and photos by SCOTT FYBUSH

What’s the most historically important AM site in Canada? You could make a very good case that it’s the one the CBC built in Hornby, Ontario in 1937 when it made a big upgrade to the its main Toronto-area signal.

When the CBC was formed a year earlier, it had inherited signals from its railroad-operated predecessors, including Toronto’s CNRT, a “phantom station” that leased a transmitter from one of Toronto’s pioneering commercial stations, CKGW at the Gooderham & Worts brewing company.

The CBC renamed CNRT to CBL and quickly set about building a 50,000-watt transmitter facility suitable for the flagship of a major government broadcaster. It found a site 35 miles northwest of Toronto at Hornby, a crossroads in then-Halton County that allowed it to serve not only Toronto but most of southern Ontario, from London and Kitchener-Waterloo to the west, north to Cottage Country, south into Hamilton and Niagara and east to Kingston.

It built a 645-foot guyed tower and an Art Deco transmitter building that became a showplace for the CBC, open to visitors who could stand behind a railing next to the engineering office and watch engineers in suits and ties maintain the high-powered transmitter that broadcast first at 840 and then, after the NARBA shuffle of 1941, on 740.

The Hornby building grew again after the war, when the CBC took what had been a low-powered fill-in signal for central Toronto, CBY on 1420 (later CJBC on 1010), and expanded it into a full second service to anchor its new Dominion Network for the Toronto area. (The original CBC Radio network, based at CBL, became the “Trans-Canada Network.”)

Because the CBC was both the national broadcaster and the national broadcasting regulator, it could and did assert priority over other commercial broadcasters. CFRB, one of the biggest commercial stations in Toronto, had landed on a Canadian clear channel at 860 after NARBA, but the CBC told it to move to CJBC’s former 1010 frequency so that CJBC could go to 50,000 watts on 860 from Hornby, sharing the tower and transmitter building with CBL.

CFRB tried and failed to fight the downgrade, which landed it on a channel shared with US broadcasters including New York’s WINS (though CFRB was at least eventually able to expand to 50,000 watts itself from a new transmitter site), while the CBC expanded the Hornby building to add more space for a new transmitter for CJBC on 860.

Visitors to this site in the 1950s and beyond would have entered through the main lobby, turned left past the office and stood behind the rails to look out over two pairs of transmission equipment, one on the left for CBL and one at the far end of the room for CJBC.

Over the decades, things became very stable here: with the end of the Dominion network in 1962, CJBC began picking up French-language programming from Montreal, becoming a full-time part of the Radio-Canada French network in 1964 and leaving CBL as the sole English-language CBC station for Toronto. New transmitters replaced the older ones, eventually resulting in two pairs of Continental transmitters, one pair for each station. In 1991, the 1937-vintage tower was replaced with a newer, slightly shorter and skinnier tower designed to last many more decades.

By the 1990s, the CBC was starting to move away from AM radio in most Eastern cities. It had opened new FM relay transmitters in Kingston, Peterborough, Orillia and London to alleviate the need to tune in the more distant 740 signal in those areas. In 1997, the CRTC approved a plan to add another ring of fill-in FM signals in Kitchener-Waterloo (Paris), Penetanguishene and Crystal Beach – and to replace 740 entirely with a new Toronto FM signal, CBLA (99.1).

That FM signal signed on in the spring of 1999, and on the night of June 18, CBL engineering veterans gathered in Hornby to toast the last CBC broadcasts to go out on 740 AM.

While 740 fell temporarily silent, the CBC kept operating the Hornby site for CJBC on 860, It became a landlord a few years later, when the CRTC issued a new commercial license on 740. A small suburban Toronto AM station, CHWO (1250 Oakville), was granted the big 50,000-watt 740 signal, and soon the new “AM 740” boomed out over eastern North America with big band music. Later sold to Toronto broadcast entrepreneur Moses Znaimer, “AM 740” became CFZM, “Zoomer Radio,” shifting to standards, oldies and some talk and continuing to lease broadcast space here from the CBC.

Today, visitors to the site are rare, since it’s not staffed daily the way it was until the turn of the century. But if you’re lucky enough to arrange a tour, as we did for our tower-documenting friend Mike Fitzpatrick, you’ll still see the same basic look to the place: the same Art Deco entrance and office, the same viewing platform, but looking out over an emptier room with much smaller transmitters.

Instead of the old Continentals, CFZM at the back of the room now has a pair of Nautels, a main XR50 and a smaller XR12 for backup. The 1948 expansion to the room still houses CJBC, also with a main XR50 and an older Nautel AMPFET for its backup. Along the front wall, there’s a big display of old newspaper articles and photos and a bunch of storage for CBC transmission equipment that’s headed out to other FM sites around the region.

Most visitors in the heyday of this site wouldn’t have been allowed down the stairs to see the rest of the guts of this big transmitter building, which is a shame – there’s a lot going on underground here! There’s a room off the first landing of the stairs that would once have held the generator (now located outside in a separate enclosure), and several big rooms all the way downstairs that would have held power transformers for the old transmitters and electrical gear. Today, they’re still used for electrical gear, for HVAC and for a big dummy load that can take the output of either station’s transmitter.

As you’d imagine for such an important site owned by a government broadcaster, a fallout shelter went in here in the 1950s. One room of that shelter was repurposed later on as a last-ditch studio, actually used on that final night in 1999 so a CBC announcer could make the last live station ID from the site as the clock hit midnight. It’s since been emptied out, but the rest of the shelter still sits here, complete with bunk beds and civil defense supplies.

(One wall of the shelter is filled with sand, so that any survivors could have dug themselves out to rejoin whatever was left of the world after…. whatever would have happened. Yikes.)

Back up we go, to the 21st century and the closest look we’ve ever had at the tower end of this site. On previous visits in 1999 and again with a National Radio Club convention a few years later, there were too many of us to actually see inside the antenna tuning unit at the tower base.

With just three of us this time (Mike, your editor, and Eli, my infrastructure-obsessed son), we get the full experience, including a chance to try on the light bulb hat that only the most, er, “special” visitors get to don).

And we see (briefly!) just where all this RF goes when it gets out here: separate antenna tuning units for 740 and 860 and the combiners and pass-through filter that allow the tower to be used by both stations or just one if need be.

The base of the new 1991 tower is, of course, a little less impressive than it would have been in 1937, but it’s still one of the few places in North America where there’s more than 50,000 watts of AM going into one tower.

As we walk back to the transmitter building in the August sunshine, we also get to look over at the shorter aux tower on the north end of the property. What was once a very isolated area far from the bustle of Toronto has changed a lot in the last few decades. It’s not just the busy north-south Trafalgar Road corridor just to the west – it’s also two major highways, the busy 401 and the newer 407ETR toll bypass, that intersect just east of the transmitter site.

There’s one more very neat bit of history out on the front lawn: the base insulator of an earlier tower, complete with builder’s plaque. Based on the “May 1939” date on the plaque, I don’t think this came from the original 1937 tower, but rather might have been from an aux or STL tower that has since been replaced.

Thanks to the CBC’s Mick Carberry for the tour!

And don’t miss a big batch of where IDs next Wednesday, over at our sister site, TopHour.com!

Next week: AMs (and a few FMs) in and around Toronto