Posted by Roadwolf on February 1, 2014

Here are some of the photos from back in my radio station engineer days. The following are some photos of the CN Tower, behind the scenes.

CN Tower Security Office

This is the CN Tower Security office. The hallway straight ahead is the hallway to the underground delivery area. On the left side along the hallway is the Diesel Generator Room. This photo was taken from a position in front of the maintenance Elevator.

To the right just down the hall is the exit to the stairway which exits out to the patio in Bobbie Rosenfeld Park. The underground delivery area is accessed through a shared underground garage with the 'SkyDome'. It can be seen at the corner of Rees and Bremner Road.

This rack of Sinclair cavity tuners was used to combine many VHF and UHF commercial band radios into a single set of antennas on the outside of the CN Tower. The antennas can be seen above the main pod, attached to the cement structure a hundred or so feet above the pod, facing towards the city. The VE3TWR ham radio site utilizes this antenna system as well. The access door behind the rack, is how you access the crawl space between this level (Level 5) and the curved metal roofing material which the edge walk circles around.

VE3TWR Ham Radio Repeater

In fact, the VE3TWR repeater is directly beside this rack, hidden between it and the access door.

CKFM's old Continental and Collin's tube transmitters.

CKFM's old tube transmitters. One a Continental Electronics and the other a Collins. I believe they were both about 26kw units, but we only ran them at about 20kw.

CKFM's new Nautel solid-state transmitter.

They were likely replaced by this. A Nautel solid state modular FM Transmitter.

The old CKFM equipment rack. You can see this behind the new transmitter in the photo up above.

The modular design of the new Nautel allowed hot swapping of the various power modules. They all fed into a center combiner.

Kind of a crazy looking device, but very slick in my opinion.

It is a mini version of the large combiners up in the CN Tower, which combine all the radio stations up there into one of two antenna feeds. The Marconi CN Tower Combiner.

This combined nine FM stations into a single antenna system. I believe it had the capacity to handle 12 stations. Each station put in about 10 kilowatts to 30 kilowatts depending on their license. The total output of the antenna array had an ERP of about 350,000 watts supposedly.

One of the mechanical COAX switches on the MARCONI combiner system.

A view between a few of the FM Combiners. The copper pipes are actually rigid coaxial 'cables' The large pipes close to the ceiling in the background are about 10 inches wide, and feed the antenna arrays. The equipment in the background is the processing system for the DAB Radio equipment. The other pipes are actually silver clad rigid coaxial pipes.

A closer view of the combiner status board.

The transmitters in this room alone are drawing just a little bit of power. :D As I vaguely recall, there was a small gen set up there, to specifically service the FM Transmitters.

CHUM FM's Collins FM Transmitter and new Nautel Transmitters in background.

CHUM FM also had an old Collins and some new Nautels.

CHFI's CN Tower Equipment Rack

I believe this was CHFI's rack, with some nice PSB monitor speakers. Really overkill for such a loud/high noise environment. But nice none the less.

CHFI's Continental Transmitters

CHFI's Continental Electronics transmitters I believe. Standardization is great.

'Outside' area of Level 5.

This was a view out the access door shown in one of the first photos above. The wall on the right is the wall to the transmitter room, and the metal angled wall is the wall to the outside. You ca kinda see some light between the metal slats and you can definitely feel air moving around up there. It is effectively outside. This is the part of the CN Tower that people walk around with with edge walk.

Various levels of the Main Pod. Image taken from Wikipedia and Edited by me.

So there ya go. A little behind the scenes tour of places you likely don't see very often.

The CN Tower used to have only 2 sets of Elevators until 1989 when they replaced the outside set of stairs with an inside set of stairs. The outside stairs are often not mentioned, but can be seen in the movie Canadian Bacon.