As a followup to my last post on the Sears Tower Antennas, here are a few pictures and some updates. The new antenna is scheduled to go back up next Sunday morning. As prep was being performed on the roof, broadcasters shifted operations to the west tower. That allowed me access to the roof for a few minutes with the people working on the prep. This is a rare occasion due to the RF exposure on the roof.
The EastTowerladder.jpg is the maintenance ladder for the East digital antenna mounts that are accessed on the outside of the tower. The ladder is attached to that assembly.
The eaststeerable.jpg shows our steerable truck pickup microwave in the center of the picture. The antenna is inside the weather housing and rotates via remote control from the studio. It can pickup most of the area except those in the lakefront Grant Park area. For those locations we switch to a horn antenna mounted on the east side of the east tower.
The Easttowerdigant.jpg shows the second digital antenna structure on the east side of the east tower. If you look closely, you will see what appears to be a walkway above the pipe. This is more for ice protection that will fall off the tower above. This prevents damage to the pipe which is actually 6 1/8" hardline coax. Our east facing horn antenna is in the center of the photo.
The last photo, westtowerfull2.jpg, shows our digital main antenna to the left of the tower with a “hat” on top. Again that is ice protection, not an RF assembly. The picture is taken through all of the two way radio antennas mounted on the roof garage. Since all of the broadcasters were on that tower, we could not cross the center line of the roof.
The blue lighting is support for Women’s Cancer Awareness.
You know you are a true tech geek when you end up on top of the Sears tower, and the only pictures you post are the ones of the radio antennae. 
Now that’s not true.
In the view roofviewto NW.jpg you can see the northwest side of the city. For those that know Chicago, the left diagonal street is Milwaukee Ave. and yes it goes all the way to Milwaukee.
The center diagonal is Elston Ave. which starts and ends at Milwaukee. It is a good alternative when the Kennedy Expressway is backed up. The Kennedy is the faint gash that runs under Milwaukee and then between Milwaukee and Elston.
The third street is Clybourn. It ends at what used to be RiverView Amusement Park, at Belmont and Western.
In the Roofviewtoohare.jpg the airport is at the top center of the frame where all the light is. Those that know Chicago, the diagonal street is Grand Ave. In the lower frame it is running nearly east and west and goes all the way to the lake. Then it jogs NW for a while and keeps going right out of the city west. Grand eventually runs into Lake Street in Northlake and becomes US 20 headed for Rockford. The dark strip that runs across the frame just short of the airport is the Forest Preserve that runs on both sides of the DesPlaines River. Anybody flying in from the east to O’Hare flys over the Preserve just before touchdown.
As a Chicagoan, may I just say that I appreciated that you wrote “Sears Tower” and not “Willis Tower”.
-Nick
Ditto
Beautiful.
Whatchootalkinbout, Nick?
Bruce Willis bought the building?
Seriously: Thanks for the update Al, it’s a view that many of us simply would never get.
@Tom Line: What other photos could be of any importance?? 
73,
Don
Whatchootalkinbout, Nick?
Bruce Willis bought the building?
It’s posts like these that prove that chiefdelphi needs a like button.
-Nick
Today’s "learn something new’… had to go look up hardline coax.
Thanks for sharing the shots, Al.
Jason
P.S. Didn’t Bruce Willis *save *the building? I’m sure I saw a documentary about that once.
What? That *wasn’t *a documentary?
While I was on the roof (109th floor) with the crew they were reviewing the pictures for the new install and showed us some of the interconnect hardware. The new antenna is using the 8" hardline coax instead of the 6". It is less lossy at the higher frequencies.
Hey Al, if they’re just going to throw away the 6" stuff, I could use about 170 feet for my tower. Maybe with a Type N adapter for each end…
Don,
I have at least one 6" to N transition but we need it every once in a while, sorry. I don’t know what they expect to do with the abandoned 6". I have heard that the “alley” going up to that pylon is so full, that I would not be able to get through it. That means that the original line is likely buried under a lot of other lines and will remain in place for eternity.
So I guess I can just buy a pair of transitions at Radio Shack? I am also guessing that if I pick it up they will let me have it for free.
(Of course you realize I am just kidding… right?)
Yes you can have it. There are a few problems though…
The line comes in 20 ft. lengths, weighing close to 4 lbs per foot plus flanges,
You will have to get it down in the passenger elevators from 109 which have a ceiling height of 10 ft,
Then you have to get it down the escalator to get to the ground floor,
Then you have to get it through the revolving doors on the street level.
Last time I asked for an N connector at Radio Shack they tried to give me an F to BNC adapter.
How do they get anything else large in or out of the building?
You have to schedule an appointment with the freight elevator operators. There are multiple elevators and the big one has a 13 foot ceiling in the back half of the car and is double wide compared to the other elevators. It also goes from the third sub basement to the top. I forget what the lifting capacity is but I know our high voltage supplies are 800 lbs. each and they came up the elevator. The hard part is, all the elevators are in the core of the building so they face each other or are back to back. This means that the turning radius coming through the elevator lobbies must be calculated for the length of freight you intend to lift and move onto floors. It might require the load to be moved while one end is lifted in the air and the other rides near the floor level. The height of each floor is about 12 feet but there is considerable material hanging from the ceilings in many areas. Finished areas have suspended ceilings that are far shorter than the actual height.
I’d just get it up to the roof and fly it down.