AM Ground Systems Company

KMOX Ground System Rebuild


Coax Repair

November 2005

We signed a contract from Infinity/CBS  to rebuild the old ailing KMOX ground system and repair a burned 3in coax in the ATU building. The old connector was almost completely burned off of the line.  The first request we received was to splice the burned cable outside the building UNDERGROUND.  I was able to convince KMOX consultants and engineers that the underground splice was not a good idea since flange connectors have an official designation of "Weatherproof" not waterproof.  We eventually had to locate the cables and excavate back approximately 20ft from the ATU building, we then routed the old coax and a new section up thru large conduits into a large NEMA enclosure mounted on a concrete pier.   The splice consists of a pair of right angle flange connectors.  Probably wouldn't be ideal for FM but worked great for high power AM.

The ground system was specified to be 240 half wave (490ft) radials.  We had to locate a large portion of the old radials along fence lines and reconnect into the new ground system.  There was also an area where the new ground system would be shortened and connected to the KMOX standby tower.  This was done by locating the old radials, digging a trench along the fence line exposing the old radials and then installing the new radials and a 2in transverse strap (as between towers in a DA).



Click on a picture to view a larger version.

The backside of the KMOX TX building

KMOX Tower from the driveway behind TX building.

The ground system is complete. The fence and new asphalt is visible.

Across the site

Another shot along the newly paved driveway.

The ground never froze but it got plenty cold enough to freeze casual water.

The gravel along the new asphalt was placed to cover exposed radials that ran across the large rock of the road foundation.

A very nice looking site after all work was complete. The old fence was falling down and the asphalt was pretty ratty.

The NEMA enclosure shown here houses a splice in one of the 3in feed lines to the ATU building. More on the repair later.

Fence grounding as suggested by Jack Sellmeyer and designed by AGSC.

The fence posts had large copper conductors cadwelded to their base and bonded back to the main tower base ground point.

Several 1in copper pipes were installed thru the ATU building for RF grounds. The outside ends were bonded back to the tower base ground point.

The KMOX tower base.

Looking back toward the TX building.

Not exactly KMOX but certainly St. Louis. This is the brick pavement along the Mississippi River below the Arch.

The inside of the tippity top of the Gateway Arch.

Looking down from the top of the Arch.

The new Bush Stadium under construction.

What was left of the old Stadium.

The Capital.

Not a clue...

Looking up at the arch.


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