LITTLETON (DENVER), COLORADO
In 2006 and 2007 NRC Broadcasting moved the 4-tower directional array for AM-1510 (KCKK, formerly KYOL) from a site south of the south Denver suburb of Littleton to a new site east of the north Denver suburb of Thornton. This represented a physical move of 23 miles (36 km) to the north. |
09/05/2006 |
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This view looking east shows the new bases for towers #3 (near) and #4 (far). Note that the base for tower #4 is elevated about 6 feet due to the fact that it is located in a lower elevation for the flood-plain of the South Platte River. The antenna tuning unit (ATU) building next to this tower will also be elevated when it is installed.
The pipes extending from the ground to the left of the tower bases contain the feedline coax, antenna phase monitor coax, a copper ground strap that interconnects all of the towers plus the transmitter building, the pattern switching control lines, and AC power. The ATU buildings will be placed directly over these pipes and the cables will enter those buildings through the floor. |
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| The new transmitter building under construction. It is located in the center of the array but is offset so that it is not directly between the towers. It is all metal construction and heavily air conditioned. |
10/30/2006 |
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| This view shows the base for tower #2 as the ground radial counterpoise system is being installed. Note the heavy copper pipe surrounding the tower base. The ground straps from the tower base and from the ATU building are soldered to this pipe. Then each of the 240 copper radial wires is soldered to the pipe. The towers were each equipped with two sets of radial wires. The radials in this photo are actually the secondary set which were installed before the primary set. There are 120 of these radials and they are each about 30 feet in length. They terminate in a solder joint to another piece of copper pipe that completely encircles the tower base at that distance. If you follow the radial wires in the photo you can see where they connect to the outer copper pipe just visible at the top of the photo. This set of secondary radials effectively creates a 30 foot diameter ground screen under the base of each tower. Another 120 primary radials will then be installed over and between these. The primary radials will each extend to about 165 feet from the tower base. The outer ends of the primary radials are not terminated. When completed the entire counterpoise system will be covered with a 3 inch deep layer of dirt. The complete counterpoise system contains about 95,000 feet of copper wire. |
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| A closer view of the radials soldered to the copper pipe surrounding the base of the tower. Also note one of the ground straps from the tower base coming in from the left. |
03/06/2007 |
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| The towers have now been erected by Skyline Towers. This is a scenic picture of tower #2 looking west from the door of the transmitter building at sunset. |
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This is the Harris 3DX-50 primary transmitter. It is capable of producing 50kw and also has digital capability.
The backup transmitter is a Harris DX-10 (10kw). |
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| This is the phasor cabinet in the transmitter building. This equipment determines how much power is fed to each antenna tower and at what phase in relationship to the other towers. That is how the directional patterns are produced. The left side of this unit adjusts the day pattern and the right side adjusts the night pattern. The dials with the white background are the impedance bridge. |
08/18/2007 |
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| Here is a view of the array looking west with tower #4 in the foreground and the transmitter building visible in the background. Notice that the #4 tower base and ATU building are both elevated because of the flood potential at that end of the array. |
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The four ATU buildings located at the base of each tower are fully enclosed, all metal, weatherproof, walk-in units. This is a view of the major components looking through the doorway of tower #2. Tower #2 is the reference tower in the directional array.
In this photo the coax feed from the transmitter building can be seen coming in from the floor at the bottom center of the photo. The RF passes through the antenna tuning system and exits out to the tower on the heavy copper feedline at the far right side of the photo. Also visible in the upper right are the two transformers that read antenna current. One is for local use in the ATU building and the other feeds back to a phase monitor in the transmitter building. These eliminated the need for the tower mounted sample loops that are seen on some DA installations. There is actually another set of tuning components in ATU #2 directly above this set that is not visible in this photo. (see next photo) |
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This is the non-directional tuning system for tower #2 prior to installation in the ATU building. This circuit is used if tower #2 needs to be operated in the non-directional (ND) mode while work is being done on the other towers in the array. During the move from the old site to the new site tower #2 was operated in the ND mode for several weeks while the ATU components that were common to both the old and the new sites were being moved and reinstalled.
Tower #3 has also been equipped with dual tuning components. Through manual switching tower #3 could also be used in ND mode if tower #2 was not available. |
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Please click on NEXT PAGE to see page #2 in this series. |
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