On 9/20 & 9/21/04 I had the pleasure of teaching my "Hot Tower Safety Awareness" presentation to some of the members of the North Area Technical Rescue team here in the north Denver area. As part of the presentation I made arrangements with KPOF General Manager Jack Pelon (who also has a broadcast engineering background) to bring the classes to the KPOF transmitter site for a tour of the facilities.

This is the KPOF 268 foot tower. It is located on the highest hilltop in the area north of Denver overlooking the entire Denver metro region. This tower was erected in 1977 to replace a nearby four leg self-supporting tower that had been erected in 1935. KPOF is operated by the Pillar of Fire Church and has been on the air in the Denver area since 1928!

That's Mr. Pelon on the left between the tuning shack and the KPOF tower braving the very cold September rain.

Mr. Pelon explains emergency shut-off procedures in the interior of the tuning building.

This is the KPOF main transmitter - a Nautel Ampfet solid state unit with 4 RF amplifier stages rated at a total capacity of 6,000 watts.

KPOF was the first AM in Colorado to run full time IBOC stereo. This is the equipment that processes the audio and generates the IBOC signal.

This is a close-up of the control screen on the IBOC exciter.

This is the Harris MW-5B backup transmitter. This is a tube type unit and is the former main transmitter. The transmitter before this was a Harris MW-5 that is still present but will be donated to another non-profit station in either NM or AK.

When the backup transmitter is in use, KPOF does not use IBOC but does broadcast in Kahn Powerside mode. This is the Kahn Powerside unit in use on the Harris backup transmitter. This is the second generation of Powerside that has been used at this facility.

This is the previous generation of Kahn Powerside that was used at KPOF.

This is the antenna switching unit. At the far left is a 'dummy load' that absorbs the RF power for whichever transmitter is not connected to the antenna. The RF is dissipated as wasted heat. This is used for off-the-air tuning of the transmitter that is connected to it. In the center of the photo is the switching unit itself. It can be operated from remote control as can much of the equipment in the transmitter building. At the lower right in the photo you can see the point where the RF energy exits from the top of the Harris standby transmitter and feeds a coax cable to the antenna switch. Directly behind that is the coax coming from the Nautel transmitter going to the coax switch. Dropping down from the antenna switch is the larger coax that leads to the tuning shack at the base of the tower. This coax runs underground so it is charged with very dry nitrogen to keep it moisture free and prevent arcing.

This is the KPOF mobile IBOC demonstrator. It is equipped with an AM IBOC receiver and is used to demonstrate the IBOC system at various public events.

This is the previous KPOF tower as it was being felled by wrecking crews in 1993. After this tower was replaced by the present KPOF uniform cross-section tower in 1977, it continued to serve public safety and two-way communications users as an antenna platform for another 16 years. The old tower had been equipped with a detuning device so as not to interfere with its nearby replacement. The tower had originally been purchased used from another station in Philadelphia. It was disassembled and transported to Colorado where it was reassembled.

(news photo by Scott Perriman - originally published in the 05/13/93 edition of the Westminster Window)

For more information about KPOF check out their web site at www.kpof.com

©2004 PMG