KPFK Transmitter Project
April-June, 2002

June 7, 2002: Electrical work is proceeding, and by mid-June, is nearly complete. The roof now has an ice shield, the new electrical switch gear has been installed, and the new closed Delta high voltage system has been installed under the pavement on Red Box Road. The following pictures show some of what was involved.

The KPFK engineers were on site at 6:15 AM in anticipation of a 7:00 AM switch-over. But Edison was late, and it took another two hours for them to kill the power and work inside the street vault. We scrambled and got KPFK back on after hooking up the emergency generator. KPFK was off again at 2:00 PM when we were given the green light to return to Edison power. Timing was dependent on the safety of the Edison crew, which was the first priority.

Getting organized at 7:00 AM. Edison has now upgraded the service to a closed-delta, a big improvement over the 40 year-old open delta system.

Edison "popping the cork" on the 4,000 volt street vault

Pulling the new high-voltage cables

Moving the new (third) transformer into place

Yes, the power to the vault was off during this process!
Connecting in the third transformer under the street.

While the power was off, KPFK stayed on the air using this generator from United Rentals.

Part of the new high capacity switch gear.

The new Edison termination on the KPFK building

More detail of the new electrical switchgear

The contrast between the old interior electrical switches (left) and the new (right) is kind of obvious.

After cut-over, the fire damage to the old box was obvious.
Fire damage in the old breaker box

New and capable of the load

Plenty of capacity is now built-in to the system.

Now that the electrical system is up to the job, what remains is to put in place the transmitter input and output connections. This might sound easy, but it is a very difficult process, due to the size and scale of the connections involved. That part of the project can be found here.

KPFK operates at 90.7 Mhz with 112,000 watts, 5900 feet above sea level and 5600 feet above Los Angeles, California.

For more about Mt. Wilson, check out my pages about the mountain here.

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© 2002 Broadcast Engineering Services of Bonny Doon