Radio Waves Podcast #153

A few weeks ago I wrote of a news story out of Albuquerque, New Mexico in which a suspect with explosives was seen in the area of a transmitter site for numerous broadcast stations. Had a television station engineer not happen to be in the area and the suspect was able to follow through with his alleged plan, most of the television and FM stations in the area could have been knocked off the air. I mentioned that it might be time to rethink transmitter security.

Reader Anthony Chan of Monterey Park read the story, and it reminded him of something he read in the past. “I am assuming that you are a card-carrying member of SPERDVAC (the Society to Preserve and Encourage Radio Drama, Variety And Comedy), and receive their publication, RadioGram.”

Yes, I am, though I believe I let my membership lapse ... something I must take care of right away. But I digress.

“I have enclosed a reprint of an article from October, 2006 by Mr. Newcomb Weisenberger, recently deceased, who worked at KFI (640 AM) as an engineer for many years. Part of his tenure included the years of World War II; in this article he tells the story of the transmitter being guarded by soldiers with loaded rifles and guard dogs. The rationale was that they KFI and KPO/San Francisco signals were used by US Army Air Force navigators to keep their planes on course to Hawaii.”

It’s true. And one of the more interesting war-related radio stories.

As Weisenberger describes it, there were many in the industry who were curious why there were some strange things going on at KFI.

• Why, with the draft taking so many engineers away, was KFI allowed to keep so many ... and even added to the ranks?

• Why was KFI suddenly on the air all night long with no sponsored programs?

• In addition to the money-losing night-time broadcasts, why was KFI using its full 50,000 watts 24-hours a day when it used to power down at night and sign off completely at midnight? The extra electricity, and the third shift of a full engineering staff must have cost a fortune. And much of the signal was being sent over the ocean where no one was listening.

• Why was the KFI property patrolled by armed US Army riflemen, and why were several 30.06 Springfield rifles with live ammunition kept in the KFI transmitter tube locker?

• Why were there searchlights on the roof, “menacing, vicious guard dogs on the loose all night,” and why did the American flag fly dawn to dusk?

Talking among the engineers soon became guesses, later to become verified facts. Earle C. Anthony, owner of KFI at the time, had received a classified letter from the USAAF requesting -- read: ordering -- him to operate the station at full power 24-hours per day, every day.

According to Weisenberger, “our guesses were right. Mr. Anthony came to us and read words that stated directly that the United States Army Air Forces would be using the signals of KFI 640 and KPO 680 to guide our new military airplanes to Hawaii.”

A newly developed “Direction Finding Device” would be used on the planes to track the signals. Using triangulation, much the same way modern devices use satellites for tracking and navigation -- including the navigation system in your car and on your phone -- the military airman could track the plane’s direction by tuning into the signals and sampling the overlap. 

It worked as long as the signals were reliable, uninterrupted, and carried all the way to Hawaii. Being clear channel stations -- no other station on their frequency -- and operating at full power, that was easy for both KFI and KPO. Both stations probably carried all the way to Japan.

This is just one of the times AM radio helped in the war effort, but it is one of the most fascinating. If anyone has more information I’d love to hear it. I doubt that many who were directly involved are still around, but if you are ... or you are a relative or friend of one and you have a story to tell, please drop me a line.