Spies in Centennial Park (Part II)

I've received a lot of responses about my "Spies In Centennial Park" post from last week. I've learned a lot since then, and though I'd share some of it here...

The 110-acre antenna farm at what's now Santa Ana's Centennial Park was officially known as the Santa Ana Primary Monitoring Station. It was built by the federal government in 1941 to listen to signals being sent from Hamburg, Germany (6,000 miles away) to Hitler's spies in the U.S. Thirty three spies were arrested based on this program.
By the early 1950s, it was operating as one of eight Federal Communications Commission monitoring stations, scattered across the country. Thirteen people worked there in shifts, around the clock. They made sure FCC regulations were being adhered to in our area. But in addition to playing "radio traffic cop," the facility was also recording broadcasts from Russia and other parts of the world.
At the time of a 1952 L.A. Times article about the facility, William J. Hoffert was the engineer in charge and Alfred K. Robinson was the assistant engineer. They couldn't talk about their spy activities, but they said they'd "brought to justice operators of illegal portable radios in local race tracks, located lost planes, and prevented the burning of at least one yacht."
From the same article:
"During World War II, a phyiotherapy outfit in a medical building was found to be doubling as an illicit radio transmitter. Special cunning was required to discover that a clarinet player in a Berlin orchestra broadcasting to this country was varying his tempo to send messages to German agents in America.
"What seemingly is pesky static on a broadcast from England may be something else. What is there to keep a foreign enemy from making recordings of static and broadcasting them on the British program wave length? A Churchill speech might even be used to camoflage coded signals from Stalin."
Brad Weber tipped me off to this article and also told me, "I knew people -- civilians -- who were prominent in the communications and radio field and were allowed to visit the facility prior to the 1950s."
But things seem to have gotten a bit more secretive as the Cold War heated up. Reader CoxPilot relates a story from his childhood, around 1955:
"One time we decided to take out pellet guns out to the river and hunt mice and rats. We parked our bikes at the bottom of the dip in the sand and proceeded to walk west down the river to see what we could find. This placed us parallel with the antennas. Then, suddenly, we were confronted with a couple of men with guns and badges, and were told that we were not to be in that area, and that it would be best if we left. They said they were government guards, not police, and we would not be reported if we didn't return. We never did."
Reader Jim B. related a similar experience from the 1960s, when "a
couple of my friends went up to the gate one day to see if they could take a tour but were told (not in friendly terms either) to leave."
Rich S. wrote that he was told the FCC facility was heavily guarded due to the "threat of war [with the USSR] and possibility of communications takeovers."
Orange County Historical Commission Chairman Don Dobmeier also stopped by and said that local historian Wayne Gibson once told him the Santa Ana monitoring station was "where the Japanese code was broken" during WWII. At some point, I may need to call Mr. Gibson and see if he can tell me more about that particular story.