[BC] Usefulness of EAS

[RichardBJohnson at comcast.net]

Do not believe Wikipedia. No station -- none, ever switched to 640 or 1240 kc/s for CONELRAD. In the days of kilocycles, there were no instant-tune transmitters. To bring up a transmitter such as a Western Electric 304-A on a new frequency required a group of engineers from Western Electric. The transmitter used custom-wound coils for each frequency and the output amplifier required precise 90-degree networks both at the input and the output to get the peak and carrier stages to operate properly. I know, I maintained one at WDEW. Even the Raytheon RA1000-A required multiple changes to switch frequency. I know, I maintained one at WARE.

Earl Hewingson, the chief engineer of WTYM, who built its 5 kW transmitter from scratch, started in radio in the '20s. He told me how CONELRAD worked. The round-robin transmitter switching was to confuse bombers that used ADF. The idea was to keep everyone off the air except for a few 640 and 1240 kc/s transmitters. This included most of the 640 and 1240 kc/s transmitters, which were warmed up and ready to run.

Upon a coordinated command, the 640 and 1240 kc/s transmitters were shut down and another group were started up. This continued, trying to keep at least one such frequency listenable in all major markets, ignoring the hinterlands.

Stations that were off-the-air, were required to stay off until an all-clear signal was received in plain text from at least two of the CONELRAD stations.

Cheers,
Richard B. Johnson
Book: http://www.AbominableFirebug.com/

----- Original Message -----
From: "Robert Meuser" <robertm at nyc.rr.com>

But that is not how the system worked. There were what were called key 
stations that did indeed have direct lines just as the PEP stations they 
later became still do. Other stations were alerted over the air and by 
telephone. This did not just apply to stations on 640 and 1240. Many 
stations usually on other frequencies switched to one of those 
frequencies and were to operate in round robin fashion so no one station 
was on for an extended period, thus defeating radio direction finders.