[BC] Usefulness of EAS

[Ron Youvan]

RichardBJohnson at comcast.net wrote:

> 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.

   Wrong, WSUN 620 kc/s (5 kW) Saint Petersburg, FL (the first American DA, as WFLA) switched to 640 
kc/s and WDAE 1250 kc/s (5 kW) Tampa, FL (Florida's oldest surviving station) switched to 1240 kc/s 
for CONELRAD operation.  Other stations switching to 640 and 1240 kc/s for the Tampa/Saint 
Petersburg/Clearwater market were in outlaying areas, Lakeland to the East and Pasco county to the 
North and or Manatee county & Sarasota to the South.

   They just changed the unused crystal to 640 or 1240 kc/s and at the appropriate time they 
switched to it.  (I am sure some did not make full power on the wrong frequency.)
(they also had to go non-directional if they were normally directional)

   The point of making a 640 and 1240 in every area was so from the air 640 and 1240 was coming from 
everywhere.  The reason for rotating between station in an area was there was no one place that 640 
or 1240 was continuously  coming from.
   If there were 640 kc/s and or 1240 kc/s stations on the air in any markets they didn't need to 
change anything.  (I don't recal hearing about any.)

-- 
Ron KA4INM