[QCWA] KDKA and BIll Miller, K4MM (SK)

[Richard Rucker]

On the QCWA Vic Clark Chapter 91's website, there's a folder of 
downloadable files.  You can get to it by clicking on this address:

           <http://homepage.mac.com/rrucker/FileSharing24.html>

Once there, drill down through these folders:

   biographies of chapter members >> Silent Keys >> Bill Miller, K4MM >> 
  Bill Miller's own story.rtf

This file in Rich Text Format (RTF) is an "as told to" biography 
prepared from several discussions that Bill and I had during 1999, the 
year before he died.  This vignette seems appropriate to the current 
discussion of KDKA:


Pittsburgh, PA, March 1939 - 1940
Broadcast Engineer at KDKA

After graduating from Keystone, I got a job as a broadcast engineer 
with KDKA in Pittsburgh. KDKA was the first commercial AM broadcast 
station in the world. Its transmitting station and antenna site were 
first located 32 miles northeast of Pittsburgh at Saxonburg, PA, but 
that location turned out to have a problem. At night, part of the 
radiated signal was reflected from the ionosphere and returned to earth 
in the coverage area out of phase, thus attenuating the ground wave 
signal intended to serve Pittsburgh.

To solve this “self-fading”problem, a new plant was built at Allison 
Park, closer to the more heavily populated areas of Pittsburgh. I was 
the engineer who signed off the Saxonburg station after its last 
broadcast . The new antenna served KDKA until 1994, when yet another 
new antenna was built. The toppling of the older antenna, and the 
design and building of the new one, is a story that Bix Bixby, W4BIX, 
told at the January 1997 meeting of QCWA Chapter 91.

KDKA had a 50-kilowatt transmitter and antenna for the commercial AM 
broadcast band and five or six short wave transmitters and antennas for 
international broadcasting to overseas markets on four or five 
frequencies. The short-wave station, originally W8XK, then WPIT, 
carried programs prepared by the White Network. The White Network and 
WPIT became part of Voice of America’s short-wave network during WW II.

Before the war, there were three broadcast networks: Red, White, and 
Blue. After the war, the Red network became the CBS network, and the 
Blue became the NBC network. KDKA was part of the Blue network and so 
became an NBC station.

The transmitting plant for KDKA was an interesting one. We had a number 
of 23-v alternators to heat the filaments in all those tubes, plus six 
3000-v supplies to provide screen and grid bias, but we had only one 
high-voltage supply for the plate circuits. That plate supply obtained 
its power from a three-phase circuit with a mercury-arc rectifier in 
each phase. These were huge rectifiers, each sitting in its own tank of 
cooling oil, so you didn’t just pull one out and replace it with 
another. Rather, a fourth rectifier was wired in to automatically pick 
up the load should one of the other three fail. The transmitters were 
water-cooled, so there was a big cooling pond outside. In the 
wintertime you could see steam rising off the pond.

On one of the last days of broadcasting from the Saxonburg site, a 
football game was scheduled for broadcast. It was a holiday, so a large 
listening audience was expected. We communicated between the 
transmitting site and the studio in Pittsburgh using Morse code, the 
keyed signal being multiplexed onto the audio programming feed coming 
to us from the studio.

Well, the studio sent me a message to devote every transmitter I could 
to that game. So I cranked up all of WPIT’s eight short-wave 
transmitters and KDKA’s 50-kilowatt main broadcast transmitter for the 
duration.

Herb Irving, the Chief Engineer, drove down to Allison Park to check on 
progress there and then dropped by the Saxonburg site on his way home. 
The latter facility was built in the shape of a “T”, and the plate 
supply controls were located at the center. Herb walked up the ramp and 
checked on the loads being placed on that supply. As he came down the 
ramp, he said, “Call me when the game’s over.”

After the game, he drove back to help me shut the station down. After 
it was all over, he told me: “You set a record, buddy. Those four 
rectifiers have been in there for 25 years. This is the first time that 
any one of them has ever blown!”