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16338RE: [coldwarcomms] High Power Radio

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  • Kam Abbott
    Feb 1, 2010
    • 0 Attachment
      500 kW!


      -----Original Message-----
      From: coldwarcomms@yahoogroups.com [mailto:coldwarcomms@yahoogroups.com]On Behalf Of Radioman390@...
      Sent: January 31, 2010 2:21 AM
      To: coldwarcomms@yahoogroups.com
      Subject: Re: [coldwarcomms] High Power Radio

      Didn't WLW run 250 kW in the past?

      Not to be disregarded is the fact that many AM stations have directional antennas and may
      put a larger equivalent signal in some directions; that is the FCC allowed the power out of the transmitter to
      be 50kW (or whatever), but if the antenna was more efficient in some directions, so be it. This applied
      to the early days of broadcasting (into the early 50s), and later stations on the same frequency had to use
      directional antennas or low power to fit in. Also, because of the AM band's propagation characteristics changing at night
      and at dusk, newer stations might have to change their power or antenna patterns several times on a clock.

      I worked at WQXR AM/FM in New York, and there was a station on our AM frequency(1560) in California that
      had to "protect" us at dusk by running lower power, all having to do with the darkening skies traveling across the country and playing with our signal. They were over 2000 miles away, but WQXR had "grandfathered" coverage rights. This was the true meaning of "Clear Channel" stations (not the company by that name).

      There's also the issue of ground conductivity at AM frequencies. The FCC has maps in its rules showing the ground conductivity across the US, and when determining the "reach" of an AM signal, engineers had to allow for further enhancement or diminution of
      the signal as it traveled. Sea water (salt) had the highest conductivity. Conductivity changes with frequency, so there were a bunch of FCC charts for different frequencies in the technical rules.

      -----Original Message-----
      From: David <wb8foz@...>
      To: coldwarcomms@yahoogroups.com
      Sent: Sun, Jan 31, 2010 12:24 am
      Subject: [coldwarcomms] High Power Radio

      >You can always query the FCC's AM and FM radio databases.

      I suggest using the fccinfo.com front end site; it gives you a number of
      useful tools [Google Earth...] for looking at sites.

      The biggest AM broadcast stations in the US are 50KW day & night. WLW is
      one, as are other famous names from a past era: WJR, WABC, WTAM, KDKA, WGN,

      [Non-text portions of this message have been removed]

      [Non-text portions of this message have been removed]
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