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1930s Broadcast Stations with Ham Call Signs

Discussion in 'Amplitude Modulation' started by W0RIO, Oct 26, 2021.

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  1. W0RIO

    W0RIO Ham Member QRZ Page

    I found this image of a Zenith radio station tab sheet while looking at antique radios on Craig's List
    and noticed what looked like ham call signs in the second row from the bottom:


    A brief search for one of the stations, W2XDV came up with this:


    A person could spend all day chasing down links for the other stations on the list.

    Can any of the old-timers out there shed some light on the history of commercial/experimental stations with ham
    K0UO likes this.
  2. W7TFO

    W7TFO Premium Subscriber QRZ Page

    K0UO, AC0OB, W0RIO and 1 other person like this.
  3. W1BR

    W1BR Ham Member QRZ Page

    Well, that explains the 60 MHz coverage in some of my ancient wood tombstone radios!
    K0UO likes this.
  4. N1BCG

    N1BCG Ham Member QRZ Page

    N3RYB and K0UO like this.
  5. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    K0UO likes this.
  6. AC0OB

    AC0OB Platinum Subscriber Platinum Subscriber QRZ Page

    Hallicrafters sSX-62A.png
    The Halli SX-62A was one of those receivers designed to receive those "new" bands.
    Last edited: Oct 26, 2021
    K0UO likes this.
  7. K0UO

    K0UO Platinum Subscriber Platinum Subscriber QRZ Page

    Many of the experimental Broadcast stations pre/post-World War II did have a number a number in their call assignment

    And remember the East of Mississippi W Rule and West of Mississippi K rule/ but there were a lot of exceptions to that also.

    Most of the engineers running the stations were hams also at the time. Amateur radio built the Broadcast business

    73 from,
    The K0UO " Rhombic Antenna Farm" 2 miles of wire, I'm In the Air or On the Air daily
  8. AC0OB

    AC0OB Platinum Subscriber Platinum Subscriber QRZ Page

    "...In the United States, the Federal Radio Commission (later to become the Federal Communication Commission) began to consider several technical alternatives to solve these issues in 1932. Their first step was to expand the upper end of the AM band from 1500-1600 kHz. The second move was to authorize radio broadcasting on upper short wave frequencies by authorizing what it called “Apex” stations. The third and most elegant solution was ultimately the invention of Frequency Modulation (FM) by Major Edwin Armstrong and others. FM eventually became the FCC's preferred solution, and it supplanted the previous attempts to create high fidelity, “staticless” radio.

    In 1927, the FRC had decided not to expand the AM broadcast band from 1500-2000 kHz, but to hold these frequencies in reserve for experimental work in broadcasting. In 1932 it created three frequencies to be used by experimental wideband “high fidelity” AM stations — 1530, 1550 and 1570 kHz. Because of the wider spacing between these three channels compared to the standard broadcast (AM) band, stations on those frequencies were able to operate with an audio frequency response up to 10 kHz instead of the usual 5 kHz..."

    This, in my view, was the first major screwup by the FRC/FCC to improve AM. If they had authorized the audio bandwidth to 15kHz, as they had for FM, and had allowed for increased TPO's with greater station separation, then I don't think the AM broadcast band would be in the situation it is in now.

    As of now, the FM translators many AM stations have are now the primary point of focus for station ID's.

    K0UO likes this.
  9. W1BR

    W1BR Ham Member QRZ Page

    When was the AM band ever restricted to 5 kHz, except for those running Ibiquity HD garbage? I know it was cut back a few decades ago, but as I recall the BW was still in the 1o kHz range?
  10. W7UUU

    W7UUU Principal Moderator Lifetime Member 133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    I have one of those beasts that was all but destroyed in my shack fire last year... 100 pounds of boat anchor glory!
    Wonderful old receiver - each band lights up on the dial as you rotate the band switch. It was sad to see mine die in the fire


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