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Friday, December 20, 2013

Christmas Eve Fessenden Memorial Broadcast on 486 KHz

Imagine it is Christmas Eve, 1906 and you are on the air, listening to the harsh buzz of Ol' Spark Morse Code.  Suddenly, in the headphones you hear a human voice and music.

Brian Justin  has set up an experimental station that recaptures that magical "birth of radio telephony" moment.   He will be on the air this Christmas Eve, Christmas Day and New Year's day.   Here is what W4DEX heard during last year's event:

http://www.w4dex.com/500khz/wf9xih/wf9xih_24dec11.mp3


Experimenter to Honor Early Wireless Pioneers with Longwave Transmissions

              Fessenden
As he has over the past several years, Brian Justin, WA1ZMS/4 -- as experimental station WG2XFQ -- will transmit voice and music on 486 kHz on Christmas Eve and Christmas Day and again on New Year's Eve and New Year's Day. Transmissions will begin at 0001 UTC and end at 2359 UTC. Justin, who may be better known for his microwave exploits on ham radio, will use an AM audio loop modulating his vintage-style, homebrew transmitter to honor Reginald Fessenden's Christmas Eve 1906 AM voice transmission.
WA1ZMS constructed his MOPA transmitter from 1920s-vintage components. [Brian Justin, WA1ZMS, photo]
"While his original transmissions used a set of carbon microphones in the antenna lead to modulate the signal," Justin explained, "WG2XFQ will be utilizing true Heising modulation in honor of Raymond Heising, who developed this early form of amplitude modulation during World War I.Justin constructed his 5 W master oscillator power amplifier (MOPA) transmitter using 1920s-vintage components. He said a modern 500 W FET linear amplifier allows him to meet his WG2XFQ ERP limit of 20 W. An RF engineer, Justin collects pre-1920 wireless gear and has a World War I Heising-modulated aircraft transmitter he's planning to restore. Justin was an active participant in the ARRL's WD2XSH 600 meter experimental project.

(From the ARRL Newsletter)

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4 comments:

  1. Thank you for keeping a "light in the window" for one of the most uh-heralded heroes of "wireless broadcast."

    Reginald Aubrey Fessenden was truly one of the prodigious inventors of the radio pioneering days.

    Ken Daidone
    N2KJD

    ReplyDelete
  2. I wish I had a receiver for that frequency... Garrison Keillor mentioned Fessenden on NPR this morning. So maybe the old boy is making a bit of a come-back! 73 Bill

    ReplyDelete
  3. I would think there are more receivers in hobbyist hands today that tune that frequency than in the past. Unless there's a gap around 455KHz.

    I never had a low frequency receiver. A friend's father in 1970 had one of those cheap multiband portables that did longwave and had a rotatable antenna. But generally you needed a surplus receiver or a converter. Though, that Heathkit general coverage receiver with the two-crystal filter at about 1680KHz did do long wave.

    But they digitally synthesized receivers I've bought new and used in recent years all do longwave. The coverage varies, but that has to put a lot of longwave receivers into the public's hands.

    Of course, the only thing I've heard on longwave with the built-in loop is the local airport, longwave beacons still operating.

    Michael

    ReplyDelete
  4. I got my Sony portable out and it tuned to 486. I couldn't hear anything with the whip antenna, and didn't have time to rig anything else. If I get free around New Year's, I'll try again -- maybe use a kite to lift an antenna up there...

    ReplyDelete

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