"Intruder Signal" on 40 Meters Disappears
 A September 9 spectrogram of the 7238 kHz "intruder" signal
from VE6JY. The signal has since disappeared. |
NEWINGTON, CT, Sep 17, 2004--The odd and unidentified signal that had been reported showing up on the 40-meter
phone band on or about 7238 kHz has disappeared just as mysteriously as it
arrived earlier this summer. Numerous amateurs in the western US and Canada had reported hearing the signal over a period of a few weeks.
The
FCC's High Frequency Direction Finding Facility in Maryland, which had narrowed
down the signal's source as somewhere east of Prescott, Arizona, was unable to
hear it at all during the day and evening watches on September 16. Earlier FCC
monitoring had indicated the "buzz" was centered on 7238.1 kHz with a bandwidth
of about 1 kHz and consisted of series of discrete signals spaced at about 90 Hz
apart.
According
to an FCC HFDF staff member, a radio amateur in Camp Verde, Arizona, who had
reported hearing the signal at nearly 40 dB over S9 a week earlier said it
suddenly disappeared, and no one in that area has heard it since. The FCC said
the amateur had indicated the signal's presence had generated a lot of
discussion on a local repeater. The FCC offered no firm opinion on the signal's
source.
CLICK HERE to hear an audio clip of the "mystery"
signal in the vicinity of 7238 kHz as heard at the QTH of VE6JY in Alberta: [00:20 MP3 file] |
|
Don
Moman, VE6JY, in Alberta, took a couple of spectrograms of the signal. Bob Gonsett, W6VR, reported that engineers at Communications General Corp (CGC) looked at the
intruder September 6 found "several close-spaced CW carriers."
The 7238 kHz signal is not the only apparent intruder
reported on 40 meters. Bob Reynolds, KD5PSH, in New Mexico, has told ARRL that
he still hears--or recently has heard--signals at approximately 7.020, 7.077,
7133, 7126, 7170 and 7246 kHz. He says the signals resemble the one that had
been heard on 7238 earlier in the month, which he described as "a powerful
signal with a mix of tones."
Stations
with reports on these or other unidentified signals in the amateur bands should
send them via e-mail to International Amateur
Radio Union Region 2 Monitoring System Liaison Chuck Skolaut, K0BOG, cskolaut@arrl.org.
Page last modified: 02:22 PM, 17 Sep 2004 ET
Page author: awextra@arrl.org
Copyright © 2004, American Radio Relay League, Inc. All Rights Reserved.
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