|Around 10444 kHz to 10514 kHz|
|Around 9428 kHz|
|Around 11000 kHz to 11100 kHz|
|Around 12411 kHz|
This signal consists of a sound similar to that made by a grasshopper or cricket, and has a slower harsher sound than that of the Faders. The signal appears to have some sort of "phase" effect, like that found on old 1960-70's pop records.
The signal will transmit on one frequency, then suddenly appear to drop in volume. Retuning of the receiver however reveals that the signal has jumped up or down the band. The move will be exactly 1, 2, 3, or 4 kHz from the original signal.
The sequence is then repeated, with the signal jumping to either another new sequence, or returning to its original frequency.
The sound of the signal, which is pulsed, does have some resemblance to the old Russian "Woodpecker" signal which caused so much controversy in the 1970's with it's powerful broad-band transmissions across the whole of the short-wave spectrum.
In Europe, try evenings from 1900 UTC.
MYSTERY SOLVED - SIGNAL IDENTIFIED AS IONESPHERIC RESEARCH PROJECT
In October 2000 I received an email from Paul Beaumont in England, who I had been in correspondence with on various radio topics. At the end of the email Paul had added;"Incidentally the 'Grasshopper' sound that you refer to on your website is almost certainly a sample of the Super Dual Auroral Radar Network system recently heard."
Rob suggested looking at the Real-Time Data displays on the website, which allow tracking of the actual frequencies in use.
This gave the conclusive proof I was looking for - the source of "The Grasshopper" signal had been found.
For more information visit the SuperDARN Website.
Additional information can be found at The University of Leicester Radio and Space Physics Group web site. They operate two of the SuperDARN Radars in Finland and Iceland and have a lot more information about how the Radars work./
Be sure to look at Rob Barnes' Real-Time Data Displays.
(Try "Hankasalmi B". When the Applet has loaded Click " Open Connection", Click "Fan Plot"). They are both fascinating and beautiful to observe and will also give you a real-time indication of the frequencies in use.
My sincere thanks to Rob Barnes for his help, and for allowing me to use his information on this page.
Finally, I am most grateful to Paul Beaumont whose sharp detective work solved the source of this mystery signal. Thanks Paul!