Mystery Signals of the Short Wave

Dedicated to the more unusual, strange, bizarre and apparently meaningless signals on the short wave bands !

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"Yosemite Sam"

A bizarre and puzzling transmission heard in 2004 / 2005

Yosemite Sam

In December 2004, shortly before Christmas I received an email from a listener in the USA reporting a signal on 3700kHz that was being heard all over the USA at good strength.   Attached to the email was a small sound sample of the signal, consisting of a short data burst followed by a piece of garbled speech and being sent every 50 seconds.

Other monitors had heard the signal too, which had first been heard on Sunday 19 Dec 2004. It was established that the transmission was cycling through four frequencies, one every ten seconds from low to high continuously, and was being transmitted in DSB, double sideband mode.

The frequencies used were; 3700 - 4300 - 6500 - 10500kHz.

Though signal strength here in South East England was poor, reception was possible and was best heard on 6500kHz.   Monitors in the USA reported much stronger signals and were able to confirm that the speech was a clip featuring the voice of Yosemite Sam saying "...varmint - I'm a going to blow you to smithereenies", which is an extract from the 1949 Bugs Bunny Cartoon "Bunker Hill Bunny"

  "Yosemite Sam" - (Sample recorded in S.E. England)  (14 kb)

  Original Clip from "Bunker Hill Bunny" Cartoon  (21 kb)

Transmissions ceased on Thursday evening December 23, and after a quiet Christmas were heard again on 14 Jan 2005 - but the frequency use had changed. Now the international time frequencies of 10 - 15 & 20MHz were being used as well.

The use of 3700kHz was not a wise choice, since it is in the middle of the Amateur Radio 80 metre band, and its use had attracted the attention of two licenced hams living in New Mexico, Mike Stark (WA5OIP) and Mike Langner (K5MGR).

The signals were particularly strong in New Mexico and on Wednesday 16 February 2005, and armed with a Potomac Field Intensity Meter, shielded loop antenna and a mobile rig the two hams set out West to track the signals.

At about 2.30pm local time the two Hams arrived at the Laguna Indian Reservation and approached a compound containing buildings, towers and antennas and were able to confirm that they had found the source of the transmissions, The MATIC Center.

Part of Laguna Industries Inc., a Native American business, The MATIC Center was a military contract facility developing mobile communications battlefield systems for the US Army. MATIC stands for Mobility Assessment Test & Integration.

The Hams approach had not gone unnoticed, and as they took photographs of the buildings and antennas a man approached them yelling and ordering them to stop taking pictures. They beat a hasty retreat and headed home

The signal that had persisted for so long ceased sending its bizarre message three hours later and has not returned.

So was the whiole thing a few tech guys having some fun with a transmitter, or were these strange transmissions a test of some goverment communications system in development? Either way, using an Amateur Band frequency resulted in some attention and publicity that I am sure they did not appreciate.

Although Laguna Industries still existed when this article was written in 2011, all references to The MATIC Center had disappeared from their website, & when checked at the end of 2014 even the website itself had gone.

Update Jan 2015