[Spooks] Update Unid 14 and 18 Mhz

[Martin Potter]

Tom Norris wrote:
 >
 > An update.
 >
 > ~18086, 18090.5, 14727 and 14730.5 approx were identified
 > as Bulgarian Diplo MSK signals. Just had not heard that signal
 > in the states before.
 >


Tom,

I think you will find that this signal is the Cuban bubble jammer 
("Havana Gurgle"), usually directed against Radio Marti.

On 18090.0 kHz (center freq) the tone bursts are 300 Hz apart, 
ranging from 1200 to 3300 hertz in each sideband.  It is the 
third harmonic of the jammers (almost always more than one 
transmitter) on 6030 kHz used by Radio Marti.  This third 
harmonic is a familiar "friend" of Amateurs using the 17 m band 
and is frequently reported as an intruder (which it certainly is).

I just listened to the one on 14730.0 kHz (center freq) and found 
tone bursts from 800 to 2200 hertz, indicating a probable second 
harmonic.  Sure enough, the fundamental is on 7365 kHz (though I 
don't know who the target is).

At the fundamental, the tone burst frequencies are separated by 
100 hertz and range from 400 to 1100 hertz.  From any one 
transmitter the tone burst period is around 88 milliseconds, 
although with more than one transmitter active it is difficult to 
see any consistent period.  Some "intruder watch" monitors have 
suggested that each sideband is identical, that is a tone is 
transmitted in both sidebands at the same time, although I have 
not been able to test this myself.

If memory serves me right, the signal was first reported on 18090 
during summer 1998 and by early 1999 was being reported 
regularly.  The Cuban government has ignored all requests to fix 
the harmonic radiation, creating great embarrassment for Cuban 
Amateur Radio operators.  The jamming transmitters were reported 
to have been built in China and it is possible that they are not 
easily modified.  We seem stuck with the problem for as long as 
the Castro government chooses to jam Radio Marti.

73,
... Martin    VE3OAT


http://www.storm.ca/~iarumsr2/