690 kHz Spectrum Monitoring 24h

carried out by Günter Lorenz (mailto:glorenz@lorenzsoft.de) between 03.10.2004 and 09.10.2004. All times UTC.

Equipment: EKD500, Grahn magnetic loop, Spectrum Lab software

Location: Freising, Germany

I started observing 690 kHz to find out more about the Libyan tx. It carries the same programme as 1449, but seems to operate irregularely. It is not even known if it is a regular transmission or a spurious radiation. It usually is weak, creates a heterodyne on 693 and has a weak audio.

The following is a day-by-day watch at the late afternoon and night spectrums:

http://www.myradiobase.de/mediumwave/capt690_04.jpg 03.10.2004

LBY on .999 s.on just after 18:00, carrier continues all night.

What might be TA on .998 is seen as early as 00:00, another possible TA is seen with its sunrise lift at around 05:20 on .001

http://www.myradiobase.de/mediumwave/capt690_10.jpg 04.10.2004

LBY on .0005 fade in at 16:00,very strong peaks (red=Audio). s.off at 22:40

Note the faint carrier on .000, from 15:52, just left of the strong LBY, slowly fading out.

The first TAs fading in 23:30 (.998), and a short sunrise lift at 05:30.

http://www.myradiobase.de/mediumwave/capt690_16.jpg 05.10.2004

LBY on .999 16:10 fading in, getting very strong (red=Audio), s.off 22:30

TAs fading in 23:05, up to 4 distinguished carriers (http://www.myradiobase.de/mediumwave/capt690_18.jpg)

http://www.myradiobase.de/mediumwave/capt690_22.jpg 06.10.2004

LBY fade in 16:30, quite strong, s.off 16:55 ! on .9995

A faint trace from 16:00, s.off 20:20 on .000

TAs from 00:07, 3 distinguished carriers http://www.myradiobase.de/mediumwave/capt690_24.jpg

http://www.myradiobase.de/mediumwave/capt690_28.jpg 07.10.2004

Now, this gets interesting. I believe that LBY is .9995 s.on 20:05 and s.off 20:31 (also in the past, I have noticed such short periods). But then who is fading in 15:40 and fading out 19:55 on .000 ? Also notice the faint trace on .998 from 16:00 to 17:40, peaking at 16:30

TAs fade in around 22:45, again 3 carriers. http://www.myradiobase.de/mediumwave/capt690_30.jpg

http://www.myradiobase.de/mediumwave/capt690_34.jpg 08.10.2004

No LBY at all. But on .990, unid fading in at 15:25. fading out after 19:10. And another one, from 16:10 to 19:20 on .000

TAs from 22:40

http://www.myradiobase.de/mediumwave/capt690_39.jpg 09.10.2004

unid s.on 15:52, s.off 18:00 on .000

No trace of LBY.

Typical trace

There is a typical trace which appears almost every day. I have grouped this information below.

Hope it is a mediumwave tx and not a spurious from my neighbours kitchen radio ;-)

03.10.2004 16:20-19:00 .014-.015v

04.10.2004 16:10-19:00 .015-.016v

05.10.2004 16:55-18:43 .015-.016v

06.10.2004 15:50-19:10 .015-.016v

07.10.2004 16:00-19:12 .015-.016v

08.10.2004 no such typical trace. But it maybe one of the other unids.

09.10.2004 15:45-19:01 .990-.991v

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