LF: Grabber on fire

[MarkusVester@aol.com]

Dear LF group,

during many nights my grabber screen resembles a bushfire, with all those red Luxemburg stripes above the Budapest signal, like flames around an orange SXV...

One of the most prominent ionospheric heaters is Solt, Hungary with two megawatts on 540 kHz. Almost every night around 23:13, it transmits a 1000 Hz audio test tone for a couple of minutes, very useful to quantify the cross modulation sidebands imposed on several stations. Due to the quadratic nature of the heating, there is also a pair of second harmonics, 2 kHz from the affected carriers.

Sat 06-11-25, 23:10:45z to 23:13:45z

f/kHz dBuV/m  origin

138.83 ~71  DCF39 carrier (nighttime)     

138.04   3  \ Turkish FSK 
137.96   3  / 139kHz - 1kHz
137.83  15  DCF39 - 1kHz
137.43  17  Budapest + 2kHz
136.83  -6  DCF39 - 2kHz
136.43  39  Budapest + 1kHz

135.43 ~76  Budapest carrier (night)

The grabber snapshot is at http://members.aol.com/df6nm2/ICM_061125_2315z.gif (77kB). 

Though the ICM is normally much stronger at night, it is now often visible during daylight hours as well.

73 de Markus,
DF6NM in JN59NK