|
On the occasion of watching the LF band on
the Twente WebSDR, I noticed an unusual Luxembourg effect on the HGA
carrier 135.43 kHz. In addition to the "normal" ICM mumbling which is
muffled and symmetrical on both sidebands, the lower sideband carries a
relatively strong and wideband modulation. A quick listening scan of strong BC
stations shows that the modulation coincides with 639 kHz from Prag, which
is radiating 750 kW from a pair of 355 m high antennas. The geographic
constellation (Budapest - Prag - Holland) looks plausible for ionospheric
heating, but I have no explanation whatsoever for that one-sided spectrum!
Best 73,
Markus (DF6NM)
|
