12 June 2010

50 MHz indicator for radio conditions

The TV transmitter in St. Petersburg in Russia, channel R1 49.750 MHz video carrier can be used as a radio  conditions indicator for meteor scatter, aurora and sporadic E. In this recording on June 12, 04:48 UTC you can hear the video carrier reflected by meteor ionized trails, one longer burst peaking S7 on the receiver display and one shorter peaking S6. There are also several other not so loud reflections. My receiving site was near Stockholm in Sweden, J099bd and the antenna was a quarter wave vertical antenna almost indoors. The distance to St. Petersburg is 700 km. Of course this indicator can also be used as an indicator for the 144 and 432 MHz bands. The analogue terrestrial TV transmissions in St. Petersburg will be changed to digital, started in 2010 so this indicator cannot then be used. Listening on a digital terrestrial TV transmission sounds like noise and is therefore of no use as an indicator. A digital TV transmitter´s output power is also much lower than an analogue one.