AM radio station with high frequency co ... / 2012-10-08

AM radio station with high frequency components

Playing with the Wide-band websdr at the University of Twente ETGD radio amateur club I browsed the AM medium wave broadcast band. Just above the defined mediumwave broadcast band was a (pirate) station at 1620 kHz, clearly using equipment not built for broadcast-quality AM transmission within the normal frequency grid. With the waterfall display offered by the websdr interface it's easy to see the high frequency components, way more than a normal AM radio station (4.5 kHz above and below the carrier frequency in the ITU region 1 mediumwave frequency grid). The signal seems to have a components of more than 30 kHz offset from the center frequency. Compare the station at 1557 kHz limited to 1552.5 - 1561.5 kHz.