Radio spectral observations are carried out under computer control at the aerial site in Tremsdorf 15 km to the south-east of Potsdam. There is a set of 4 sweep spectrographs (10 sweeps per second in the ranges 40-90 MHz; 100-170 MHz; 200-400 MHz and 400-800 MHz). The spectral subranges are recorded by four distinct aerials: a pair of crossed double-log. Yagis, a 10.5 m paraboloid and two 7.5 m paraboloids. The parabolic aerials are paralactically mounted.

Spectral data have been available since May 1990, as digital data since September 1993. Beginning with autumn 1996, the sweep spectrometers run daily as long as possible (summer about 4 - 19 UT; winter about 8 - 14 UT). For special observing campaigns two multichannel spectrometers can be used additionally: the decimeter spectrograph (MCS, 693 - 740 MHz, time resolution 10 ms, bandwidth 1 MHz) and the meter wave multichannel polarimeter (chirp transform spectrograph, CTS; 316 - 337 MHz, bandwidth 135 kHz, 10 ms time resolution if only measuring Stokes I, 20 ms time resolution if measuring Stokes I and V). The CTS can also be positioned around a central frequency of 236 MHz.