Radio spectral observations are carried out near the village Tremsdorf 15 km south-east of Potsdam (52.284° N, 13.134° E, map). A set of four sweep spectrographs (10 sweeps per second) is fed by a system of four different aerials in the ranges 40 MHz - 100 MHz, 100 MHz -170 MHz, 200 MHz - 400 MHz, and 400 MHz - 800 MHz. We use a pair of crossed double-logarithmic Yagis, a 10.5 m paraboloid and two 7.5 m paraboloids. The parabolic aerials are parallactically mounted. This way we see the sun at all frequencies as a star - no image resolution is obtained. The signal is a spatial integral over the radio noise of the whole sun. Strongest man-made interference is between 85 MHz and 108 MHz (local UHF radio), 170 MHz - 200 MHz (local UHF TV) and between 550 MHz and 700 MHz (local VHF TV).
Observing time is as long as possible in the year (summer about 4 - 19 UT; winter about 8 - 14 UT).
For special observing campaigns two multichannel spectrometers can additionally be used : the decimeter spectrograph (multichannel spectrograph, 693 MHz - 740 MHz, time resolution 10 ms, bandwidth 1 MHz) and the meter wave multichannel polarimeter (chirp transform spectrograph, 316 MHz - 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 chirp spectrograph can also be positioned around a central frequency of 236 MHz.
Important (regularly working and solar dedicated) radio imaging instruments are the French Multifrequency Radio Heliograph (images at five frequencies in the range 150 MHz - 450 MHz) and the Japanese Microwave Heliograph in Nobeyama (images at 17 GHz and 34 GHz).