Biedenkopf transmitter, Radio transmission facility on Sackpfeife mountain, Biedenkopf, Germany

The Biedenkopf transmitter is a steel lattice mast standing 210 meters (690 ft) tall on a hilltop near the town of Biedenkopf in Hesse, Germany. The mast is surrounded by technical support buildings that house the broadcasting equipment.

The Biedenkopf transmitter was first built in 1953 as a steel tube pylon on the Sackpfeife, a 673 m mountain on the Hesse–North Rhine-Westphalia border. In 1987 it was replaced by the present 210 m guyed steel lattice mast, which stands on a sphere and has a 1.8 m × 1.8 m cross-section. Because of its proximity to North Rhine-Westphalia, the WDR also uses the site, under the name Sender Wittgenstein.

The mast broadcasts radio programs that reach much of Hesse and nearby regions, making it a quiet but constant presence in daily life for people living in the area. Many local listeners have tuned into the same stations carried by this transmitter for decades.

The mast is visible from a distance and can be seen from the hiking trails that run through the hills around Biedenkopf. The facility itself is not open to the public, but the surrounding area is accessible on foot.

In 2016, the site switched to digital broadcasting as part of a coordinated national rollout of DAB+, the German digital radio standard. This means more programs can now be carried on a single frequency than was possible under the older analog system.