Hej, we are THR! #
We’re a community of KTH students and alumni who share a passion for all tech things and, of course, radio waves. While our roots are in amateur radio, our activities span a wide range of interests, including electronics, computing, and other technical projects driven by our members.
Whether you’re a seasoned radio operator or just curious about building your first circuit, you’ll find a home with us. We are located up in the clock tower in the KTH campus, difficult to miss!
The club has the radioamateur callsign SKØBU, and it’s active on HF, VHF, and UHF. Sounds interesting? Read more.
We also have a well-equiped electronic lab for all of your projects, whether radio waves are involved or not, with a fairly large stock of components. All around our club you will also see many books and magazines: you will for sure find something to read!
We are also on Instagram!
Next events and Open Houses #
We usually hold Open Houses every first Tuesday of school months, and we’d love to have you as a guest!
Feel free to drop by at any of the dates below, or reach out for any question!
- 17:15: Open House
- 17:15: OpenHouse (theme: build a FM receiver)
- 19:00: Autumn general meeting
- 17:15: Open House
- 17:15: Lucia Fika
Our history #
Our club was founded in 1955 by some students of KTH, with the main goal of experimenting the world of radio communications, and to explore all the surrounding fields.
The club was once located at Nymble, the THS building, and moved to the current location on the top floor of the Clock Tower in 1965.
From 1970 the dome of the tower is adorned by our antennas, that have become a recognizable feature of the building.
The tower #
The clock tower, originally called Observatory Tower (Observatorietornet), was originally intended for the school of civil engineering for geodetic and astronomical measurements, is part of the original set of buildings erected in 1914 for KTH.
The copper dome, which could then be rotated and opened, sits at an height of about 74 meters, and it’s now visitable from our club premises.
Courious about the building history? Read more on the KTH page. And, of course, come and see it!
Radio waves before THR #
Before the club moved into the tower, our location has strategically been used for early television transmissions. With an antenna poking out from the dome, the first experimental Swedish TV transmission was done in 1954 from the tower, with experiments continued until the Nacka towers (Nackasändaren) were completed in 1956.
Parts of the original TV transmitter remained in the tower until the 1970s, and some pieces are now on display at Tekniska Museet, the National Museum of Science and Technology. The original TV antenna mast could be lowered through the top four floors of the tower. This mast was eventually replaced, but traces of its original mounts and hoisting mechanism are still visible on the upper floors today.
KTH was also active at the beginning of the century with experimental long wave transmissions. As reported in Svenska Dagbladet, April 30 1923:
For a few years now, the Institute of Technology’s electrotechnical laboratory has had a 2-kilowatt Telefunken spark transmitter. The facility, which in the trials so far has only been used together with an ‘artificial’ antenna, is now completed with an aerial antenna, supported by two masts placed on the roof of the laboratory.
Read Eric SM6JSM’s article from QTC 04/2023 here (in Swedish).
