Local radio station Wertingen – The museum radio
The local radio station Wertingen is part of the Radio- und Telefonmuseum Wertingen and was created to demonstrate visitors old devices without VHF reception. The local radio station can be operated with low power at any time, the event radio, however, broadcasts with higher power to certain events.
Broadcasting during regular opening hours.
The medium wave transmitter Wertingen was first approved by the Bayerische Landeszentrale für neue Medien (BLM). The transmitter can be operated at any time. However, the range is limited to approx. 100 meters.
Transmission frequency is 801kHz. This was assigned to the operators by the Bundesnetzagentur (BNetzA).
This frequency was previously used by Bayrischer Rundfunk. Since end of 2015, BR unfortunately no longer transmits on medium wave.
Transmission power is about 2 to 5 watts. There are two transmitters to choose from: A compact transistor transmitter built by Helmut Rau, DC4VK. On the other hand, a tube transmitter can also be used. The tube transmitter consists of three tubes which were previously used in a television set. The tube transmitter was built by Bernd Schmid, DL2MFP.
For the antenna a symmetrical dipole is used which is suspended in the museum building under the attic. The dipole is 2 x 20m long and is fed by a ladder line. At the transmitter output there is a symmetrical Collins Filter, which takes over the symmetrization and the matching to the antenna.
The radio station is always in operation during regular opening hours of the Radio Museum. This is every 3rd Sunday of the month from 2 pm to 5 pm.
Higher transmitter range at events.
Since 2018, the station has also been used as an event radio station on certain days. The BLM has approved a range of about 3 km, which covers the entire city of Wertingen.
For the event radio a tube transmitter and a power amplifier from Sommerkamp, type FL 2500, are used for the longer range. The tube transmitter consists of three tubes used in former TV sets. It was built by Bernd Schmid, DL2MFP.
With the transmitter and the amplifier approx. 70 watts of carrier power are achieved. The amplifier did not have to be modified. Only an output circuit specially tuned to 801 kHz is connected. For the antenna a 10m high aluminium mast is used, which is tuned to the transmission frequency by means of an extension coil.
For the event radio there are the following broadcasting dates in 2019:
Nov. 15th. to the “Wertinger Night”, from 5 pm to 11pm.
Dec. 8th. on the Wertinger castle Christmas, from 2pm to 6pm the transmission is repeated on Dec 15th. at the same time.
The programs are pre-produced by Bernd Schmid and broadcast in the Radio Museum as MP3s. Bernd Schmid has set up a small studio at home for this purpose. It consists of a mixing desk, two record player and a microphone. Original records from the 20s to the early 1970s are played. Shellac and vinyl records are used.
The history of the transmitter
In the following Bernd Schmid, DL2MFP reports about the history of the transmitter.
The idea of an own station for our radio and telephone museum grew in us when it was decided to shut down the medium wave stations. Many of our radios can only receive medium and long waves. Now it was a matter of demonstrating our visitors some of the devices in sound and operation. Bernd Schmid, our “radio operator on duty”, said that he wanted to build a small transmitter and would care about of getting a “broadcasting licence”, because without this no transmitter could go “on air”.
In May 2015 Bernd Schmid asked the Bundesnetzagentur how to reach the goal. The answer was: “You first need a broadcasting licence”.
June 2015: A request was made to the city of Wertingen as the owner of the radio and telephone museum whether we would like to try it. Mayor Lehmeier agreed. If the costs remain within limits and the administration is not burdened with them, we could give it a try.
July 2015: Application of the “Broadcasting Licence” at Bayerische Landeszentrale für neue Medien (BLM) in Munich
September 2015: The city of Wertingen received a “broadcasting licence”.
October 2015: An application for “allocation of a medium wave frequency” was submitted to the Federal Network Agency.
November 2015: The Bundesnetzagentur had decided that we should get the 801 kHz frequency of Bayerischer Rundfunk as soon BR returned its license.
January 2016: Allocation of the medium wave frequency 801 kHz to the city of Wertingen. A person had to be appointed, who is responsible for the station as broadcasting manager and who sets up the station according to broadcasting law conditions: that is Bernd Schmid from Bocksberg.
January 2016: Bernd Schmid installed a small transmitter and the antenna for test operation, spoke news and messages on a mobile phone, which he then connected to his small transmitter – it worked great.
January 2017 at 2pm the local radio station Wertingen was broadcasting for the first time on World Radio Day 2016 on the medium wave frequency 801 kHz.