DK0SF has been the Clubstation of Hamradio of Mercedes Stuttgart. As most of  the radio amateurs leaved the company to get retired or got to other plants, the club has been closed some years ago.

The callsign is still qrv, I am using that sometimes.

In 2005 DK0SF won 7th place  in the German Club microwave championship. The keyplayer were Peter DH2SAV, Harald DL9GBH and Slawek DL6SH together with DL4SBK, DL3SFB, DB2DV, DL8SAD, DL1SH, DF8XQ  and others.

I have been qrv during my Hamradio career from lot of other clubs:

DL0MI, Club Minden N12. I got my first licence in 1975 there.
DK0HF, Club Herford N08. From 1976 on wild time, contests with punch cards, outdoor power generators, lot of rain, bright-annealed tubes and tvice won German Club Championship.
OK2KJI, Club Jihlava in Tchech Republic. I was proud to do my first qso's in Chech language there in the 1980. My uncle Jindra OK2UHK was there chairman for log time.
DL0LB, Club Ludwigsburg P06. This was my first club in south Germany. In the meantime to far away from my new home. 
DF0MS, previously club call of Mercedes Stuttgart.
DL0ML, Club Waiblingen P37. I like to be member there and it is good to reach it when driving home from qrl.
OK1KKD, Club Kladno in Tchech Republic, on microwave. Dekuji Peter OK1FAQ / OK7FA!