There is no magnet preceding the eastbound signal on track 2 (as viewed from the left eastbound) at MP 106,6. There is a Vorsignal1km before as there should be, but no 500hz magnet 250m before the Hauptsignal at 106,6.
Not sure about the exact location you are describing, but on the S-Bahn tracks are signals without a 500Hz and that is prototypical. Afaik this was done like that to speed up services, and while unusual it is prototypical.
