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As Manu explained me it's not possible to set manually rolloff/FEC for stb0899. that's why I'm wondering - what for need the new roll off (parameter O) parameter in channels.conf ? Only for reading the current state of roll off in demod ? (0,35% is default for dvb-s/s2 BPSK, QPSK, 8PSK) Is work really ?

It's a transponder parameter that is broadcast in the NIT and can be set in the DVB-API. VDR simply "hands it over" and doesn't care if a particular device uses it or not.

thanks for your answer. It's clear for me now

Or did I misunderstand your question?

you understood me correctly :)

Goga