dvb-c

[chusin]

Hello
I have a problem with the dvb-c tuning
I make a tuning with qam 64 symbol 6875 and I receive 100 channels then I do a tuning with qam 256 and symbol 6592 and I receive 80 channels but the receiver changes the first 100 channels and it puts qam 256 and symbol 6952 and they do not see
greeting