A MAG 275 box is - besides its DVB - nearly equal the MAG 254.
But you are right: ATSC is not DVB-T
Here a nice picture:
Dark Blue = DVB-T/T2
Green = ATSC
Source:
But the MAG 275 is also a Cable box with its antenna connector for Cable TV!Code:http://www.dtvstatus.net/
Manfred