Vivitek RP56HD21-A - Manual (Page 28)

Connecting Off-air TV or Cable TV
To connect off-air TV or cable TV using coaxial (RF) audio and
video :
1 Connect the coaxial (RF) connector from your antenna or cable box to the
TV/CABLE IN connector on the back of your RPTV.
2 Select TV using the INPUT button on the front of your RPTV.
Warning If an outdoor antenna or cable system is connected to your
RPTV, make sure that the antenna or cable system is correctly
grounded. For more information, see “Television antenna
connectors protection (for systems fitted with TV/cable TV tuner
cards)” on page 52.