NEC NHD-3000PVR - Manual (Page 13)

Connecting Antenna
11
Antenna Input 05
Installation
Connect the antenna or RF cable wire directly to ANTENNA1 IN and connect ANTENNA1 Loop
Out to ANTENNA2 Input by using RF loop cable.
NOTE
The STB(Set Top Box) should be unplugged before connecting antenna. (Power OFF mode)
The RF OUT from the tuner will only work when the unit turns on. It will not give RF OUT during
STANDBY mode.
THE RF LOOP CABLE MUST BE CONNECTED, OTHERWISE THE UNIT WILL NOT
BE ABLE TO TUNE.