OFFAIR, IRC, HRC, etc. on 622

[SmokeFan14]

I did a search on this site and found a few responses/answers, but not being very tech-fluent, could someone please explain in layman's terms what this is referring to? I have an OTA running into my 622 and currently the (622) receiver is set to "offair". I'm just curious what it means and if I'm right in having it set to "offair". If I'm not mistaken that's the default setting..? Everything is working fine. That's why I haven't messed with it; "If it ain't broke don't fix it". Thanks. Joey

 

[vegassatellite]

The OTA tuner is meant for ATSC signals. That's the format used for off-air broadcasts. Most cable systems use QAM signals for their digital channels. However, some cable systems just re-transmit the ATSC signals that they receive themselves. If your cable system is one of them, then you can switch to whatever type your cable system runs off of. For example, a local UHF station might be carried at a different frequency in the cable system in the STD, HRC, or IRC frequency plan. HRC and IRC just use offset frequencies from the STD cable plan as they can help reduce composite triple beat patterns (CTBs) in the picture.

Also, just to make it clear, most cable systems don't use ATSC signals. Some do and they often do it by just re-transmitting the OTA signals on their lineup.

 

[Jim5506]

The tuner will actually receive cable channels in the HRC and IRC and cable modes, but they must be ATSC, not QAM, and I don't know of any cable system that still uses ATSC.

Some people have accidentally put their tuner in one of the cable modes and lost all their OTA channels above 13, but the VHF still works because the channels and frequencies are the same for OTA and cable in that range.

It is a curiosity but not very useful.