Digital cable TV System
STD, HRC, and IRC are cable television formats. If your manual doesn’t explain it (always RTFM!), you are here for help in scanning (auto programming) channels for their HDTV.
STD HRC and IRC Reference
While the terms HRC and IRC are slowly phasing out, many TVs still allow the option of setting up your tuner to one of these 3 formats.
| STD | Standard |
| HRC | Harmonically Related Carriers |
| IRC | Incrementally Related Carriers |
Additionally you might have the option to select analog vs digital. You want digital if available, but it likely won’t matter as analog cable is going the way of the dinosaur and if you have a “digital cable box, ” all your programming is coming into the house digitally already (and then converted to analog by the box).
What’s the Difference
Older cable trunk lines suffer from signal degradation over and distance and require amplifiers to maintain signal strength. This amplification introduces noise into the cable signal. HRC and IRC are formats that the cable companies use in an attempt to clean up signals and improve audio/video quality. They slightly alter the frequency in order to make interference less noticeable, but most people would be hard pressed to tell the difference.
Modern cable installations run fiber optic lines and do not require signal improvements. Today, most cable systems use STD.
Cable signals are sent through lines with a frequency, measured in MHz (megahertz) like cordless phones or computer CPUs. HRC and IRC try to eliminate interference, which comes in the form of “beat noise”- a term describing “concentrations of energy in the frequency domain.” Ya, that’s not too technical! We don’t care about all that. We just need to know which one to use…
Which do I Choose?
This is an from Brighthouse Networks and also our Solid Recommendation:
Always select STD (standard) if your TV offers this setting. Choosing the others could result in reception problems or missing channels.
If you have cable TV and live in a major city, or if you have satellite television like DISH Network or DirecTV, then you want to always select STD standard.
If you live in a rural community that is running an older cable system, then you might benefit from trying HRC or IRC. Results will vary as it is not an exact science, but you should take notes of the number of channels found and your opinion of quality between each. After comparing, choose which one you like.
