What is the intended behavior of "duplicate" virtual channels?
 

I live in a fringe-reception area with a very lively broadcast market (San Francisco), and I'm puzzling over what should happen when there is "station ambiguity." Here's the background:

• A powerful local station (KGO, virtual 7) broadcasts on real channel 12...I get that all the time
• But it also broadcasts the same virtual channel on real channel 35
• Under some weather patterns, I can get some signal from the real-channel 35 version

So...let's say I get enough signal on 35 on a particular day: does the TV know to ignore it (because it already has the same call sign stored on the same virtual channel), or is it conceivable that the channel 35 signal could displace the channel 12 signal in the lineup?

The answer may be "it depends on the tuner..."--but does anyone know what the specified behavior should be?

This might not be the answer you're looking for. But I do know that some stations will transmit on another RF frequency as a backup or to fill in bad reception areas. I believe the VHF stations do that more than UHF stations. A local apartment building owner uses a MATV system.

I look at the antenna on his roof I noticed it didn't have VHF. I asked him how he gets RF12, one of our local CBS stations. He says he gets it off of another UHF sub Channel.

So, they might do it for apartment owners or people who simply don't have a VHF antenna. Now that I've said that, hopefully you'll get the real answer!

I had a similar case a few years back. Memory on it is a little bit fuzzy, but I believe my Sony's channel list under this scenario included duplicates of the virtual channels. So when you flipped through the channels, the first 28.1 that you came to was on one RF signal and then the next channel up (also a 28.1) was from a different RF signal.

I got a similar behavior last weekend when I had to do a re-scan due to the FCC repack. I had duplicate virtual channels in the channel list, but one of them was reading "no signal" because the station is no longer broadcasting on the RF signal that that virtual channel is associated with.

Does that make sense?

Yes I have seen the virtual Channel show up in duplicate myself. I'll have 1 in Milwaukee and one in Chicago but they're different RF signals.