I do not have cable TV. Over a year without. Last night, I went to watch Pawn Stars, channel 3, 11:30 PM to 12 AM then 12 AM to 12:30 AM. No channel available, no signal. Now mind you, I watch different shows on channel 3 during daylight hours. Fast forward to 11 PM tonight. Same issue, no channel 3.
Today, I have been watching shows on channel 3 including shows at 4:30 AM with no problem whatsoever. Nothing yet. I will try to determine when it comes back on.
Has anyone else been dealing with this crap?

4:30 AM it finally decided to come back on. All of the other OTA channels have been working fine.

I noticed the same thing.
When channel 3 came back 8, 10 & 12 were gone for a while.
I figured my antenna was dying.

The part that makes me wonder is this happened 2 days in a row. Same time, same place. I have had similar experiences with different channels. The majority of transmitter antenna are located close together on South Mountain. My antenna is rotated towards that area. I have a signal strength meter that tells me when the antenna is aimed at the tower. I have not had to move the antenna since I originally installed it. I have marks on the azimuth I can glance at to make sure the wind hasn't moved it.
I plan to call the channel office today to see if they are aware of any outages. Or I could wait until this evening and see if it happens again. But being the weekend, I wouldn't be able to get any info until Monday.

I have suddenly had problems with 10.3 and 10.4, but not 10.1 or 10.2 .... weird

Sometimes they power the towers down when they have to go up on South Mountain or Shaw Butte to do work up there. I have to re-scan for new channels every few months after they drop off.

Does anyone get the really high numbered KPNX / KSAZ/KAET (cox #81-#84) with their antenna? It would be nice to be able to pick some of those up on multiple TVs through the house.

I have three TVs and only 1 can get channel 3 and then still inconsistently.  What I didn't realize, despite the same antenna, different TVs will have different ability to pickup channels.

I live sort of close to the towers, I think I have foothills block my LOS and we are kinda low which means I get less reception than you would normally think.  And different times of year most notably after big temp swings, I have to rotate my antenna just to get the four major networks consistently.  Usually ABC is the most sensitive.

What antennae are you all using?  I want to buy one.

I have one of the older version of these behind my TVs and it works decently in the north valley.

Well, I have the problem repeating. Outage on 11-2, and 11-3, starting 11 pm has not happened since then. Now, here it is 11-10, and no channel 3. I had TV tuned to 3.1, Channel 3 news. Next on the line-up is Pawn Stars. I was in the bathroom, and could hear the TV. I heard the show come on, and the guy asked the first customer what he had. Then silence. Black screen, message saying weak or no signal, check antenna, etc. I check other channels and all are normal. Only channel 3 (3.1, 3.2, and 3.3) is out. Again. I will keep an eye out to see when it comes back on. This **** is pissing me off.

I am editing this to add that Channel 3 came back on at 4:30 am. It appears there may be a pattern developing.

I lost my channel 61, out here by Kingman, and it was because the signal strength was just a little to low to come in. I have a signal booster but had it turned down. Once I turned it all the way up the channel came back. I am running through a TiVo box and it splits the signal 4 ways, since it can record 4 shows at once. That splitting was just enough that the signal for 61 was not good enough. You might try a signal booster box, they are not that expensive.

I have the Winegard Sensar IV antenna and the Winegard Sensar Pro signal strength meter. The system has been pretty much trouble free for the last year or so. I have re-scanned but that was unnecessary. The channel 3 outage seems to be temporary for a few hours each time. I need to see if I can pick the channel with my digital scanner and note the channel frequency.

I have no issues with channel 61 or the sub-channels.