Did something change again? Last time this happened we had to get a bigger antenna to pull in even the strongest channels.

Last night we noticed that channels with strong signal strength seemed to be weaker and those with normally weak signal strength just don't come in any longer. Every time I rescan for channels I get fewer channels.

Supposed to be a new broadcast standard coming. Will require new tuners or TV's. We only watch a couple channels. Can't force myself to watch what passes for the "news". Our TV time is down to a couple hours a day and that is Streaming. No point anymore.
broadcast signal strength may vary during the day/night

Check your antenna cable connections for possible looseness, corrosion, and/or water intrusion. Also check the ground. Another possibility, if an outdoor antenna, perhaps the wind has pushed it askew. There are websites that help you find the optimal alignment, I think TV Fool is one of these.

Some OTA stations have changed frequencies. Enter your zip code, or let the web page access your location to find what may have changed and general reception info. If they changed from VHF to UHF frequencies, the reception range would likely be reduced.

https://www.fcc.gov/media/engineering/dtvmaps

Also, they may reduce power at night to reduce interference with other stations on the same channel/frequency.

quote:

Originally posted by mark123:
Did something change again?

Yes, it did. Or, more accurately: It is in the process of changing. The move from the ATSC 1 digital broadcast standard to the ATSC 3 digital broadcast standard (aka: "NextGen TV").

Of course they "had" to make the new standard un-backward-compatible with the old standard. Why? Because.

Since the new standard is incompatible with the old standard, and the FCC mandates broadcasters have to simulcast in the old standard for a minimum of five years after the new standard becomes the standard, here's what stations are doing...

quote:

Originally posted by mark123:
Last night we noticed that channels with strong signal strength seemed to be weaker and those with normally weak signal strength just don't come in any longer.

That's because what those stations are doing is moving their ATSC 1 broadcasts to sub-channels on other broadcasters' transmitters, then changing what they transmit to ATSC 3.

E.g.:

Before changes (all ATSC 1):

Real Channel   Virtual Channel

    24               7.1
                     7.2
                     7.3

    32              50.1
                    50.2

After changes:

Real Channel   Virtual Channel

    24               7.1 ATSC 3
                     7.2 ATSC 3
                     7.3 ATSC 3

    32              50.1 ATSC 1
                    50.2 ATSC 1
                     7.1 ATSC 1
                     7.2 ATSC 1
                     7.3 ATSC 1

Because ATSC 3 is entirely incompatible with ATSC 1, and vice-versa, channel N.N can appear as the same number on both.

If real channel 32 is weaker, further away, or has a radiation pattern that does not favor you, you may experience degradation on virtual channels 7.x that you didn't before.

quote:

Originally posted by mark123:
Every time I rescan for channels I get fewer channels.

Not surprising.

This, I predict, is only the beginning of all the "wonderfulness" that ATSC 3.0 will bring us. Enjoy!

ETA: I just realized you didn't write "a station" or "some stations," but implied all your strong stations got weaker and all your weak stations disappeared. If this is the case it probably is not the move to ATSC 3, but something wrong with your TV, the antenna feedline, or the antenna.

quote:

Originally posted by ensigmatic:
... ETA: I just realized you didn't write "a station" or "some stations," but implied all your strong stations got weaker and all your weak stations disappeared. If this is the case it probably is not the move to ATSC 3, but something wrong with your TV, the antenna feedline, or the antenna.

I've checked the connections. I don't know. I'll give it another once over.


Thanks for the info, friends.

The wife's favorite channel came back today. It must have been weather related but we've not lost any channels like this since I climbed on the roof to install this antenna. Just a strange incident.

I was thinking you were lucky.

In my experience, it changes constantly, Seasonally for sure, but sometimes day to day. (weather related I assume)

quote:

Originally posted by cas:
In my experience, it changes constantly, Seasonally for sure, but sometimes day to day. (weather related I assume)

Ever since the last re-pack, concluded 'round about last July, we no longer have weather- or aircraft-related issues.

This video does a good job explaining:

https://youtu.be/M-J5IlRyzeQ