Why is ATSC3.0 so unstable?

[tjp]

I have a HDHomerun Flex 4. There was a football game today that was being broadcast on station (KRON) that has both a ATSC1.0 and ATSC3.0 (undecrypted) channel. The ATSC3.0 channel would periodically (about every 90 seconds) breakup while the ATSC1.0 channel was always rock solid.
---------------ATSC1.0----------ATSC3.0
Sig Strength--98%--------91%
Sig Qual-----100%--------100%
Sym Qual ---100%--------100%

Why is the ATSC3.0 tuner performing so badly? Surely these reception values are high enough for a stable picture?

[geriakt]

In my opinion, many of us ATSC 3.0 enthusiasts claim to have this problem or assume is is the turner device. In most of my findings is has to do with the player device such as an Android STB with incorrect sound codec settings or with your TV sound settings on PMC and not pass through to your 5.1 AVR or sound bar.
Other times is is the station broadcast because they are just upscaling or converting the ATSC 1.0 /AC3 780p or 1080i to ATSC 3.0 HEVC/AC4. 1080p/AC4 and your player is swapping through different codecs to play it.
My ATSC 3.0 non encrypted using HDHR Flex 4k played through my Android 11 STB with certified AC4 codec having the android HDHR player set to passthrough, my TV sound set to passthrough and my AVR playing the bitstream does not ever shutter, blip out, pop, or not play HEVC/AC4 broadcasts. If I ever do see a broadcast issue it is mainly with live sports on the OTA ATSC 3.0 during a commercial change over.

My advice is play around and adjust your Bitstream/PMC sound settings on your STB and TV.

[ckwsp101_tv]

In the Bay Area ATSC 3.0 stations come from light house transmitter on Sutro Tower,.
KRON station feed split to ATSC 1.0 and ATSC 3.0 systems on Sutro.
Could be something in ATSC 3.0 system at Sutro.

https://explore.sutrotower.com/

[Cabal]

In addition to the reasons already mentioned, the ATSC 3.0 lighthouses frequently broadcast at much lower power than the main 1.0 stations, even when they are in an optimal location. The exact numbers will vary by market.

[jasonl]

KRON hosts the ATSC 3.0 broadcast on their VHF channel 7 broadcast. Their 1.0 channel is carried on KTVU's UHF channel 31 broadcast (and in the South Bay, the UHF channel 26 repeater on Monument Peak). VHF is far more susceptible to interference from other electrical and electronic devices than UHF is, and the lower the channel, the worst it gets. A lot of seemingly innocuous things like LED and CFL light bulbs, solar panel inverters, and anything that turns electricity into motion (fans, motors, pumps, compressors) can potentially cause issues. Do you also see issues on KGO and KNTV's 1.0 broadcasts? Those are also on VHF.