Pixelation via Tablo - fine direct to TV

Equipment - antenna, preamplifier installed inside attic:

Antennacraft HBU33 antenna
ChannelMaster Outdoor Balun CM94444
ChannelMaster Amplify CM-7777HD Preamplifier
Tablo 4-tuner (Original version; purchased Nov 2015)
I am 10.5 miles from transmitter (as the crow flies). Its about 400ft higher elevation than me.
I had a local antenna company position antenna with a meter to point toward transmitter location.

Channel WKYC in Cleveland is pixelated - happens every minute or more. I can watch the channel fine when antenna coax connected directly to my Panasonic TC-P50G10 TV. Its annoying because this is local NBC affiliate I watch a few programs on there.

This channel recently moved in August due to some FCC re-assignment. I’m not having issues with any other channels on Tablo, mostly curious why its fine when I bypass the Tablo.

I tried watching live TV on Tablo with USB HDD disconnected as a troubleshooting step - still pixelated.

My Panasonic TC-P50G10 TV has a signal strength meter - it reports a consistent 86% signal strength. The tablo reports five green dots.

Any ideas? Thanks!

With the repack, obviously you’ve recently done a rescan, and clicked [add to guide].
Not that it really helps, you not alone, here’s someone with an original style tablo… been working for several years - now suddenly has issues with a channel

This may be a little late. I have a somewhat similar setup, but I’m much, much further from my transmitters (~30 miles). I also have a Channelmaster Pre-amp, and a Channelmaster 4-way distribution amp. I ran 4 TVs fine with that setup. When I got the Tablo, it would find all my channels, but all were pixelating (all showed 5 dots). I turned down the amp (I have the one with two power settings). It didn’t help much.

As a desperation move (and to make sure I had tried everything I could think of), I just wired the Tablo straight to the antenna with now pre-amp or dist. amp. Viola! It worked! Apparently I was overdriving the receiver in the Tablo (Dual Lite). I’m assuming the Tablo has built-in amps since it has multiple tuners.

I would suggest going straight from the antenna to the Tablo (no pre-amp), especially since you are relatively close to your tower.


Glad you were able to find the right solution for your needs!

I was just about to recommend removal of that preamp.

With high signal levels the Tablo’s tuner gets overloaded and distorts the RF signal.

Commercially available television sets do not overload at the same levels. I believe that happens because the television sets have much better automatic gain control stages, and so the high signal level is not amplified as much as the weaker stations.

This post explains that for the Tablo a signal higher than -50dbm is “too strong”. On the dbm scale -40 is stronger than -50.

But ATSC recommended high definition television receivers be designed to receive the signal at levels from -83dbm to -5 dbm. (-5dbm being the strongest.)

So, with the pre-amp TV signal strength meter would report 100% for channel WKYC but with pixelation.

I removed pre-amp - all other channels remained fine, but now WKYC still pixelated heavily but signal strength was reported as 40% - lowest of all of my channels. So with/without pre-amp this channel would not come in! WVIZ according to station engineer is on same tower as WKYC - WVIZ (which is lower power) comes in perfectly, WKYC does not!

Winegard’s antenna finder app said my antenna was pointed directly at the WKYC/WVIZ tower.

Just trying things I moved the antenna about 10 degrees to the west and mysteriously that minor tweak to antenna positioning plus removal of the pre-amp - everything is coming in clearly now! That little turn more than doubled signal strength on the TV’s signal strength meter.

Is it possible WKYC was coming in so strongly I had to turn antenna away from the tower a bit? Only thing I can think of.

Thanks for the help!