Pixelation, signal shows five green dots

I live in Toronto about 3 miles west from the CN Tower which transmits most of the stations including Global. When I scan the channels on the Tablo Global shows a consistent 5 green dots implying the signal is not problematic. My LG TV has a signal strength meter built in that shows between 55- 65% strength with 100% quality. Global shows pixelation and break up. It might be more than Global but that is what we watch the most. I have not seen it this bad on any other channel. The reason I have been given by Tablo support is signal strength but if that is the case why does it work great most of the time and show 5 green dots. I moved the antenna closer towards the tower(as per TV Fools coordinates) and it helped a bit. Buffalo still comes in strong if it is a clear day but Global continues to give issues. It was very bad Sept 5th.I videoed some clips for your perusal. Is it possible my usb drive(WDPassport 2 tb) is the issue? Your feedback would be most appreciated. Thank you.

Do you have trees in front of the antenna? Swaying branches and leaves will cause pixelation.

Pixelization is almost always a reception issue. The HD is simply recording / playing back that which was presented to it. The 5-dots, shown by Tablo, shows the strength of the signal, but does not reveal anything regarding the integrity of the signal. In strong signal areas, like yours, it is possible that your signal is too strong, and the tuners inside of the Tablo are overwhelmed. Also, if you’re using an antenna mounted inside, the reflections off of animate objects (spouse, kids, even large pets) can be significant enough to cause a second signal to be received by the Tablo. Since this second signal is “time-shifted” by a very small amount of time, it confuses the digital error correction logic in the tuners. Pixelization occurs (among other causes) because the digital signal can not be decoded correctly. In very strong signal areas, I’ve seen improperly applied coaxial connectors also cause problems, as a “cat-whisker” (a single strand of the outer “ground” of the coax) touches the inner, solid conductor.

You may want to try the following: if you’re using an inside antenna, try multiple placement locations. Also, an adjustable attenuator may help, as it will reduce the reflection as well as the main signal. Reflections are very hard to completely eliminate, as nearby buildings and trees can also cause problems. Some tuners, like those in some TVs, do a better job of managing the issues of reflections.

An attic mount antenna can help the situation, but reflections can still be a problem as many attics have foil-backed insulation and some homes also have HVAC equipment in the attic. Attenuation will likely by more necessary, as the signal will appear stronger.

An outside antenna with a clear shot of the tower is best, although heavy attenuation will likely be required. In your situation, I would want to first use a very minimalist outside antenna, as I would want as little antenna gain as possible, and as wide reception angle as possible. This would allow me to aim the antenna “off-angle” to the tower, to possibly avoid other local reflections from objects in the local area.

I’m in a situation similar to yours – my signals are concentrated in one area (10 degree spread) from towers as tall as CN Tower. Power output is similar, too. I live about 6 miles away, in flat terrain. My antenna is in the attic, and I need to aim about 20 degrees away from the optimum angle to avoid blockage from tall trees and 2 story houses nearby. I have attenuated my signal by about 15 db. Still see occasional pixelization (a second here or there, about 3 times per week). This is likely caused by the wind rustling the leaves on our maples and is only a problem during warmer months.

Hope this info helps…

You say it’s only 3 miles away? What antenna do you have? Maybe you’re over driving the Tablo tuner, as in the signal is too strong cause you’re so close to the transmitter.

Thank you for the advice. I should’ve mentioned that my antenna is a directional antenna sorry I don’t know the brand name it is mounted on my balcony railing pointed at the tower angled up. My Tablo is a Tablo quired. The only issue I have is with global. The other stations coming off the tower work fine with the exception of Citytv which I cannot receive at all. I think I mentioned that the quality of the signal is 100% but the strength is 60 to 65.

And yes there are trees between me and the tower. That being said, why are CTV and CBC and TVO in strong? I pondered putting an amp between the antenna and the Tablo but given the distance to the transmitter I fear it would over drive the tuner.

Is your antenna pointing at the tower directly or are you trying to get both Toronto & Buffalo by pointing midway between them?

You can try attenuating the signal by putting in a cheap splitter since according to TVFool your signals are very strong.

If you ever need a preamp for just one channel, Jan Jenca makes preamps for single channels leaving the others unamplified. But for three miles, you shouldn’t need one.

BTW CITY-DT is to move from 44 to 30 due to the repack. Perhaps there is work being done on their transmitter. However CITY starts their repack May 2020.

I am aiming slightly south of the tower. I am am about to add coupler with omnidirectional for Toronto and the directional facing Buffalo. I think I got City Briefly once. I am baffled as to why only one signal out of all the ones from the tower would give me issues. Sadly it is our preferred news station. I have been watching CBC and CTV more and have yet to see any issue.

I have exactly the same issue! Same channel: Global TV is pixellating, but in a completely different location, I’m in Gatineau [Aylmer], Quebec. I’m pulling from 2 towers.

  1. The newer Ryan Tower at Camp Fortune is 12.5 kms or 7.8 miles LOS. It hosts CBC, Global, SRC and CTV among others. Only Global seems to overdrive my tuner, CBC and SRC don’t give me any grief.
  2. The far tower is in Herbert Corners (near Manotick), 28.3 km or 17.6 miles, and gives me among others City-TV, which is the only one I really want from that tower.

The Ryan tower is almost due north, but the Herbert tower is at 130deg. Soooooo, I pointed my antenna, a Clearstream CS2V (no amp, straight signal, down a 100’ of RG6 but not quad shield, 20’agl), toward Herbert, the Ryan tower is then behind my antenna and to the left, which I figured would attenuate the signal enough. Right now the CS2v is rooftop mounted lashed to, but fair above, my chimney, this last is inactive most of the time and wasn’t relevant in any of my troubleshooting. If I put the CS2V in the attic, I can’t get Herbert (City-TV) because there’s too much of my own house in the way.

Here’s the catch: Rabbit ears mostly solve the pixelating Global TV issue, not 100% but we’re getting there. CTV, CBC come in fine, but Herbert is absolutely out of range, where I’m guessing there’s too much ground clutter for the lower rabbit ears.

I’ve tried attenuating the signal in various ways (splitters, known lousy cables, multiple good cables, etc.) and the results are totally inconsistent from one trial to the next, and trust me when I say I was methodical. The attenuation sweet spot SEEMS to be around -4db (as indicated on the splitters), where Herbert remains mostly unaffected and Global doesn’t pixelate as bad… thus indicating that I’m on the right track in a way.

Throughout all this, my TV tuner doesn’t pixelate with any setup, but I have to run a 30ft cable (ya know, the lousy cable from above?) to it, so this may be enough attenuation to fix Global, nevertheless, TV seems to play all channels live just fine. On a lark, I used that same cable to the Tablo but didn’t fix Global and crapped out CBC down to 3 orange dots and lousy signal (and some outright cut-outs).

I read jimzix excellent post, yet still, I’m at my wit’s end. I’m starting to suspect a 2-fault scenario here.


Here is an example of a very inexpensive “outdoor” antenna that is working very well in my “very strong” signal location. I got it for my daughter’s house and mounted it in the attic, about 30 degrees “off target”, and it is delivering flawless reception.

As an aside, it is very, very light weight, and I don’t think it would last even a couple inches of snow or freezing rain. The included mast is very light, too. Also, it is advertised as an “amplified antenna”, but it neither comes with the requisite “power injector” nor do the illustrated directions show one. I suspect its “amplification” comes from the passive reflector elements. But, for $15, including the mast, cable and mounting hardware, I wasn’t expecting too much.

It works great for UHF, and is supposed to work for VHF-Hi Band (chan 7 to 13). I cannot test for that as our one VHF station is about 100 degrees “off target”, and about 40 miles away. Its program content is repeated on a local UHF translator, which is received perfectly.

Her house is heavily shielded by other homes in the neighborhood, all of which (including hers) are wrapped in aluminium siding. This stuff caused many reflections on flat panels and rabbit ears at mounted by the TV.

Putting this little antenna in the second story attic, reception has been great. Now, I’m trying to convince her to have the annual “big game” party at her house!


I solved my problem by getting rid of the omnidirectional antenna(on the Tablo system) and aiming the the Clearstream antenna as close to the coordinates to WGRZ in Buffalo as I could and adding a Wineguard preamp . Still don’t get CITY but now Global is fine. I ran the omni directional antenna directly to the TV and CITY is there if I want it.

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Thx jimzix!
Right now I’m testing a -6db attenuator module (not just cobbled up cables & splitters) to see if that solves anything (a cheap enough test). Seems to help, for now, but will let it go for a few days and see about weather impact.

I will look at another antenna and setup next, like the one you suggested. They’re a bit more expensive in Canada, and that’s even the cheapest crap.

Ok fresh new problem (or same problem, but new data)!

After installing the attenuator (test 1) and going to a cheap antenna (test 2), Global has settled down enough to become watchable, still at 5 green dots. But, CTV and CBC have now dropped down to 3 orange dots…

Here’s the catch: according to TVFool, they are all broadcasting from the same tower!!!
CBC -24db, (but it’s now down to 3 dots + drops and pixels)
Global -27db (FULL 5 green dots and no more drops)
CJOH (CTV) -28.3. (and it’s also down to 3 dots + drops and pixels)

So Global is between the other two in terms of power and still comes in on the verge of overdrive… the other two have simply gone to crap.

I’m starting to suspect that the TVFool database is just plain wrong.

What say you? (and thanks again for the feedback so far, it’s been useful!)

TVFool is often wrong. The Buffalo channel 4 tower has moved off of Grand Island and is now transmitting again from Colden (where Channel 2 and Channel 7 are.
All on the same tower does not mean all on the same antenna nor does it mean all at the same power. So you could have one so strong it overdrives tuners and another so weak the swaying trees will break it up.

Aw man! Thanks yardbird. Good insight. So the listed powers are then suspect too. At least now I know that a whole other line of inquiry and testing has opened.

I had the same issue off the CN tower which is 5km from chez nous. Try aiming a hair off the tower. I have checked TV Fool against a couple of sites and their coordinates are correct. How far are you from the tower? I strongly reccomend this antenna. It is very well built and picks up a lot without the attenuater. Even more with. I am using C clamps to mount it to my balcony railing. I would mount it to the house if I was able to. I got some great (free!) advice from http://www.theantennaguys.com/ . I offered to hire them for a couple of hours and the advice they gave(ditch combiner and omnidirectional and aim for farthest signal with pre amp) did the trick. Also check out this guy on Youtube. In this video he reviews the antenna I have which I bought from a guy at work because he did not need it. He has many good videos though. And he responds to email inquiries.


I have the same antenna. God bless the CS2v, it rocks… It’s pointed south-east, whereas my one channel that overdrives my tuner is to the north. But the other two channels oon the same north tower clearly don’t have anywhere near the same power output - contrary to what TVFool says that they should be within spitting distance of each other -db wise. I think those numbers are just plain wrong at this point.

I completely agree that repointing the antenna does do something, in my case it either makes Global overdrive MORE, … or if I can get it to settle down then I lose the 2 channels others off the same tower. It’s getting frustrating.

Other factors to consider: sometimes, various stations on a common tower will “combine” their signals on a common, broadband antenna. Other times they each have their own antenna on the tower. This means the antenna height above ground will be different. The changes the “effective radiated power” (ERP) of the station. Also, if the antenna is not mounted at the top of the tower (or if the transmitting antenna used is directional) the power sent in your direction will likely be different from published values. In the states, the FCC will frequently mandate that the station “protect” (ie: reduce the power sent to) an area. This is very common with stations along the US border, in keeping with international agreements.

Thanks, jimzix. Indeed I concur with what you’re saying. When I realized the data from tvfool wasn’t giving me enough info I went hunting for the specs on Ryan tower. Found an old channel attribution and location, and other documents showed signal wattage.

Turns out Global may be near the bottom of the tower, although above the tree-line and likely punching out 145KW, CTV in the middle of the tower in the vhf-hi range and in the tens of KW (can’t look it up right now), but it was not even a quarter of 145kw, finally CBC is atop the tower, highest position, but the transmitting power that I found online makes no sense with what I’m experiencing.

So you’re right about position and ERP. Although that’s what I though tvfool was giving me with the -db power and me having to specify my antenna height. There is precious little reliable info available out there.

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Hi etzmatch1, I am also in Gatineau (Old Gatineau). Thursday evening was a bad night for me with Global. I had 4 Tablo reboot from 9:00 to 10:00 pm and I had to stop all other recording from Global that night. I didn’t had the time to check the signal quality thursday night, but on Friday morning the snr on my Samsung tv for Global was all over the place, from 22 to 29 db. Today the signal is back to normal around 30 db. It looks like Global is having transmitter problems this week. It might be good to redo your test today, to see if you still have problem with Global.

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