Pixelation, signal shows five green dots

#1

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.

#2

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

#3

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…

#4

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.

#5

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.

#6

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.

#7

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.

#8

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.