Help -- Tablo Affecting My Happy Wife and Happy Life


#103

Do you have cell towers nearby? I have one within a mile and a half and had weird issues and found I needed an LTE filter on my antenna.

My immediate response to this is yes, because I have an app on my phone that supposedly shows what tower I’m pinging. I noticed months ago that when I’m home it was supposedly pinging a tower within a half mile or so of my house. I thought I even remembered spotting it on Google Earth. Now, at work, where the app isn’t pinpointing its location, I can’t for the life of me find it on Google Earth by just panning around where I thought it was, and every “cell tower locator” website I’ve tried isn’t showing any as close to me as I know this app was reporting. So the short answer is actually, “I don’t know. I’ll check it out again when I get home tonight.” But that’s a good thought if that gave you problems.

Some FM transmitters, if nearby, can also interfere. If that happens you need an FM trap.

FM Fool reports that the nearest transmitter is 12 miles from me.

Is your antenna outside and clear of most anything around it? Signal REFLECTIONS can do what you’re seeing as well. A nearby house on the backside of your antenna reflecting signal back to it (now out of phase) will give you multipath issues.

In my estimation, my antenna is clear of anything that I would think would be interfering with it. It’s mounted on the highest point of my roof with no obstructions in the immediate area.


#104

yardbird,

“I think most modern tuners are far more tolerant of “too much signal” than they were a decade or 2 ago. You’d have to really bash the new ones to get them to the point of being overwhelmed. The AGC is pretty capable of squashing a hot signal.”

This is true for Television sets. I have inserted attenuators in my TV’s RF input coax line and seen very little change in the signal strength meter for the strongest signals. (That is what the automatic gain control circuitry is designed to do.)

But it is not true for a Tablo. The graph below comes from the Tablo webpage here:
See: https://www.tablotv.com/blog/getting-technical-over-air-tv-reception/

Notice that they show the Tablo’s normal input range as -50dbm to -80dbm. (The -50 dbm is the strongest signal end.)

The ATSC guidelines for receivers give a range of -5 dbm to -83 dbm. That is a much larger range than the Tablo.

BlueCalcite is in a very unusual situation where he was getting still video (freeze ups) from time to time after the foliage fell off of the trees in his line-of-sight to the Cleveland transmitters. Tvfool was indicating reception problems by showing RED to Orange in Medina. The Green area was very small and behind a hill or ridge in his line of sight.

See my comment numbers 14 and 16 above.

Please do not advocate on his signal strength issues. His reception problem was real and it was unique. I have certainly never seen one like it. When he bypassed the 15db amplifier and installed attenuators, his Tablo operation improved.

But he does seem to have some additional problem. And I certainly have not been any help with that.

I doubt that the problem is cell phone towers since his Tablo performed well for at least 4 months until about November 2018 and then got progressively worse. (Just after all the leaves had fallen.) I doubt that his problem is erratic multipath too, and for the same reason. (those 4 months)

The most likely cause would seem to be that his Tablo has developed an intermittent problem which occurs randomly. I worked on audio, video, RF and digital electronic hardware for over 32 years and I hated intermittent problems.


#105

Cell towers are often “owned” by companies who are NOT the cell carrier. As such they often have additional antennae on them for instance communication antennas for business use, microwave relay antennas, all kinds of stuff. They don’t all broadcast all the time. Unless you’re in an area of tall buildings, on your way home look for a tower. I spotted the one near me that way. It’s on a dairy farm. I was able to look up the operator, see the transmit frequencies, and there was a way to see if any of those were harmonics of the UHF channels I was getting.

That FM tower at 12 miles I don’t think I would be concerned about at all.

How close are you to the TV towers? The closest ones.

Think of the UHF broadcast coming toward you like a breeze. Anything between you and the transmitter disrupts it. It’s very line-of-sight. I had a line of trees… well actually… it’s the extra lot owned by a neighbor that she wants to remain “forever wild” and the trees start about 15 feet from my house. When they’re leafed out they create a UHF “shadow”. In winter I had no problem with reception unless really windy. I moved my antenna to the other side of the house (other end?) and got it about 50 feet farther away from those trees. My signal improved dramatically. It’s still technically in a “shadow” but it’s kind of like the breeze analogy. It’ll fill in some after the disruption. It’s not a smooth unobstructed breeze any more, but you can usually find a spot where things have come back together enough to be useable. This “breeze” is also layered. Alternating layers of good and weaker signal (horizontally) and sometimes you get a better result raising or lowering your antenna (yes lowering) as little as a couple feet to position it in an optimum spot in the layers. This is like fine tuning, but in cases where you’re having issues, maybe a little fine tuning is all that’s needed. I’ll be experimenting with mine again once the weather warms up. I moved it when it was brutally cold outside and now that it’s working pretty well I’m leaving it alone until it’s easier.
And sorry this is so wordy but you see what I mean? This is both simple and not simple. Some people can slap an antenna in their attic or on a window and they’re fine. Others need to find a sweet spot where it all works.
I have a hard time believing you need all that attenuation. If you suspect you have a hot signal, you add a variable attenuator. You turn it all the way down (no attenuation) and slowly start turning it up (adding attenuation). At some point you should see your signal IMPROVE. Why? Because it’s no longer hot and your tuner handles it. If the signal goes DOWN, then it’s possible you don’t have a hot signal at all. I know that sounds a bit counterintuitive, but it works.
I see you’ve bypassed the preamp. Are you splitting the coax to go to other TVs and the Tablo? Splitting inherently adds attenuation. A 2-way splitter drops about 3.5db, a 3-way drops 5.5db, a 4-way drops close to 8db So a 4-way distribution amp that adds 8db is really just replacing the splitter loss. And none of them “clean up” the signal. If it’s a crappy signal whether interference or multipath or whatever, they just amplify the crappy signal and make it extra crappy :slight_smile:
I’d ditch the attenuators until you know exactly what you’re dealing with.


#106

Since the dual lite has a newer tuner and demodulator combo compared to the original 4-tuner, would that model possible have made his wife happier?


#107

And… I just saw JimH’s response. Some information I didn’t have and… all bets are off. Certainly a unique situation


#108

I doubt that the problem is cell phone towers since his Tablo performed well for at least 4 months until about November 2018 and then got progressively worse.

I wonder if a new tower could have been erected around the time I started experiencing problems. It seems a new state law has them popping up everywhere, with little ability for the city (and obviously none for the residents) to stop them. The one that is the subject of this article is about 0.75 miles from me. I’ll have to do a driveby to see if it was ever installed there.

Perhaps the websites I’ve been looking at don’t have all of the new towers mapped yet. As soon as I get home I’ll see if I can get my phone app to tell me again where the tower is that it is pinging off of.

Notice that they show the Tablo’s normal input range as -50dbm to -80dbm. (The -50 dbm is the strongest signal end.)

TV Fool reports virtually all of my stations with signals (at my antenna, I presume) greater than -50 dBm. Several of them are around -30 dBm. I’ll have to trace the cabling to verify, but as far as I know there’s just one split to the Tablo and my living room TV directly (-3.5 dB to each, correct?), and then the Tablo, from what I’ve read, is probably two two-way splits for another -7 dB to each tuner? So would that be a total of -10.5 dB to each Tablo tuner? Or is it a more complicated calculation than that? I was briefly a math major in college, so I can do the math if the physics is explained to me.


#109

TVFool reports most of mine below -50dBm as well. One is at -19.9.
I guess we’ll see if I smoke a Tablo tuner. If the Tablo tuner is so far off spec that it can’t handle what every single TV, TiVo, or anything else receiving TV signal has been able to handle, then I guess it will be a short experiment. I’d be interested in hearing from @TabloTV or @TabloSupport as far as the current accuracy of that graph. How could you have a tuner that rejects that much signal and still expect to be a player in the OTA DVR device arena? Is it possible that graph is no longer reflecting the current capabilities of Tablo’s tuners?

TVFool also has a lot of incorrect information at least for my area. Towers in totally incorrect location, power changes. So… we shall see.


#110

Tvfool has to make certain assumptions. (Antenna gain, that your antenna is actually pointed at that tower, antenna height above ground, signal losses thru coax and probably your antenna’s height above sea level.) In your case, you have a small antenna probably with low gain, and it is pointed about 10 degrees east of the WEWS tower. You also have splitters which cause signal losses. And in the summer months you actually need a 15db gain amplifier!

You checked your RF level by attenuating it down to less than the ’Threshold Of Viewing’ (TOV) and then removed some pads. During the testing you chose to keep 18db of attenuation in the line. But now your strongest stations may be fading too much during local snow. That would seem to indicate that the strongest signal levels are a little low.

I just went back to check the level I quoted in comment 31. I stated “Using your measurements, I calculate that WEWS is now coming into the Tablo at about -49 dbm. “ But I had mistakenly included the 15db loss from the amplifier being bypassed. That 15db loss was irrelevant to my calculation.

So the actual level for WEWS was about -65 dbm. Still good enough for testing your strongest stations. Except now you are getting a lot of local snow. Which is causing excessive signal fading.

If you removed 18db of the attenuators then your signal level would be about -47 dbm. (Leaving no attenuators) I doubt that you would be overloading the Tablo. (I have one channel’s signal at -45dbm.) And this will give you a larger fade margin for all your stations.

Frankly I doubt that removing this 18db will change the Tablo operation during your testing. Because at least some of your failed tests occurred on clear days. The -65 dbm signal was certainly adequate for reception on those days and could not possibly overload the Tablo either.

This change WILL allow for a larger fade margin for the PBS channel that you like.

EDIT: That only leaves your observation that you seem to be having better luck with the Cleveland FOX station which is weaker than NBC or ABC. I believe that your ABC and FOX stations are using 720p for their broadcasts. Your observation may be telling us that there is less Tablo processing for 720p signals. (Compared to NBC’s 1080i broadcasts)


#111

I drove around the neighborhood tonight and found a cell tower just about a half mile from me at an azimuth of 15 degrees. My antenna is at roughly 38 degrees, and the Cleveland towers pretty much halfway between those. However, Google Earth historical imagery shows that tower has been there around 5 years, so unless something changed about it I doubt it’s contributing to my problem.

At this point I’m so mentally exhausted thinking about it that I’m just going to await word from Support. I put the device into remote access mode last night as they advised, this morning it was still in that mode, and tonight the light is solid indicating it’s been restarted, hopefully because they were already in there poking around. No word yet.


#112

While location hasn’t changed remember that the tv channels are changing bandwidths. That change could now be causing issues.


#113

Terrestrial broadcast stations occupy 6MHz as they always have.

We are just getting better use of the 6MHz.


#114

I understand that , but issues can still arise. I have been OTA since 02/25/2016. One of our locals moved mghz (recently) and now we are having an issue we didn’t before.


#115

I believe that you are referring to the repacking of Television broadcast stations. Most of the TV stations in my area will change their physical channels (frequencies) in September or October.

The outcome just depends on how well it is handled.

Just hoping for the best.


#116

How long does it normally take to hear back from Tablo Support? It’s approaching 5 full days since I put the Tablo into remote access mode for them to look at. I’m afraid to follow-up by e-mail since I’ve read that punts you to the end of the line again.


#117

Checking on this for you now… Replies usually get back within 1 business day but it sounds like the team needed to review some logs from your Tablo. Stay tuned.


#118

I live in Brunswick Ohio. Have 2 Roku Tv’s and an 2nd floor out door antenna mounted on a wall angled towards the Cleveland field. I have experienced no issues whatsoever with freezing. My wireless is 5G. Tablo is about 2 years old now. The only attenuation I have is one for cell phone frequency’s. I amplified 11 DB with a Channel master amp.


#119

If it’s cell phone frequency then it’s interference, not attenuation. :slight_smile: and you can fix that easily and inexpensively by putting an LTE filter in line. Put it BEFORE the amp. Like as close to the antenna as you can. So the line coming from your antenna gets LTE filtered BEFORE any amplification happens.


#120

Roku has released an update to their OS 9 that the different audio modes (leveling and night listening mode) are back under the Audio settings (Main Menu -> System -> Audio).

Just posting for those who search this issue later, should be easier to fix now if you get surround sound warnings.


#121

Six weeks of e-mails back and forth with Support and things have only gotten worse. For the past month, I’ve been logging every detail of every error, which has been a major pain in the butt to stop what I’m doing a half dozen or more times a night to enter details into Excel. I dropped the quality to 720/5 for the bulk of those six weeks, but recently bumped it back up to 1080/8 when Support agreed that it’s not related to my network. It worked great at 1080/10 for the first six months or so. I bought a new router (same model - Linksys EA8300) just to rule that out. No improvement. I still stream Sling and Plex flawlessly. The 5G WiFi signal is strong everywhere. I’ve played with engaging and bypassing the 15 dB amp. At Support’s recommendation I’ve been using only the Preview app, which I now like better (theoretically, when it works). Still, I’ve been getting increasingly greater frequency of freezing regardless of which live channel or recording I try to watch. The freezing usually but not always ends with an error message (usually either “Failed to load video” or “An unknown error occurred”). I’ve tried not only my three 4k Fire Sticks, but my wife’s iPad and my Android phone, and the problems occur on all of them. I bought the previous 2nd Gen version of the Fire Stick again (which I used for much of last year before upgrading), and the problems continued. A few nights ago, upon turning on the TV for the first time that night, I got three consecutive different errors just trying to tune to channel 8 (“Weak Signal” > “Storage is Full” > “Failed to load video”). There is more than 500 GB of space left on the hard drive, and both Tablo and my LG TV with its own feed from the antenna report full signal strength for all of the channels. In fact, a couple months ago when I was playing with attenuators to see if my signal was too strong, it took not only removal of the 15 dB amp, but on the order of 20-30 dB of additional attenuation before the Tablo started to report less than 5 green dots for my strongest channels. The attenuators didn’t fix the problem then, so I don’t think strong signals are my problem, and I sure don’t think I have weak signals. My TV with the other split from the antenna has never blinked – perfect reception every time we’ve resorted to using it. The hard drive was ruled out long ago after trying a different (new) drive, and testing without a drive. Support can find nothing wrong with the Tablo and insists it’s an intermittent reception problem, though they haven’t been able to observe any signal issues when they’ve been in there testing.

Is there anything we’re missing? I’ve given up the last couple days even trying to use it, since it’s gotten tiresome to try to get through anything (live or recording) with having to constantly stop and run to the computer to update the log.


#122

@BlueCalcite I have to commend you, you’ve given this so much time and patience. I’m not sure I have anything else to offer, you have been very methodical in your troubleshooting thus far. Honestly, there is only a couple of other things I could possible think the problem could be.

  1. When you switched hard-drives, did you also swap the USB cable that connects the drive to the Tablo? While rare, I have seen usb cables become intermittent in their reliability. A long shot, but if you re-used this cable, it would be something easy to try. Same with the Ethernet cable that connects your Tablo to your router. Worth changing?

  2. The Tablo unit you have is just defective. With everything you have tried, can’t support send you a refurbished unit to test? If that unit still has the same issues, then it would sure help narrow the problem down to something other than the Tablo itself. I’m leaning towards a Tablo hardware issue.

Good luck, I can only imagine how much pressure your wife must be putting on you at this point :).