Disappointed with 4th gen Tablo’s tuner. I have channels that need the amplifier on to come in, but with this extra gain, that extra gain overloads the stronger stations so they break up and lose sync. Regular TV has no problems with the weak or strong stations, they come in fine regardless. Recently did a side by side test Tablo and HDHome Run box. Both share the same antenna feed via a splitter, and the HD Home Run operates fine weak or strong stations, while Tablo has the same too weak or too strong signal problem as before. Both work with Firestick, both Ethernet connected (and Firestick too). Tablo fails at RF gain range.
1 Like
Does your antenna have a built in booster? And is the Tablo booster turned on? If yes to both they can play havoc with the signal. If yes to both, toggle the Tablo booster off. And yes Tablo admits their signal is split to either 2 or 4 and is not very robust.
1 Like
What you are seeing indicates that the Tablo receiver Automatic Gain Control doesn’t have enough dynamic range for your conditions. You have to determine the best angle for pointing your antenna. Pointing directly at the antenna farm is generally not a good idea. Having million watt transmitters grouped together can be a problem if some are transmitting on adjacent frequencies. I had to turn my antenna 30 degrees off axis to avoid the problems created by the FCC.
I would try turning on the amplifier then move the antenna away from the high power channels so the high power stations no longer overdrive the Tablo receiver. Then check the low power channels.
1 Like
No external amp. TV transmitters are 20 miles away line of sight. Booster off and a 6 db attenuator works for 5.1. Needs no attenuator and Tablo booster needed for 6.1. No problem with the other off the air tuner, HDHome Run.
1 Like
Is this an intermittent issue?..is it occurring all of the sudden/out of the blue? What is your min and max distances from the towers you want to receive from? Also, please share your antenna setup including coax and ZIP Code if you don’t mind.
At 20 miles you shouldn’t have any issues regardless of how Tablo compares to another device.
Occurs 4 or 5 times an hour, has been doing that for at least a year. 20 miles to Mt Wilson. 90631. The only differences i can see per RabbitEars.Info - Signal Search Map is 6.1 is slightly weaker than 5.1. Outside antenna, coax with no amplifier.
Great info, thanks. What type of antenna are you using? If channel 5 and 6 are the main concerns …
Channel 5 is 600’ higher (AMSL) than channel 6. Also, channel 6 is a weaker channel overall. You can see in the topographic profile maps that there is a slight peak very close to your ZIP Code that could cause a problem. You might try pointing your antenna slightly upward 5º to 10º.
Channel 5 = 442’ AGL; 6140’ AMSL; (1053804)
Channel 6 = 113’ AGL; 5541’ AMSL; (1213941)
Yes, everyone probably agrees that the same antenna and coax should yield the same results on different devices, but not all tuners are made the same. If you don’t mind, please provide more info on your antenna, because at this point I think that it could make/break the signal for the Tablo.
Bought a Winegard HD7694P Outdoor HDTV Antenna - Long Range 45+ Mile - High-VHF/UHF - 4K Ultra-HD Ready - Free Local Channels - NextGen TV Compatible. Bought Feb, 2021. Still, the old Sony KDL 52S4100 TV channels come in fine, as do channels on new HDHome run device. Problem is the intermittent glitches on the Tablo.
Maybe before writing off the Tablo you might check with @TabloTV to see what they recommend in such situations. You seem plenty close enough to the towers, albeit they’re very high up and could be slightly blocked by terrain, so you should be able to receive a pretty solid signal with that antenna at 20 miles.
I think it is more like a tuner gain/overload issue than an antenna problem. As the same antenna feed works properly with the HDHomeRun, the signal itself is probably fine. If adding the amplifier fixes the weak channels but causes the stronger ones to break up, the Tablo tuner may simply have a narrower usable RF range. A variable attenuator could be worth trying on the Tablo input, especially if you can find a level that keeps both the weak and strong stations stable.
1 Like
If you’re very close to your broadcast tower, it may be worth a shot to turn off the Tablo’s TV amplifier.
Unfortunately, the Tablo does not seem to have any automatic gain control like the higher-end TVs. It simply has a front end RF amplifier that adds 6db to the entire frequency spectrum. It’s either “on for all” or “bypassed for all”. Having AGC for each of the 4 internal tuners would seem too complex ($) for such a relatively inexpensive device.
My 12 year old Sony Bravia has a very good AGC functionality ahead of its single tuner, as do other higher-end TVs. It actually dynamically adjusts gain as each channel is tuned, and continues to do so while watching. This is easy to see in the Sony’s very robust signal diagnostics screen. Needless to say, of my 4 TVs and Tablo, it is by far the best performer when going after broadcast TV.
Having a mix of “hotter” RF signals along with “weaker” RF signals can be handled much better by a good “traditional” TV than by a multi-tuner $100-ish Tablo. The Tablo just doesn’t have the capability to sort this issue.
As others have posted, the OP may have to resort to other means of “balancing” the signal levels before they get to the Tablo. Pointing a directional high-gain antenna off-axis from the hotter transmitters and more directly toward the weaker transmitters could help. Using an antenna with an internal amp that splits the VHF boost and the UHF boost (Televes BOSS) might help if the weaker channels are UHF and stronger are VHF. Using specific frequency attenuators on the “hotter” channels upstream of the Tablo might work. There are even digital processors like Avantx and Smartkom (Televes again) that can digitally combine signals from multiple antenna feeds and “equalize” the signal levels across all channels before outputting a feed to the Tablo.
It’s only time and $$! 
Edit:
Here are the 6 RF transmitters I send to my Tablo and 4 TVs via coax. The transmitter on RF channel 10 (Hi VHF) is highlighted in blue on the meter at -35.5dBm. The other 5 transmitters are on UHF RF channels and are pretty close to that same level. These 6 transmitters cover about 30-ish virtual channels in my area. There are more transmitters available but I filter them out (don’t want them in my channel scans). I actually only use ABC, NBC, CBS, FOX, CW, and PBS. I skip the rest of the “junk” virtual channels after the channel scans in the various TVs and Tablo device settings.
2 Likes
I do turn off the amplifier to get the stronger signal, but signal is still too strong. Adding a 6dB attenuator works, but then the weak signal needs the amplifier to work. I don’t like having to add and remove the amp every time i change channels.
1 Like
Does someone make an external AGC box that could be put ahead of the tablo?
1 Like
Some Televes antennas feature a a close-coupled amp (BOSS) that automatically adjusts gain for both VHF and UHF bands independently and continuously. This is a step in the right direction, and is very effective for situations where the signal levels on one band are uniformly different than the other. Sort of a 2-band equalizer.
However, in situations where RF channel levels within bands vary dramatically, you still have to use other approaches (like I suggested previously) to balance things out. I happen to use the Televes Avantx digital processor which is on the high end ($400) of ways to have significant control over the RF side of OTA TV. The Televes Smartkom is $100 less and essentially has the same capability of digital RF filtering/balancing (32 user-assignable filters).
Both of these devices are very effective tools to solve specific problems. They are also expensive. (Both can also properly combine coax feeds from multiple antennas).
1 Like