Tuner Sensitivity issue

I have had some issues with weak signal on a couple channels. I have an old Motorola DVR. Just for grins I hooked it up to my antenna. It gets channels that Tablo doesn’t even see. And switching back and forth, channels come in on the Motorola but I get weak signal on the Tablo.

So I’m wondering if the Tablo tuner is just not all that sensitive. I have the quad version.

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We do have a slight amplification in the tuner to make up for that split though.

@jwwhite001 - How close are you to the broadcast tower? What antenna are you using? I’m wondering if it’s actually overdriving the tuner vs. not having a good enough signal.

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The user didn’t specifically say he’s seeing the weak signal message… So I assumed he was experiencing picture issues like pixelation or artifacting.

I am seeing the weak signal message. I have an outside antenna. We are about 40 miles from the broadcast area. If I look at signal strength on my TV (wish it was available on the Tablo), all the channels are good except for a couple. Those show weak. But my TV and my old Motorola DVR will pick those up with good clear picture when the Tablo is showing weak signal. The Tablo will pick them up about 60% or the time. The rest of the time they are showing weak signal. So I don’t think it is an overdriven issue as the strong channels come in ok.

@jwwhite001 - Fair enough. Those channels must be on that hairy edge then.

Do you have an amp on your antenna?

I did try an amp. Bought a good one that cost about $80. It made no difference. If anything the weak channels were worse than they were without the amp. I ended up returning the amp. My next step is to raise the antenna up about 10 ft. But that won’t be for a few days. Luckily we don’t watch the weak channel that often, it is FOX. Missed the best part of the last world series game tho. That was a bummer. Lost signal in top of ninth.

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A bit of explanation here. I used to use the Motorola DVR a few years ago when we only got OTA signals. After we got satellite I quit using it. But if my memory serves me right, the tuner in the Motorola was better than the one in the TV. It connects to the TV via HDMI. Now that I’ve ditched satellite again, the reason I went with the Tablo was to interface thru ROKU. Saves fumbling with too many remotes, etc. Not too bad for me, but my wife…

I now have the antenna connected to the Motorola and it has a feed thru output that I connect to the Tablo. It didn’t seem to make much difference if I had the Motorola in the circuit or not. But this way if the Tablo loses signal I can switch to the Motorola and hopefully still watch whatever I was watching.

Hope all that made sense. I still like the Tablo and realize my issues are my setup and not the Tablo itself. I was just making a point that the tuner was apparently not as sensitive as some others. I did have some recording issues the other day, but after going thru that again I’m pretty sure it was my error. Time will tell.

Thanks to all who have responded with help here.

Passing the OTA through the Motorola first may give the Motorola tuner an advantage versus the downstream Tablo attached after pass-through. A really fair comparison would use an A/B switch which connects the OTA feedline to either the Motorola or to the Tablo with no pass-through involved.

Also, splitting 4 ways and adding some amplification to compensate is theoretically as well as practically inferior to a direct single feed, particularly for weak signals and typical amplifiers used in these equipments. As you already know, the real key is good antenna performance. Height, careful pointing, and a good antenna design solve these problems best.

Retired Engineer: If you read my initial post I believe I said I switched back and forth between the 2. The Motorola always did better than the Tablo. The final hookup used the passthru so that I can use either one. With the pass thru there is no apparent difference in the Tablo reception.

Different antennas and different tuners behave differently at different frequencies. For example, the DB8E antenna outperforms the ChannelMaster 4228 at higher frequencies and underperforms the 4228 at lower frequencies. That is due to the design of the whiskers and reflector. This has been determined in testing and viewing signals through a scope.

Similarly, different tuners have different chips from different suppliers. Some tuner designs behave differently from others depending on frequencies handled.

Therefore performance analysis and comparisons may be misleading. Antennas and tuners do not behave uniformly. I have several different tuners - Tablo, Hauppauge, KWorld, LG and Samsung. Each one has a different pattern of sensitivity, detection and consistency. All are 5th and 6th generation tuners.

This BTW also applies to preamps. They also behave differently at different frequency ranges. In fact I got a shock when comparing two ChannelMaster 7777 preamps, I noticed each reporting different signal strengths from the same antenna and location!

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So in a more fair comparison, the Tablo tuner does not do as well as your Moto did, and given its 4 way splitter I am not surprised. The Tablo may have comparatively poor noise figure, its ATSC decoder may have a less robust design, or as stated very well above, may have frequency or other dependencies which favor the Moto for your particular channel mix.

If you are seeking a better reception outcome, the relative performance of the Tablo compared to yesterday’s set top box is less useful than looking at antenna and possibly feedline improvements.

That is why people consider OTA “voodoo art” even though it does follow the scientific rules of RF signal propogation and Maxwell’s theorems\equations.

I had a situation at a friend’s house where 90% of his channels came in fine at location A except one. It came in fine at location B (6 feet away). If we moved the antenna in the middle as a compromise, we lost signal strength on all channels. We spent hours trying to find the optimum location for that one antenna.

Finally I said the hell with this. We put an antenna in location A, another one in location B, joined the two through an inverted splitter (which becomes a combiner) and then on to the preamp. All channels then came in perfectly through that stack.

Sometimes trying to finagle one antenna can be a test of patience and an exercise in frustration… At some point, just throwing a lot of metal at the problem does the trick LOL.

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What antenna are you using? Is it made for both UHF and VHF? If not, that could make your weak stations come in better. I used to get virtual channel 62-1 thru 62-4 with the Mohu Leaf when connected to the TV but when I connected to the Tablo I lost them. I learned that the virtual channel 62-1 thru 62-4 are BROADCAST channel 13, so replacing the Mohu Leaf with the Winegard FL5500A got the weak stations even on the Tablo and they were not as weak. I still lose them during heavy rain because of the distance between Killeen and Austin. see www.winegard.com for outdoor antennas too.

I agree with all the above comments. My original intent of this post was to point out the difference in one tuner vs the other.

One question that comes to mind. When Tablo says weak signal, is it possible the threshold setting on the Tablo might be higher than on some others? Even tho it is weak might it come in anyway?

The channels I am having issues with on the Tablo are 49 and 51. 49 comes in most of the time on the Tablo. 51 is the same network and off the back of the antenna. Which makes it even stranger that my other unit picks them up at all. Tablo doesn’t see 51 at all.

I will be elevating my antenna sometime in the next couple weeks and will see what happens then. It is not really a problem now as infrequently we watch that channel I can always switch over.

Oh, I just realized I made a dumb mistake on these posts. My other unit is a Magnavox, not a Motorola. Not sure where my brain was when typing. Sorry about that.

@jwwhite001 Check out my post here:

It should help you to get the best signal and give you some information on why an amplifier did not help.

In our case all the major network stations are in the same area. But that makes no difference to the point of this post, which was to point out that my other device has a better tuner. Irregardless of the statio locations my other device picks up more stations with better receptions.