Inconsistent antenna reception

Recently my reception has become strangely inconsistent. One moment a program looks fine and the next my Tablo tells me the signal is too weak. Tablo records a program at 8 with no problem but fails to record a program on the same channel at 9. I try to view a program on my PC (ethernet) and Roku (wifi) upstairs but the signal is too weak. I go downstairs to a Roku (ethernet) on the same network as the PC and it looks fine. The channel scan shows both Fox and PBS as 5 green on one scan and then can’t find either channel on the next. I have a two channel Tablo (2016) with a new Winegard FL5500A powered antenna. All of the broadcast antennas are on a mountain about 21 miles to the southeast and my antenna is in a second story window facing southeast. I have had this set up for about 3.5 years and this problem has only started recently. Why would a signal look great one minute and than suddenly disappear completely the next?

You’ll get a whole bunch of reasons! First, does this fluctuation happen directly from a TV?

Something between you and then broadcast antennas could have changed over 3.5yrs. How new is your powered antenna? 3.5yrs ago, did you have a non-powered antenna which worked ok? Maybe an “over amped” signal? I’ve encountered this on just one channel. Things like cell or other transmission towers in the area, either new or making adjustments. “Change of season” anomalies. Loose connection/bad wire. Powered part of window antenna no longer functioning, rendering window antenna useless. Tablo “on it’s way out”.

Then there’s the repack arena. You’ll be asked to do a channel rescan - and make sure you click [add to guide]. Don’t forget to reboot everything attached to your network, one by one (kind of just because). Then you should consider contacting tablo support, open a ticket, email, or phone - during business hours.

Tablo on its way out seems to be the logical conclusion since none of the others seem to explain the inconsistency. I would expect environmental changes over time such as new cell towers, other new construction, tree growth, etc but I would expect the effects to be observed consistently and not come and go. I replaced the original antenna recently (baked in the sun for 3 years) because of these issues but it didn’t get rid of the problems.

1 Like

Were all the people in your house in the same location? People are an object and can cause signal to bounce around them. Was microwave, air conditioner / heater on? Does your antenna have a splitter on it? Tablo has an internal 4 way splitter, so that could be making it weaker (but if it is 5 green sometimes, that’s not it). If there is a splitter on the antenna, and there are ANY connections not connected to something, there should be a terminator cap on them. If you don’t know what I mean, let me know and I’ll post a link to them in Amazon.

1 Like

There is no splitter so I don’t need a cap but I can’t answer the other questions. This was happening during the cooling season so the air conditioners are always on but that has always been the case.

If you have trees nearby, perhaps the wind is blowing the branches causing the signal to drop. Also, if you’re consistently seeing a drop off at a certain time, perhaps there is other radio traffic in the area that messes with you. Are the affected channels on low-VHF (real ch 2-6). These low channels are highly susceptible to sunspot activity, which is most common during the summer and fall, but can occur any time of year. Since TV has moved to “only digital” transmission, sunspots which used to “interfere” with analog reception can now cause a total drop out of the channel.

Perhaps a cab, ambulance, public service vehicles were talking on their radio. Air ambulances must have a VHF portableradio programmed with both the Hospital-to- Ambulance WHITE (155.2800 MHz) frequency and the Air-to-Ground TAN-VMED28(155.3400) frequency .

This post from the Tablo blog explains some more:

“I have a two channel Tablo (2016) with a new Winegard FL5500A powered antenna.”

I suspect that there is too much signal coming out of that antenna’s amplifier. The Winegard amplifiers are usually 20db gain which amplifies the signal by a factor of one hundred (100).

So if you were not using an amplifier with your old antenna and had good reception then you now have increased your signal level way too much. The Tablo seems to be a little more sensitive to high signal levels then television sets.

The cheapest way to confirm this is to purchase attenuators (pad). I would start with a 10db pad in the RF line to the Tablo. That would reduce the signal by a factor of 10, leaving a gain of 10 from the amplifier instead of 100.

You should see some improvement if the amplifier gain is the source of your problem.

Why do you suppose, after over 3yrs, the antenna’s amplifier suddenly began to put out too much signal?

…just one of those things?

In his original post rekwin wrote:
“I have a two channel Tablo (2016) with a new Winegard FL5500A powered antenna.

Right, which they’ve claimed worked for for +3yrs

Just asking, for trial and error, saving some hassle - I’ve heard about amplifiers dying… but suddenly over working?

It may be that rekwin meant that his 3.5 year old setup included the "new Winegard FL5500A powered antenna.”

But I don’t generally refer to 3.5 year old equipment as new.

So I assumed that his 3.5 year old setup included everything but his "new Winegard FL5500A powered antenna.”

I put in the new antenna because we were having these reception problems. The old antenna was an Amazon Basics powered antenna identical to the Winegard. The old antenna had been baking in the sun for 3 + years so I thought it was time for a change. Initially it seemed the new one improved reception but then the same problems started happening.


I have picked up those attenuators which I mentioned above for 2 or 3 dollars each. If you can get them cheap then buy a 10db and a 20db pad. Use the smallest pad that works for you.

That makes for a very cheap test before you toss your Tablo into the trash.

Signal overloading can be very confusing.

A strong incoming signal running into an amplifier then gets even stronger and can overload the front end of the television tuner. A television tuner has automatic gain control circuitry (AGC) to increase the signal for the rest of the set. (Usually one of those AGC stages is before the filtering done for selectivity.) A very strong incoming signal can cause the AGC to reduce the television’s internal signal gain to the point that weaker channels no longer have enough signal.

UPDATE: Television stations around the country have been ‘repacking’ this year and I have noticed that at least one of the ‘repacked’ stations is coming in stronger than before. That could explain the change which you noticed.

Good luck.