Strange signal issues

Thanks for the tip - the HDB8X as a low cost alternative to the DB8e.

BTW I spent several years in Wisconsin working in LaCrosse 30 years ago. Used to go see Packer and Badger games (in Madison).

@SophieCat

Interesting… thanks for the info.

Chas

This is interesting. The Tablo does get pretty hot. And the glitches kind of do seem worse when I’m recording multiple shows at once.

I suppose a laptop cooler would be a cheap way to test things. They are usually USB powered so could I plug it into the 2nd USB port on the Tablo?

I have my cooler on order with the exact same plan: plugging into the unused USB port. I can tell you from experience (I worked with demodulators) – their sensitivity always decreases with increased temperature. The question is by how much? The cooler should at least let you somewhat rule temperature out of the equation. Good luck.

Have you tried hooking the antenna directly into the TV? This would bypass the Tablo as a quick and easy test to see if there are signal breakups APART from the Tablo.

Simply elevating the Tablo to provide air flow beneath it might be worth a try and will cost you nothing. Placing two slats of approx half inch thick wood or plastic under each end of the Tablo will allow air to circulate beneath it. My Tablo gets fairly warm this way but not HOT. The Tablo cools internally via a heat sink attached to the bottom plate which accounts for the heat build up felt there. This avoids installing a fan. Apparently Tablo design engineers felt this was adequate to the task of protecting the circuit from failure due to excessive heat.

I haven’t tried that but the problem is kind of intermittent anyway.

I did have my Tablo standing on the edge to try and keep it cooler.
I bought a cooling pad last night and it’s plugged into the Tablo. I’ll see how it does when I have multiple shows recording next week.

In more cases than not, antennae height will help. Exceptions? Of course, but few and far between, IMO.

Another thing that folks may differ about is adding various antennas placed around in different locations using Y’s. Can that sometimes create phase cancellations? Sure, but it also sometimes helps those iffy channels.

And since most people struggling with reception probably already have couple antenna’s laying around, what’s the harm in trying?

Always, always test your antennae installations directly into HDTV tuner. Tablo is simply not the best way to qualify and monitor signal reception.

Phase cancellations can be entirely avoided if using selective combiners such as a Jenca (which is inexpensive - about $25). Phase cancellations occur when signals for the same station arrive from different directions. In most cases a DB8e type antenna is pointing at two different directions (typically wider than 45 degrees) from which the same station is not seen simultaneously on both parts of the antenna. In the OP’s case, the latitude between the disparate stations is much greater that 80 degrees so a simple two dollar splitter\joiner should work.

Realizing that the OP’s problem is intermittent and may not be worth an antenna re-arrangement, the good advice in this thread by many responders may be of interest to other posters who are having similar but graver problems of alignment (variety of broadcast towers scattered geographically).

ATSC 3.0 BTW is also meant to address this dispersion of signals because of mobile reception and moving antennas…

Channel Master used to have antenna joiners for negating phase cancellation known as the “Jointenna” product (through which one specified which channels\frequencies would be let in through a port). These are no longer manufactured by Channel Master. They were $35 each. The Jenca has the advantage of allowing multiple signals in per port along with more than two inputs (thus allowing two or more antennas to be joined).

It may be too early to say for sure but since using the laptop cooler my issue has gotten much, much better.
I still experience periodic, momentary pixelization but it’s not as bad as it was, the CBS station being the most noticeable. I watched 2 hours of shows recorded Tuesday night and there were only a couple of minor glitches late into the 2nd hour. Now, there was severe weather in the area that night and the radar image on the screen showed the big red blob right near the area that stations transmitter is.

I know someone said that rain doesn’t affect the signal but on stormy nights CBS has been unwatchable for me. Could be the wind though.

Now, when I first installed the laptop cooler I turned the fan speed down to keep the noise lower and was disappointed to see the same glitches. So I turned it up to max and that same night, shows recorded after I turned it up had little or no glitches.

I’m glad you’re seeing some improvement. This is the cooler I used. It’s got larger fans, so it’s not too noisy. Ideally, something that regulates airflow based on a temperature sensor would be ideal, but I didn’t want to go crazy.

Mine is pretty similar and I paid about the same. It’s not terribly loud.