Gen 4 OTA Recording split

I have a Gen 4, build 2.2.52 that has been rock solid for a while now with one exception. There is one program I record on an OTA channel (RF 19) from 6PM to 6:30PM PDT that breaks up into 2 recordings every single day, about 1/2 way through. This has been consistent through several iterations of firmware and app updates with the same result. The curious thing is that other programs (even hour long programs) on that same channel on the same day do not split nor do any other programs on other channels. I do have an indoor antenna (no other option) but the strength indicator is 3 green dots for that channel, the internal amp is off and I have an LTE/5G filter inline. I do live in an urban area and moving the antenna around and/or enabling the amp gives the same result. I was thinking some sort of interference occurring at the exact same time every day could be causing it, but I don’t know how I can determine that. If @TabloTV would be interested in taking a look at what is happening to make sure there isn’t something else going on, I would welcome them looking into it. I’ll keep the recordings and put it into remote access mode if your are interested. It just seems very odd that it is so consistent and I have no other way of troubleshooting it.

Since it’s the same program, do you know if the resolution is different on that versus the other programming?

Well, it’s the same channel and subchannel, which always broadcasts in 720p. I don’t know how to determine the resolution of the programming source. Is that what you’re asking?

Some of my main channels switch between 720 and 1080, so I was wondering if this was the case for what you were recording. I guess the only way to figure this out would be to check this from another TV. Too bad the Tablo doesn’t provide that information.

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Any switch in resolution can cause loss of synchronization that the Tablo has to readjust to. That should never happen because each channel is responsible for and should upscale or downscale all received data to it’s native resolution.

The data comes from multiple sources around the country/world. Up or down scaling, inserting filler frames or dropping frames to maintain synchronization of the transmitted data stream when switching sources is required for Tablo to maintain a lock on the data stream. Some channels have not implemented all of the tools needed to maintain synchronization until they upgrade to atsc3.

Loss of sync will cause Tablo to start circling while searching for the sync frame.

A weak signal can also cause loss of sync.

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I get what you’re saying, but I have seen my TV give me different resolutions depending on the show. For example, switching from an infomercial to the news. I should note that I only use my Tablo for live TV and this previous behavior was months back. However, your point has me wondering if there’s some switch in the broadcasting that could happens right as the recording begins, causing those sync issues others have mentioned. Since swapping out drives I have not had any sync problems.

@wkh While flipping through channels using my TV’s TabloTV app I did come across different resolutions. By tuning to a station I was able to see note that stations’s resolution… 480, 720, and 1080. If you’re using the app straight through the TV’s OS, maybe there’s a way for you to do the same?

One thing to keep in mind is that all programming comes from different feeds. Sync issues normally occur when the channel is switching from one feed to another. Most of the channels, like H&I, get their programming from a centralized network that handles all of the switching and synchronization between feeds. The local channel handles switching when moving from the network feed to local commercials.

Independent, non-network channels are a different case. There, you could be watching a program from one feed and the channel can switch to another feed to pick up the next program at the end of the one you were watching. Bottom line, independent channels are the most problematic because of the switching being done locally.

Your mention of swapping out drives reminds me of drive requirements. Not all drives are equal. The power requirements can vary widely if you are using one powered by the usb port. I have drives that call for 1 amp and others need less than half that. A high powered drive can point out power supply issues by overloading the power supply.

It would be nice if @wkh can determine if his problem channel is an independent or network channel.

As far as channel resolutions go, I find that the primary, xx.1 channel has the highest resolution of all sub channels.

There is no switching in the program I’m having trouble with at the point it happens. It crapped out about 16 minutes into a BBC World News America segment where they were in the middle of an interview at their studio desk - no commercials, no feed switching at that point. The 2nd segment picked up several seconds later with the same people talking at the studio desk. As per the suggestion by @269587 , I looked at my Firetv information while playing back both segments, just before the break and immediately at the start of the second segment. The feed was consistently 720p on both segments. I’m leaning toward some recurring interference at ~500MHZ happening around 6:15PM PDT every day. The picture did pixelate badly at the end of the first segment. It’s our local KPBS station, airing BBC World News America, with no feed switching where it happens. There is also no external HDD. This is with internal memory.

Much better explanation. Do any of the other sub channels on rf 19 mess up? All 4 channels on rf 19 should suffer the same.

Are you anywhere near the naval base?

I can try recording one of the other sub channels at the same time to see if it experiences the same thing. As for living near the naval base, pretty much everyone in downtown San Diego does :).

If it’s san diego are you saying the BBC World News broadcast on 15-2 at 2:30PM and 5PM also crap out the same way.

I was only recording the 6PM on 15.1, but set it up last night to record the 2:30PM and 5:00PM on 15.2 to see if it does the same thing. I’ll let you know how it goes. Thanks.

I was expecting you to have 2 things recording at the 6-6:30 timeframe. 15.1 and 15.2 will work. I’m leaning toward outside interferance in the form of a high powered, burst data transmission that can happen around military installations. If that’s the case then it could be a problem for nearly any channel that you might be tuned to.

This user sounds like they live on the bay side of point loma. SPAWAR is on the west side of the point and broadcasts toward the pacific.

The submarine base is close to the runways of both lindbergh field and coronado naval air base. If they did burst transmissions at 6:15PM everyday, we would be spending all our time fishing plane parts and bodies out of the bay.

But you never know. But certain parts of point loma are in the flight path. I wonder if there is a plane landing at 6:15PM every day.

I know CBRS wireless radios sit in the same range as Naval Radar. So if those users are close to the coast and a naval ship floats by… Their signal is gone.

Doesn’t VHF/UHF freq sit in the same range?

I’m not at all familiar with San Diego. Your point about a plane landing at that time makes more sense. I would hope that our military would know better than to send a data burst at the same time every day.

My radar and EW work ended in tha late 60s. The radars back then were in the gHz range. They did interfere with am radio only when rotated toward the receiver. EW, jamming was always broad band and would scramble tv screens even when the source was miles away.

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planes land east to west coming across hillcrest. But they take of east to west across point loma. And the take off flight path varies. It use to be so low you could shoot the plane down with a BB gun.

The SUB base is at the entrance of the narrow channel into the bay. talk about container ship wreckage to pick over for freebies. Hopefully they won’t ram one of the 3 aircraft carriers parked across from the SUB base.

I set up that too. Just didn’t mention it. This discussion is going a little off into the weeds for me.

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The weeds here didn’t grow too tall. A couple of old geezers like me could easily break into a conversation about why Ben Franklin didn’t get electrocuted doing his kite/lightning experiment while we weave our way to solving a problem. It sometimes takes a trip into the ozone layer to resurrect some old brain cells that hadn’t been called on for years.

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