Strange Digital Transition Problem With KTLA

[denisincalif]

Before last Friday I was able to watch KTLA's digital signal (Los Angeles Channel 5 and former superstation). Their digital signal was (and still is I believe) broadcast on physical channel 31, virtual channel 5-1. The signal was a little weak at my house. My VIP 622 and the Mitsubishi WD-73727 it feeds are connected to the same UHF/VHF rooftop antenna via a splitter. Both the TV tuner and the 622 tuner could get watchable signal from KTLA about 90% of the time, but there were occasional dropouts. Meanwhile my small Samsung TV in the bedroom, connected to an indoor SquareShooter antenna, was able to get the KTLA digital signal about half the time, with frequent dropouts.

On Friday night, and again on Saturday, and yet again on Sunday night, I deleted all my local channels from the 622 and rescanned. The results of all three scans were identical. All digital channels that I used to get are still there (some switched frequencies of course) except KTLA. In fact, the old channels are all as strong or stronger than they used to be, and I gained three channels that I had not been able to see before. But the signal strength of KTLA is 0 according to the 622.

Now comes the really weird part. I decided to see if it was just a 622 problem. So I switched to the Mitsubishi's tuner (which had also been rescanned). It can't see KTLA either! So then I figured KTLA had moved their transmitter (where I live I am very close to the mountains and am very sensitive to slight shifts of transmitter position) and that I was never going to see KTLA off-air again. It wasn't the end of the world. I get my local channels from Dish and they provide KTLA in HD. But I still would rather watch OTA when possible. Imagine my surprise when I rescanned the Samsung in the bedroom and up popped KTLA with a booming signal!

Does this mean that there is something wrong with KTLA's PSIP information, or something wrong with the way the two older tuners interpret the PSIP? I doubt that is the problem, because why would KTLA change its PSIP data just because of the digital transition? What could be going on here? Do I contact KTLA or Dish? The score right now is: one-year-old Samsung 1, the older Mitsubishi and 622 0.

 

[pro96]

Before last Friday I was able to watch KTLA's digital signal (Los Angeles Channel 5 and former superstation). Their digital signal was (and still is I believe) broadcast on physical channel 31, virtual channel 5-1. The signal was a little weak at my house.

KTLA is and has been for a while now at 5-5 OTA in the L.A area.

 

[mdonnelly]

dennis - see the article in Multichannel News where they say FCC advocates "double re-scan". Disconnect the OTA antenna, scan to clear the channel memory, then reconnect the antenna and re-scan. The say it fixes the KTLA problem 80-90% of the time.

http://www.satelliteguys.us/latest-headlines/178463-fcc-pushing-double-re-scan.html

 

[denisincalif]

dennis - see the article in Multichannel News where they say FCC advocates "double re-scan". Disconnect the OTA antenna, scan to clear the channel memory, then reconnect the antenna and re-scan. The say it fixes the KTLA problem 80-90% of the time.

http://www.satelliteguys.us/latest-headlines/178463-fcc-pushing-double-re-scan.html

Thanks. I'll try that tonight when I get home. But I am surprised that KTLA should have the problem described in Multichannel News. All the information I have been able to locate says that KTLA is staying on physical channel 31. Is that not true? Did it in fact move back to channel 5?

 

[DishSubLA]

Although the KTLA and other station across the county have been getting used to broadcasting in digital, there will be weird issues such as yours in the coming weeks and months. Local stations will be tweaking and fine-tuning and even playing with FEC in order to get it right and operate with great stability for the vast majority of viewers. There were playing around before the transition, as well. Remember, several stations will lose and add viewers post-transition. In some cases, addtional sub-channels, FEC and other encoding issues will be tweaked and solved on the fly.

As for me KTLA used to come in--before the transition--at about 78-80 on my 722 and 722K. Now I can get it at about 82-86. Clearly, some digital broadcasters left the adjacent channels. KNBC was almost barely stable at about 66-70, but now it is a whopping 89. My big problem now is I will have to spend some $$$ so that I can get the stations now on the VHF high-band. Like you, I try to use the OTA for LIL for recording because it leaves my satellite tuners free for other recordings the occur at the same time, and I love viewing as much local news at the same time as possible. At 10:00 it's 5, 11, and 9. At 11:00 it's 2, 4, and 7. In the afternoons, it's 2, 4, 5, 7, and 9. And KECT (PBS flagship) must be viewed OTA if I wish to enjoy it in HD. All those Huell Howser shows.

 

[Yes616]

Thanks. I'll try that tonight when I get home. But I am surprised that KTLA should have the problem described in Multichannel News. All the information I have been able to locate says that KTLA is staying on physical channel 31. Is that not true? Did it in fact move back to channel 5?

Here is a link (pdf) to the FCC site of coverage maps for the LA DMA and more information. On pages 39 and 40 you will see KTLA did stay on channel 31.

The maps are a bit conservative (like antennaweb.org) so if you have a good antenna with a pre amp and signal booster and you are on a hill with no trees blocking your view towards the towers, you should get better results than the maps predict.

In my area I am finding that some people are getting signals and we are about 30 miles outside the NYC coverage area. According to our maps anyway.

LA TV Coverage Maps

 

[denisincalif]

It still doesn't work

Thanks to yes616, DishSubLA, and mdonnelly for all your suggestions. Unfortunately, I am still unable to get KTLA on the OTA tuner on my 622. My Mitsubishi TV is also unable to get it.

I went through the procedure described in the Multichannel news article. I deleted all locals, disconnected the antenna, rescanned (getting nothing of course), then I unplugged the 622 (mdonnelly didn't mention that step, but the article did), waited several minutes, plugged it back in, scanned one more time with no antenna connected (just for good measure), then reconnected the antenna and scanned one last time. The results were identical to what I had before I started. No KTLA. Signal strength on channel 31 is 0. All other channels are at least as strong as before the transition. Some are significantly stronger and I can now get KCBS, KABC, KTTV, and KCOP off air using the rooftop antenna and the 622 which I could not do before. But those stations are still too weak for my bedroom TV because the antenna for it is both indoors and relatively low to the ground.

yes616---signal strength is not my problem. I get KTLA on my bedroom Samsung with an indoor SquareShooter antenna just fine now. The signal is plenty strong. Before the transition the bedroom TV had a lot of dropouts on KTLA. So its true signal strength at my house has clearly increased.

dishsubLA---I think you are on the right track. This appears to be a software problem. Clearly, KTLA changed something in their metadata for the transition. They did something that has confused my Mitsubishi TV and the VIP622, but the Samsung TV has no problem with it.

My next step will be to try to contact somebody at KTLA who has some technical knowledge to find out just what they did and if they have plans to fix the problem.

Another possibility is to see if Dish can fix the problem with a software update to the 622. I suspect that is less likely, since the problem is specific to just one station in one DMA, apparently is isolated to the 622 as opposed to the 722, and is for OTA reception.

 

[daveray]

Have you tried to add channel and enter 31 to see if the 622 will get a signal if it will select done to save.

 

[dlsnyder]

I had a similar problem out here in Moreno Valley with KABC. Yes, I know KABC moved their digital channel to VHF channel 7. I had been getting a very good analog signal from them prior to the switch, but had some herringbone interference from nearby KVCR channel 24. When I tried rescanning after the switch, I found that channel 7 would take a long time to lock on my 622, although my Sony TV would lock it in just fine. I had to go up on my roof and turn my antenna just a bit off of the correct heading for Mt. Wilson so that I could reduce the interference from the nearby transmitter. There in Arcadia you are very close to Mt. Wilson, so this could be your problem too, especially if you are using an amplifier. Try turning your antenna a bit off of the correct heading, or perhaps try an attenuator. It seems counter-intuitive but it could help. Even with my antenna turned about 10 degrees off of the correct heading I still get a signal in the high-90's to 100 on all of the LA UHF channels, and 70 to 75 on the VHF channels. On top of that, I am using a RS UHF antenna and VHF/UHF amp. Not too shabby for being about 65 miles away from Mt. Wilson.

 

[denisincalif]

Have you tried to add channel and enter 31 to see if the 622 will get a signal if it will select done to save.

Yes, I have tried that. The display shows signal strength 0 and virtual channel number 0.

 

[denisincalif]

I had a similar problem out here in Moreno Valley with KABC. Yes, I know KABC moved their digital channel to VHF channel 7. I had been getting a very good analog signal from them prior to the switch, but had some herringbone interference from nearby KVCR channel 24. When I tried rescanning after the switch, I found that channel 7 would take a long time to lock on my 622, although my Sony TV would lock it in just fine. I had to go up on my roof and turn my antenna just a bit off of the correct heading for Mt. Wilson so that I could reduce the interference from the nearby transmitter. There in Arcadia you are very close to Mt. Wilson, so this could be your problem too, especially if you are using an amplifier. Try turning your antenna a bit off of the correct heading, or perhaps try an attenuator. It seems counter-intuitive but it could help. Even with my antenna turned about 10 degrees off of the correct heading I still get a signal in the high-90's to 100 on all of the LA UHF channels, and 70 to 75 on the VHF channels. On top of that, I am using a RS UHF antenna and VHF/UHF amp. Not too shabby for being about 65 miles away from Mt. Wilson.

That is one more thing to try. I do have some amplification on my antenna signal, which I can dial down. But I doubt that I have that problem. I am so close to the mountains that I can't see the broadcast towers on Mt. Wilson and Mt. Harvard because of a foreground ridge. So, except for KNBC and KCET, my signals are very weak.

 

[denisincalif]

I heard back from KTLA

Yesterday I e-mailed the KTLA engineering department about my problem. They responded this morning. The response doesn't promise anything, and they don't (at present) have any theories. But the fact that they responded at all is encouraging. I have e-mailed KTLA twice previously on unrelated issues and never heard a word back.

They did say some interesting things. They have not changed their PSIP recently, at least to their knowledge. They say that their "PSIP comes from New York". That is strange. Apparently they don't directly control their own PSIP information. They also say that they have tested their signal with a variety of tuners, new and old, and have not encountered any problems except with Vizio TV's. They are working on the Vizio problem. They have not actually tested a Mitsubishi or a VIP622.

I will re-post if any new information becomes available.

 

[sgip2000]

Have you tried the antenna from the Samsung on the 622 or the Mitsubishi?

It could be that they changed from UHF to VHF or vice versa and that your rooftop antenna is no longer able to pull the signal in.

 

[sam_gordon]

I'm not familiar with your location, but "too much signal" can cause a reception problem. For testing sake, dial down (or unplug) your amp, run your scan and see what you get.

 

[denisincalif]

Have you tried the antenna from the Samsung on the 622 or the Mitsubishi?

It could be that they changed from UHF to VHF or vice versa and that your rooftop antenna is no longer able to pull the signal in.

My rooftop antenna is VHF/UHF. And KTLA did not change. Their digital signal has been on channel 31 (UHF) ever since they started broadcasting digital. After the transition they stayed there.

 

[denisincalif]

I'm not familiar with your location, but "too much signal" can cause a reception problem. For testing sake, dial down (or unplug) your amp, run your scan and see what you get.

I definitely plan to do that, but I probably won't get to it until the weekend or early next week. But I would be a little surprised if too much signal is my problem. I am so close to the mountains that a foreground ridge blocks my view of the broadcast towers. If my house were a few blocks farther south then too much signal could well be the culprit.