TV1 & 2 pixelating, all others fine

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E3xtc

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Topic # 82561 2-May-2011 08:55

Howdee.

Just wondering if anyone has any thoughts on an issue I am having:

We have a situation where TV1 and TV2 are suffering form bad reception whereas when jumping to other channels the others all work fine.
When looking at the signal information the bit errors jump through the roof on the TV1/2 whereas the others just seem to truck along with no errors whatsoever.

Same is happening on both TV's in the house (using the same signal feed). Its a terrestrial feed from Waitakere Ranges.

I would have thought if one channel is getting a dodgy signal then they all would be suffering.

I rescanned the channel listings last night - which made no difference at all - was stabbing in the dark for ideas.

Any ideas as to what in the world is going on?

Cheers
Troy

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Reply # 464371 2-May-2011 09:03

Given the strong winds and rain last night I would guess it's weather related.
I used to get it all the time when it rained and was caused by water getting into the Antenna's junction box and then the coax feeder. Problem solved with new antenna and coax which is all weather proof. Another souce of problems can be wet trees in the vicinity of the antenna..

E3xtc

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Reply # 464373 2-May-2011 09:10

That is the thing - this has been an issue for a while now, it is only recently that it occurred to me that it is only happening on TV1 and 2...so this isn't specifically associated with the bad weather this weekend.

Jaxson

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Reply # 464393 2-May-2011 10:16

E3xtc: I would have thought if one channel is getting a dodgy signal then they all would be suffering.

The channels come on different (one of three) frequencies. It's not entirely impossible that your aerial is better on some frequencies than others. A thorough check of the aerial condition and then cabling/splitters and end terminations etc would be the way to proceed.

E3xtc

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Reply # 464405 2-May-2011 10:50

Thanks for that - can anyone recommend anyone in the West Auckland/Titirangi area that might be best suited to assist with this? I previously had Teletech come out; and am almost 100% sure that things are worse after their attempts :(

sbiddle

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Reply # 464449 2-May-2011 12:22

Freeview has 3 MUX's - TV1 and TV2 are on the same TVNZ MUX. If you're experiencing issues with TV1 or TV2 that are signal related odds are you'll see the same issues on the other channels on the TVNZ MUX that includes TVNZ7 and U.

E3xtc

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Reply # 464450 2-May-2011 12:24

So at the end of the day, does that mean that this is still likely to be a signal issue; one that my only option is to try and improve the signal we are getting (ie as mentioned above - cables, connectors, aerials, etc)

E3xtc

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Reply # 467068 9-May-2011 12:01

Great to see that yesterday and all through the weekend TVNZ's signal was crap as usual, whereas TV3 was solid and strong.

Connections all "look okay"...Is there anything I can do (as a layman) to make this better or am I at the mercey of the powers that be at TVNZ? :(
Or maybe just need to throw some more money at someone who knows what they are doing?

Jaxson

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Reply # 467072 9-May-2011 12:08

If your aerial is not the best and receives some signals stronger than others that doesn't mean the signal is at fault. Without investigating further you don't know that the signals are being sent at different power levels.

What is your aerial setup:

-Is it new, is the cabling good, are the terminations at either end ok etc?

- Are you in a good strong reception area and are you using an amplifier etc?

You are feeding two TV's - How is the cable being split etc?

E3xtc

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Reply # 467090 9-May-2011 12:50

The aerial isn't new - it's about 10 years old - but we did put a new one up on the roof and it made no difference (so subsequently took it down).
Same goes for the cabling in terms of age - it all looks okay....the cables look in good condition, the termination points seem to be in good nick.

Reception wise we are at the bottom of a gulley, so not super by any stretch...but certainly strong enough to consistently get solid 95/100 reading on signal strength on the TV3 signal...TVNZ jumps up to that point but fluctuates between 60-85 on average with bit errors coming through and killing the picture.

We are running a powered amplifier

We are running 2 TV's. The splitter is in the roof. So it goes from aerial through roof cavity to splitter, then approx 7m run to one TV and then 20m run to the other TV. Signal issues are encountered on both TV's; neither are any better than the other.

Any thoughts are greatly received :)

Jaxson: If your aerial is not the best and receives some signals stronger than others that doesn't mean the signal is at fault. Without investigating further you don't know that the signals are being sent at different power levels.

What is your aerial setup:

-Is it new, is the cabling good, are the terminations at either end ok etc?

- Are you in a good strong reception area and are you using an amplifier etc?

You are feeding two TV's - How is the cable being split etc?

mthand

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Reply # 467112 9-May-2011 13:38

From Waiatarua, the 3 frequencies are 538MHz, 570MHz, and 666MHz. Make sure that all of your frequencies are set to these.

Although as sbiddle says, if TVNZ7 and U are fine, it won't be a signal issue though

Pixelation on the only 720p channels sounds like it could be an issue with the graphics in the set(s). Are the two TV's set the same model (with inbuilt tuner), bought at the same time?

Jaxson

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Reply # 467143 9-May-2011 15:08

They are all 1080i now so that's not it sorry.

Very good point about the frequencies. Make sure you're tuned to the strongest signal possible for those channels. In locations where there are potentially multiple transmitters within range, the TV can sometimes try to get those channels from a weaker source. Try this, even if you have to manually tune the TV's.

B1GGLZ

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Reply # 467177 9-May-2011 16:21

We are running a powered amplifier

Presumably your power amp is at the masthead?
Is the DC power supply being passed thru the splitter to the amp?
Not all splitters pass DC one one or both connectors.
Only real test is to try new antenna and coax direct to one TV with no splitter. Or get a field strength test done.
You haven't said if TV7 and U are also pixellating. They are on the same MUX.

mthand

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Reply # 467201 9-May-2011 17:36

OMG tvnz have gone to 1080i? Next think they'll be going (back) to AC3 ;-)

E3xtc

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Reply # 467378 10-May-2011 07:48

Thanks everyone for the feedback - I will try to manually configure (check) the frequencies that are currently being used.

To answer a few of the questions:

TV's are different models.
Pretty sure TVNZ7 was all over the show on the weekend also - I gave up and just settled with TV3 in the end (which was solid as a rock)
The amp is just one that is plugged into the outlet/wall plate

So if the frequency comes up with nothing, then I am thinking that I will have to get someone around to run cable directly to the set (bypassing the splitter etc) and get some proper tests done :)

Muchas Gracias fellas!

trig42

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Reply # 467409 10-May-2011 09:23

Have you tried it without the amplifier plugged in? Sometimes they can make it worse (they amplify everything, good and bad). Also, see if you can just bypas the splitter (join the in and out cables together with a joiner) and see if that makes a difference - with and without the amplifier.

I'm certain that if you are getting good signal on the other 2 muxes then The TVNZ one can be sorted.

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