Antenna signal

[Ruurd]

Hello forum members,

How much high frequent antenna signal must I have for a good digital picture?
My signal status is mostly “signal strength 60-80” “signal quality 85-90”
Sometimes I get blurred or square blocks on my T.V.
Could I amplify my antenna signal up to, say +20 db, without the risk to introduce
intermodulation in the T.V.tuner?
I know it’s a technical question but I hope some one can help me out.
My T.V. is a 32PFL3507H type.Last update 2.15 version

Regards,

Ruurd

Holland

[chrisham]

Are you sure that the artefacts you are observing are not compression related rather than signal quality related?

From my experience, what you are describing are compression macro-blocks. With digital reception, the video stream usually completely collapses if reception is not sufficient, rather than showing isolated image artefacts.

Do you usually see the problem in fast-changing scenes (explosions, rapid camera movement, ...)? If yes, this also points towards compression problems, since fast changes in the picture require bigger band-width.

Which medium are you recieving? DVB-T (over-the-air digital), or cable/satellite?

[Ruurd]

Hello Chrisham,

Thanks for the repost on my post, I receive my T.V. programs through a cable connection.
What you say about band-with it could by an option, it look likes exactly what you say.
Some times when somebody moves his head then the picture is blurred.
Adjusting the band-with is no option I think, there are no settings on the T.V. to manage.
I have also a HD recorder Samsung SMT-C7140 which has no problem at all, with the same signal.
Increasing the signal strength could be a option?
Waiting you answer, send you my regards ,

Ruurd,

Holland

[chrisham]

Hi Ruurd,

if the problem is really compression-related, then there is nothing that can be done on the TV side, apart from trying to somehow mask the problem.

For that, some TVs have an option called something similar to 'MPEG artefact reduction'. If you can find an option like this in your TV's picture settings, try setting it to a higher level.

However, this does not 'fix' the problem, it only tries to mask it! Often, this leads to other problems, like 'soft' images - this is again not really fixable, since the feature (if available) only filters the image to make the artefacts less obvious.

The root of the problem is that MPEG uses lossy compression - in cases where the video - because of its dynamic content - 'wants' to use more bandwidth than the configuration of the compression on the source side is providing, the picture information is lost on the source side, and simply not available in the signal. No amount of filtering on the TV's side can bring this information back.

[Ruurd]

Hello Crisham,

Thanks for the tip about Mpeg artefactreduction.
There are two possibilities “off or on”
On my T.V. it was in a off state, I have just set it on now.
It is now a matter of time how my T.V. response on this setting.
Later I shell tell you what my experience is about my T.V.
So far so good.

Regard,

Ruurd

[Ruurd]

Hello Crisham,

This artifact setting helps me out most of the time.
And I have supply an antenna amplifier between my incoming cable.
This one which I can adjust at a good signal strength.
Most channels are now free of artifacts and square images.
Thank you for the tips and on my concerned is this topic closed.

My regards,

Ruurd

[chrisham]

Hi Ruurd,

thanks for getting back to us on this topic.

One question, out of curiosity: does the antenna amplifier make a difference in your case, or is the improvement mainly due to the suppression of MPEG artefacts via the picture setting?

Greetings,

-chrisham

[Ruurd]

Hello Chrisham,

One week I have used my TV without a antenna amplifier and then sometimes there are artefacts.
The suppression of MPEG artefacts was on.
Week two I have ad the antenna amplifier and then most of the disturbing was over.
Per example before the amp, signals are a 25 %, after adding a amp, signals are a 90%.
This value was readout from a HD recorder the SMT-C7140 from Samsung.
My TV and HD recorder are connected via a splitter so they becomes a same value of signal.
That was the story of my problems, I hope its clear to you.
Al the best Chrisham,

Regards, Ruurd.