UHF Freeview - how to improve picture?

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457 posts

Ultimate Geek

#291756 21-Jan-2010 09:51

pukunui: I don't want to have to buy a bluray player but we'll see. Does running the UHF signal through my DVD player make a difference? I'm not sure it would since I can watch TV even if the DVD player is off. I think the reason I ran it through the DVD is so I could record shows on the VCR (yeah, old school, I know).

you should be fine. may pay to plug the aerial cable directly into your tv to rule out your dvd player degrading the signal though.

butlerboy

457 posts

Ultimate Geek

#291757 21-Jan-2010 09:52

freeview demo channel is 100

Jaxson

8042 posts

Uber Geek

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#291760 21-Jan-2010 09:58

Yeah honestly sounds like two different problems here. If you're trying to run a DVD player into a large digital TV via composite RCA you are just asking for problems. Get some component video leads, or spend that money and a little bit more on a DVD player that upscales out via hdmi.

Freeview TV is a different problem. If you are in a UHF reception area for terrestrial TV then this should look stunning by comparison to analog TV, especially on TV1, 2 and 3 during prime time. Make sure you are watching the digital tuners picture and not the analog version of the channels and make sure your aerial is aligned properly and fit for purpose (ie drop the VHF aerial if it's not needed any more and run a direct RG6 cable with f connections from UHF aerial to TV directly, no splitters initially).

pukunui

42 posts

Geek

#291765 21-Jan-2010 10:05

SBIDDLE: Thanks. I'll go out and get a component cable in a little while.

BUTLERBOY: I tried plugging the aerial directly into the TV last night and couldn't really see any difference. I don't need the VHF anymore, though, so I might see if the UHF aerial will reach the TV without needing an extension cord (which is basically all the "combiner" cable is acting as at the moment).

Also, I found the Freeview Demo Channel. That's what was playing on the TV in the store. It looks great on my screen. So did the Minuit music video TV3 just showed. So I guess maybe it's NOT a problem with the TV?

JAXSON: RG6 cable? What is that? Is it something that would go in between the UHF cable and the TV? I don't want to have to go messing with the aerial itself. I'm basically stuck with whatever cable is currently attached to the aerial and run through the wall of the house.

DanielCamp

4 posts

Wannabe Geek

#291769 21-Jan-2010 10:13

Hi there..

When you say you are using a combiner to put uhf and vhf into one cable.... Are you also using another one to split the uhf and vhf into their own signals..?
Combiners are extremely useful for bringing the two signals down from the roof, but putting the two signals into your tv will cause the 'ghosting' effect you described, as the two signals are both trying to show at once..
If you use another combiner or diplexer in reverse you can split the uhf and vhf signals, and then feed just the uhf into your tv..

No guarantees, but this could be the root of your issues..

pukunui

42 posts

Geek

#291771 21-Jan-2010 10:15

DANIEL: No, I'm not using a splitter. I've got the UHF and VHF cables going into the combiner and then the single combiner cable goes into the DVD player and then there's another cable that goes from the DVD player to the TV.

sbiddle

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Biddle Corp

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#291773 21-Jan-2010 10:25

DanielCamp: Hi there..

When you say you are using a combiner to put uhf and vhf into one cable.... Are you also using another one to split the uhf and vhf into their own signals..?
Combiners are extremely useful for bringing the two signals down from the roof, but putting the two signals into your tv will cause the 'ghosting' effect you described, as the two signals are both trying to show at once..
If you use another combiner or diplexer in reverse you can split the uhf and vhf signals, and then feed just the uhf into your tv..

No guarantees, but this could be the root of your issues..

You don't get ghosting with digital signals.

Signal issues will either cause a loss of picture entirely, or more commonly picture breakup which normally results in pixelisation.

This doesn't seem to be occuring so any changes to the aerial setup probably won't make any difference at all.

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

pukunui

42 posts

Geek

#291777 21-Jan-2010 10:32

Yeah, I never got ghosting on my old CRT analog TV even with the combiner. And my TV separates the digital channels and the analog channels, so I've just been sticking with the digital ones.

When I was talking about ghosting before, I might have used the wrong word. I'm talking more about artifacts. The kind you get when you take a 72dpi jpeg and increase the resolution to 300dpi. The computer has to insert data where there isn't any, so you get blurry spots that are called artifacts. I seem to be getting quite a bit of that at times on my TV.

Overall, though, things seem to be better than they were yesterday. Either I'm getting used to it or I have managed to improve things.

Now: I've just checked and my UHF cable cannot reach the TV on its own. I need an extension cord and at the moment the combiner's cord is acting as one. I've unplugged the VHF cable though since I don't actually need it.

I am planning on going out in a little while to the mall. I'll stop at JB Hi-Fi and see if they have what I need. If not, I'll go across the road to Dick Smiths. What I want to know is: Is there anything I should be getting aside from a component cable?

DanielCamp

4 posts

Wannabe Geek

#291778 21-Jan-2010 10:32

The two signals will still interfere with each other.. Even though the digital cliff prevents signal issues like ghosting etc, if the tv is not smart enough to split out the vhf component, it could be trying to display both inputs simultaneously. The uhf signal is slightly delayed which could cause a ghosting effect.
When you start mixing the two together, they don't always behave as a textbook says they should, and even as a starting point spending $8 on another combiner to get a purely uhf signal into your hd tv is a good way to go..

pukunui

42 posts

Geek

#291783 21-Jan-2010 10:38

OK well I've unplugged the VHF, but as I said, I still need some sort of extension cord. Is just using the combiner's cord that I've got, sans VHF, OK? Or is there something else I should use?

DanielCamp

4 posts

Wannabe Geek

#291787 21-Jan-2010 10:42

Can't see any reason why that won't work..

pukunui

42 posts

Geek

#291789 21-Jan-2010 10:43

OK so given my setup, is there anything aside from the component cable that I should be getting while I'm out today?

dolsen

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#291814 21-Jan-2010 11:31

DanielCamp: The two signals will still interfere with each other.. Even though the digital cliff prevents signal issues like ghosting etc, if the tv is not smart enough to split out the vhf component, it could be trying to display both inputs simultaneously. The uhf signal is slightly delayed which could cause a ghosting effect.

What?
If you are tuned to the digital, freeview signal that is broadcast of UHF in HD, you should have a great picture. The VHF analogue signal will not interfere with the uhf brodcast to cause ghosting or any other effect. The only difference is that the vhf signal (or the act of combining it in) could reduce the signal strength or corrupt the signal enough to prevent decoding. This would result in pixilation and or pauses / missed frames. You would not see ghosting.

robjg63

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#291822 21-Jan-2010 11:54

I wonder if in fact the problem is that your picture is breaking up - rather than 'ghosting' as you initially described it. Your signal strength and quality sounded ok though.

In basic terms - provided your aerial is plugged in to the TV and you have managed to tune in the Freeview HD channels (which you seem to have done), the picture will either be as 'perfect' as it was broadcast (whether that was standard def or hi def depends on the TV station) or if the signal/picture quality is not good enough it will start pixelating noticably. Freeview HD is pretty much an all or nothing thing - it being a digital medium. Its not like the old analogue picture in that respect.

If the signal/picture quality isnt good enough - or is going up and down (which can happen with bad aerial/wiring/interference) then you need to solve that. The only other thing that could be causing 'ghosting' might be some of those fancy pants image sharpening/image improvement features in the TV - they normally dont mess the picture up too much - but are easily turned off under the TVs menu so you can check.

Otherwise - go back to the shop and look at their demo model - If you think yours is worse then maybe the TV is faulty???

Nothing is impossible for the man who doesn't have to do it himself - A. H. Weiler

pukunui

42 posts

Geek

#291836 21-Jan-2010 12:17

ROBJG63: Ghosting wasn't the right term. Artifacts is the right term. Like a low-res jpg that's blown up too large.

But as I said before, I tried the Freeview HD Demo Channel and it looked great. So obviously if I'm getting a not-so-great picture it's not my TV but the program itself.

So now it's mostly trying to figure out why Men In Black looked so bad on the DVD player when the newer, fully CGI Barbie looked fine ...

I bought a component cable at Dick Smith ($25-$50 compared to $80-$120 at JB Hi-Fi) but it's too short. Gotta go back and get the longer one. Sigh ...

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