DTT signal strenght

Racha78

Hi Guys,
Can somebody tell me if this is normal ?



I would have thought that with 6% signal you wouldn't have dreamed of having a chance of watching anything, never mind having a 98 % signal quality and grand picture with no pixelation at all !!! Only issues are when the freesat box is on at the same time but only on certain channels...
My TV is LG42pj350 by the way ...

Macy0161

I was experimenting with a cheap (and old) contract aerial, at head height a couple of weeks ago. Signal Strength 15-16% and I was getting similar quality levels to yourself. I was surprised at that, never mind at 6% strength, but isn't that one of the major selling points of DTT?

STB

Racha78 wrote: »

Hi Guys,
Can somebody tell me if this is normal ?

I would have thought that with 6% signal you wouldn't have dreamed of having a chance of watching anything, never mind having a 98 % signal quality and grand picture with no pixelation at all !!! Only issues are when the freesat box is on at the same time but only on certain channels...
My TV is LG42pj350 by the way ...

Thats DTT you either get it or you dont and its either pixelated/blocky or its stable.

6% though wow with 98% Quality. I mean its stable at 6%!

I like the LG NIT display. Very informative.

Where are you ? Kippure transmitter? (frequency ?)

What kind of aerial are you using ? Is it powered ?

How have got the satellite and aerial combined in any way ?

Racha78

STB wrote: »

Thats DTT you either get it or you dont and its either pixelated/blocky or its stable.

6% though wow with 98% Quality. I mean its stable at 6%!

I like the LG NIT display. Very informative.

Where are you ? Kippure transmitter? (frequency ?)

What kind of aerial are you using ? Is it powered ?

How have got the satellite and aerial combined in any way ?

Aerial I am using is Maxview AHG48W 48 element (no amp) and its in the attic . I bougt it ages ago for analogue... Tv has built in Freeview and aerial goes directly in the back of Tv and satellite in HDMI port ...
I'm in Lusk North Co. Dublin so I presume its Tree Rock Im picking up !?

ethernet

Pretty similar here.

Macy0161

Just on signal strength - what type of level do people reckon would be required for a stable signal/ maintain quality? Would 15-17% be enough for Irish DTT over a relatively short distance?

STB

Racha78 wrote: »

Aerial I am using is Maxview AHG48W 48 element (no amp) and its in the attic . I bougt it ages ago for analogue... Tv has built in Freeview and aerial goes directly in the back of Tv and satellite in HDMI port ...
I'm in Lusk North Co. Dublin so I presume its Tree Rock Im picking up !?

That UHF aerial should be pulling in a lot more than 6%.

Have you tried moving the direction of the aerial slightly to improve the signal strength? Ultimately a little booster would improve the strength. No kinks in cable etc ?

If its stable and your happy with it, its up to yourself of course. Me I'd be trying to get the highest strength.

Macy0161 wrote: »

Just on signal strength - what type of level do people reckon would be required for a stable signal/ maintain quality? Would 15-17% be enough for Irish DTT over a relatively short distance?

Its hard to gauge. Different types of equipment have different metering. I have a Humax - the strength is 61%, the CTech 5000C+ is 92%. On a Technomate its 90%. They just dont fit DB meters as standard! Of course that doesnt even bring in the sensitivity of tuners.

In the past anything below 40% strength is where I experienced pixelation. Quality is obviously very important but its fluctuation normally goes hand in hand with Signal Strength. That 6% and stable is startling! False readings would be the first to spring to mind

watty

Signal strength is irrelevent. You could have low level due to long feed cable or small aerial.

The quality is what matters.

You could have a 90% signal and breaking up picture and low quality due to co-channel interference, other interference or an amplifier that is poor quality or too much gain (signal distortion).

I'd not worry about signal level at all unless the quality is less than 75%

Macy0161

STB wrote: »

Its hard to gauge. Different types of equipment have different metering. I have a Humax - the strength is 61%, the CTech 5000C+ is 92%. On a Technomate its 90%. They just dont fit DB meters as standard! Of course that doesnt even bring in the sensitivity of tuners.

In the past anything below 40% strength is where I experienced pixelation. Quality is obviously very important but its fluctuation normally goes hand in hand with Signal Strength. That 6% and stable is startling! False readings would be the first to spring to mind

Thanks. It's actually for the inlaws - I picked up one of the sagem picnics for £15 while I got myself one, and have the contract knocking around.

They currently pick up Mount Leinster for tv3/ tg4, but I think the channel 45 issue will raise it's head so I'm looking for a cheap as chips temp solution pre official launch, without effecting their existing service. It'll be at chimney height, so I'm hoping that'll bring up the strength a bit too.

Post launch I'll do the proper job towards Kippure that the "professional" they had in should've done!

watty

The Sagem picnics will be rubbish after launch as they will not do RTE2 HD lite. There will be no RTE2 SD during HD, nearly 100% certain.

reaper180

well folks
newbie here,was looking around anyone know where i can get a uhf signal meter,i have seen a dual satellite and uhf meter but already have a sat dish so only need the meter to get dtt signal, thanks

glineli

watty wrote: »

The Sagem picnics will be rubbish after launch as they will not do RTE2 HD lite. There will be no RTE2 SD during HD, nearly 100% certain.

Do you expect an RTE HD service to start in October?

Macy0161

watty wrote: »

The Sagem picnics will be rubbish after launch as they will not do RTE2 HD lite. There will be no RTE2 SD during HD, nearly 100% certain.

I'm aware this may be the case - I've had them a while though for the trials (not a recent purchase). It was both the aerial and STB that I'll look at upgrading at launch for them, if necessary. Get them into DTT quality first and then look at getting them to spend some money

Also, assuming that RTE kids won't be HD, they'll do for the kids room telly, so it won't be a total waste, even if it is simulcast.

watty

glineli wrote: »

Do you expect an RTE HD service to start in October?

RTE have stated RTE2 will be part time HD (some sport to start with). In my mind a 31st Oct. start is Nov. 2010!

There will be more HD content when the 2nd Mux starts late 2011 early 2012. Unlike UK there is unlikely to be simulcast or separate HD program channel. It will simply be HD for HD content.

Probably.

glineli

My DTT channels pixelate when my 2 sky boxes are on. It causes the bit rate to go to 7/8, but when one is on it only goes to 4/5.

This is based on a samsung tv.

Any ideas how to cut this out?

12 element

I'd say your sky box is outputting its rf2 on the same channels as DTT is being broadcast. What Sky box do you have?

glineli

12 element wrote: »

I'd say your sky box is outputting its rf2 on the same channels as DTT is being broadcast. What Sky box do you have?

I have a thomson hd and a pace sky+. they rf out on 25 and 50 and dtt is on 48.

watty

50 is too close. The Modulator on any VHS, Setbox etc is simple AM. It takes up two channels. There is actually a signal on 49 also.

You need a spacing of one channel at least. Also the Sky Modulators are a bit noisy.

Try ch 55 and 62

or 21 and 28

glineli

watty wrote: »

50 is too close. The Modulator on any VHS, Setbox etc is simple AM. It takes up two channels. There is actually a signal on 49 also.

You need a spacing of one channel at least. Also the Sky Modulators are a bit noisy.

Try ch 55 and 62

or 21 and 28

Tried 21 and 28 and it works perfectly. Nice one, thanks

Racha78

Just to ad to this thread information that some people might find useful Didnt bother looking into this for a while as I had no problems with the picture. Replaced my old aerial wall socket the other day with Screened one out of curiosity and signal strength instantly jumped from 6 to 46 %. There you go lads, well worth the investment

watty

Most aerial sockets are modernised copies of 1950s VHF band I sockets (42 .. 68MHz) . They are rubbish for Band III (175 ... 275MHz) and terrible for UHF (470 .. 870MHz) and hideous for Satellite IF (900 .. 2100MHz).

lucernarian

I'd say sub-par for Band 3, not so much rubbish. And UHF is a pretty big band, those sockets haven't had massive effect at Group A frequencies in my testing but Ch 66 and 68 (TV3 and TG4 in Clermont Carn) were perceptively degraded just by having a socket like that inserted between TV and aerial.

watty

yes, but do you normally use N-types, BNC, SMA and have test gear? I've different measurement scale

lucernarian

I don't have to work with BNC or SMA connectors, not at home anyway. But real world conditions are more relevant to forums like this than lab-type tests, even if those are more reproducible.

To be fair, the Belling Lees could indeed be crap but as this is the Terrestrial forum, I added my two cents on VHF TV and FM.

watty

F-connectors are superior.

The Belling Lee wall plates and most F-Connector wall plates are hugely inferior to the actual cheap "belling-lee" plugs.

If there were Belling-lee wall plates as good as the Belling-lee plugs but I have not seen them. The Wall plates are only good (barely) to Band II VHF.

Nowadays if I have to use a wall plate I use a deep box so coax is not kinked and crimp F-Connector on the coax. The wall plate then has either a F-connector barrel joiner on it (hence one part is always longer on those) or the plate is drilled so the TV & SAT sockets of F-connector 900MHz Sat/TV diplexer stick through and internal cable with crimp connector screws on common. I fit two coax/four sockets on a plate over a deep cooker switch box using that scheme. I also have Right angle F-Connector junctions / extenders to fit cable on sharp turns without kink.