Mux 2 Launched / Saorview Rescan Required

DeadSkin

peking97 wrote: »

FWIW that's a very similar antenna to the one I'm using mounted in the attic and I have it split to feed two TV's and signal is consistently strong with no retune issues. HTH.

Are you getting your signal from maghera too?

Peter Rhea

It's nothing to do with the design of the aerial. And no point comparing to other peoples' installations either. Their aerials aren't installed in your attic.

DeadSkin

Peter Rhea wrote: »

It's nothing to do with the design of the aerial. And no point comparing to other peoples' installations either. Their aerials aren't installed in your attic.

Are my options 1) either mount the aerial outside or 2) some form of amplification?

The Cush

DeadSkin wrote: »

Are my options 1) either mount the aerial outside or 2) some form of amplification?

The quickest and easiest option would be to stick a distribution amp in the attic and see how it goes.

DeadSkin

The Cush wrote: »

The quickest and easiest option would be to stick a distribution amp in the attic and see how it goes.

Does the amp have to be near the aerial or can I have the amp downstairs? I don't have power in the attic.

The Cush

DeadSkin wrote: »

Does the amp have to be near the aerial or can I have the amp downstairs? I don't have power in the attic.

As close to the aerial as possible to reduce further signal loss down the cable

A masthead amp with remote power supply is an option in that case, a liitle more expensive than a standard distribution amp.

http://www.satworld.ie/amps-and-diplexers/masthead-amp-sets.html

Have you tried moving the aerial a little to see if the signal improves?

peking97

DeadSkin wrote: »

Are you getting your signal from maghera too?

Yes I'm tuned to Maghera.

DeadSkin

The Cush wrote: »

As close to the aerial as possible to reduce further signal loss down the cable

A masthead amp with remote power supply is an option in that case, a liitle more expensive than a standard distribution amp.

http://www.satworld.ie/amps-and-diplexers/masthead-amp-sets.html

Have you tried moving the aerial a little to see if the signal improves?

No I haven't moved it yet hopefully over the weekend. Thanks for the link at least I have that option.

Paully D

Peter Rhea wrote: »

Have to be a spoilsport here but, you haven't sorted anything out if the channel you want is 'jittery'.

There's a possibility you aren't tuned to the right transmitter.

Hi Peter, how do I tune to the correct transmitter? Thanks.

DeadSkin

Paully D wrote: »

Hi Peter, how do I tune to the correct transmitter? Thanks.

The Cush supplied a saorview link a few posts back where you enter your location and it tells you what transmitter you should use. Get the freq/channel information for the mux and perform a manual scan with those details.

The Cush

Paully D wrote: »

how do I tune to the correct transmitter?

Find your recommended transmitter here - http://www.saorview.ie/what-is-saorview/make-the-switch/coverage-map/

Where are you located approx.?
Are you using an indoor or outdoor aerial?

TAFKAlawhec

No real problems here with Carin Hill Saorview Mux 2 on E44.

In terms of different signal strengths between the two multiplexes from the same site - this is most certainly not unusual. If you're in a good signal area for the transmitter served and the signal strength & quality meters on your receiver show good but slight differences e.g. Mux 1 is Strength 84% Quality 94% and Mux 2 is Strength 78% Quality 98%, then you don't really have much to worry about. Where this can be more noticeable is where the received signals are more marginal. Various factors come into play including (a) the radiation patterns from the transmitting aerial for each frequency will be at least very slightly different , (b) the performance of the receiving aerial at each frequency - there can be slight but noticeable differences between 1-2db strength even between 3-4 channel allocations with yagi and grid aerials, less so for log periodics, (c) Co-channel interference factors, though international and national co-ordination should keep this minimised at least to the point of one multiplex possibly being substantially more affected than the other, and (d) objects between your receiving aerial and the transmitter when either the path is not line-of-sight or where the receiving aerial is not mounted outdoors i.e. attic or set-top aerial.

In the case of (d), the different frequencies may take slightly different paths to your receiving aerial because of the likes of hills or trees blocking line-of-sight reception causing the radio waves to bounce or refract at different angles. In the case of aerials indoors, how the radio waves enter indoors is affected. For example with an attic aerial unless it is looking at the transmitter dead-on (the line of tiles form a 90 degree line bisecting the path between the transmitter and receiver aerial) the incidence angle of the radio waves going through the tiles will be different for each frequency. For set-top aerials (and to some extent attic aerial), radio waves bouncing around in a room off walls or metal objects will often mean that as well as the "direct" signal, if it's being used, it will pick up reflected signals also. If these reflected signals as a sum add to to being strong enough and also well out-of-phase of the direct signal, it will reduce the signal to your receiver and this can happen even in strong signal areas.

Pre-DSO up here in the north, with the six low-powered Freeview multiplexes is was quite often noticeable (even allowing for the difference in the 16QAM and 64QAM multiplexes) in many places where DTT reception was marginal that only some multiplexes would come on some aerials in even if (a) the multiplexes are in the same aerial group and (b) had the same ERP. For example, from Brougher Mountain with an attic aerial, Mux2 (UTV & CH4) on E34 came in fine, but MuxA (SDN) on E23 required the aerial to point slightly more to the left otherwise it wouldn't be well received. Move the aerial to improve the signal and quality of MuxA reception and not only did Mux2 reception suffer, all the other four multiplexes did too.

I think it was Peter Reah who pointed out that this could have been visibly seen in the analogue days where if they were all on UHF (e.g. Three Rock, Carin Hill, Clermont Carn etc.) that for many people the picture quality of all four channels varied to a greater or lesser extent. This is simply the digital equivalent of it.

There is another factor - (e) tidal fading. This only applies to those either in coastal areas or where there is a large body of water along the path between the transmitter and receiving aerial. Experience is dealing with tidal fading in the analogue days will still apply to Saorview & Freeview except that the effect now is more disruptive because of the digital cliff effect.

So where it was easy to align an aerial for one multiplex only, getting it set up right for two multiplexes in a small number of cases is a little trickier. You are almost certainly unlikely to be affected in a good signal aerial with a proper UHF aerial that is outdoors and mounted above at least the gutter line (provided the roof doesn't shield between you and the transmitter - in that case you're better off just sticking it in the attic!) and the path between your aerial and the transmitter is not massively blocked, and likely to be most problematic for those using indoor, set-top aerials.

On a related note, I've been comparing the picture quality of the new RTÉ One channel on Mux 2 in upscaled HD (1440x1080) to that of the RTÉ One channel on the NIMM from Brougher Mountain which is SD, but unlike SD Saorview video streams which are 544x576, the NIMM streams are 720x576. From my own observations it is tricky to find any significant difference in picture quality between the two - presumably the upscaled HD stream is being sourced with a 720x576 stream. Sometimes the upscaled HD stream is a little better, but you have to notice it very closely. It's certainly noticeable on the likes of on-screen graphics that RTÉ One on Saorview Mux2 is upscaled, but both that and the NIMM RTÉ One stream are still improvements on the original RTÉ One stream on Mux1 which suffered from softness due to a low horizontal resolution especially on 16:9 material.

DeadSkin

The Cush wrote: »

As close to the aerial as possible to reduce further signal loss down the cable

A masthead amp with remote power supply is an option in that case, a liitle more expensive than a standard distribution amp.

http://www.satworld.ie/amps-and-diplexers/masthead-amp-sets.html

Have you tried moving the aerial a little to see if the signal improves?

I moved the aerial to a more central location in the attic and I tuned the channels in perfectly for about ten minutes. Then it started to go all jumpy again. Think it's time to get one of those amplifiers you linked me to. Any recommendations on what type?

Peter Rhea

DeadSkin wrote: »

I tuned the channels in perfectly for about ten minutes. Then it started to go all jumpy again. Think it's time to get one of those amplifiers . . .

Is this just with 1 receiver connected directly to the aerial & no splits? Can you get a tv into the attic & hook it up to the aerial with a fairly short cable?

If you try this & still don't get stable reception, there is no point bothering with an amplifier.

Ronnie Raygun

TAFKAlawhec wrote: »

There is another factor - (e) tidal fading. This only applies to those either in coastal areas or where there is a large body of water along the path between the transmitter and receiving aerial. Experience is dealing with tidal fading in the analogue days will still apply to Saorview & Freeview except that the effect now is more disruptive because of the digital cliff effect.

More disruptive? Doesn't the multi-carrier scheme, frequency interleaving & FEC of COFDM make it far less susceptible to this kind of frequency-selective fading? Or is that only applicable where the frequencies affected are changing fairly quickly, as in mobile reception?

DeadSkin

Peter Rhea wrote: »

Is this just with 1 receiver connected directly to the aerial & no splits? Can you get a tv into the attic & hook it up to the aerial with a fairly short cable?

If you try this & still don't get stable reception, there is no point bothering with an amplifier.

I have the sat and terrestrial signals coming down one cable with one of those combiner/splitter dealies to one combo box receiver. No chance of getting the tv in the attic. If the amplifier is not an option is there anything else I can do. Seems to me this mux transition is going to disrupt a lot of people's setups.

The Cush

DeadSkin wrote: »

If the amplifier is not an option is there anything else I can do. Seems to me this mux transition is going to disrupt a lot of people's setups.

The one I mentioned initially, mounting the aerial outside. The setups that are being affected are those with problem aerial installation and/or non-approved receivers.

You can still go down the route of a masthead amp but if it doesn't prove successful you will have to consider moving the aerial outside.

The Cush

Ronnie Raygun wrote: »

More disruptive? Doesn't the multi-carrier scheme, frequency interleaving & FEC of COFDM make it far less susceptible to this kind of frequency-selective fading? Or is that only applicable where the frequencies affected are changing fairly quickly, as in mobile reception?

I remember this being a reported problem during ASO in Spain.

http://www.televes.com/sites/default/files/info_119_en.pdf - page 4

DeadSkin

The Cush wrote: »

The one I mentioned initially, mounting the aerial outside. The setups that are being affected are those with problem aerial installation and/or non-approved receivers.

You can still go down the route of a masthead amp but if it doesn't prove successful you will have to consider moving the aerial outside.

My tv is saorview approved and has the same issues trying to tune in mux2 off the aerial in the attic. Think it's time to dust off the drill and mount the aerial outside!

stereomatic

Quality of TV channels are 65% and Radio channels are 70% for both muxes despite not having a saorview approved TV (It's a Samsung but not a Samsung Smart TV) nor having the aerial (outside) directed northeast towards Mt. Leinster being in a valley and some tall buildings blocking reception however the aerial is pointed southeast to no-where with the reasonable reception has anybody got an idea why this might be happening?

All I can think is that it might be some sort of echo.

Peter Rhea

stereomatic wrote: »

Quality of TV channels are 65% and Radio channels are 70% for both muxes despite not having a saorview approved TV (It's a Samsung but not a Samsung Smart TV) nor having the aerial (outside) directed northeast towards Mt. Leinster being in a valley and some tall buildings blocking reception however the aerial is pointed southeast to no-where with the reasonable reception has anybody got an idea why this might be happening?

1) You should have the same quality on tv & radio & the tv not being Saorview approved would have no effect on quality.

2) Aerials aren't 100% directional & will pick up signals from the sides & behind, though these will be attenuated compared with the direction of maximum gain. Mt. Leinster is very powerful, though.

3) Are you sure you are picking up Mt. Leinster?

stereomatic

Channel 23 (490000kHz) and Channel 26 (514000kHz) all coming in
Located in County Wexford

Ronnie Raygun

The Cush wrote: »

I remember this being a reported problem during ASO in Spain.

http://www.televes.com/sites/default/files/info_119_en.pdf - page 4

It's mentioned in passing in that document as a factor that can contribute to fading. It seems the SFN is the major factor in this case.

AFAIA, the Med. has only a tiny tidal range anyway.

theoneeyedman

Don't know if this is the right place but here goes.
Did the rescan yesterday and rte1 is gone to hell...pic breaking up and is more like a set of stills than moving pictures. All other terrestrial channels are OK and old rte1 with the rescan instruction looks OK.
Recievng signal from cairn hill near Longford

WeHaveToGoBack

Maybe I'm missing something but are the Mux 2 channels being broadcast from the same transmitters as Mux 1, and even if they aren't why is the difference in quality so vast?

Peter Rhea

WeHaveToGoBack wrote: »

. . . are the Mux 2 channels being broadcast from the same transmitters as Mux 1, and even if they aren't why is the difference in quality so vast?

They are transmitted from the same sites, yes.

There is no quality difference in the transmissions. I wish people would stop posting this rubbish.

Peter Rhea

theoneeyedman wrote: »

Don't know if this is the right place . . .

Maybe have a bit of a read of the thread & see?

WeHaveToGoBack

Peter Rhea wrote: »

They are transmitted from the same sites, yes.

There is no quality difference in the transmissions. I wish people would stop posting this rubbish.

well why can I (and seemingly others too) receive the Mux1 channels fine yet Mux2 is barely receivable?

Peter Rhea

WeHaveToGoBack wrote: »

well why can I (and seemingly others too) receive the Mux1 channels fine yet Mux2 is barely receivable?

Because your receiving aerial setup is no good. More than likely you are barely receiving mux 1 too, but it's just far enough above the decoding threshold to appear trouble-free.

WeHaveToGoBack

Peter Rhea wrote: »

Because your receiving aerial setup is no good. More than likely you are barely receiving mux 1 too, but it's just far enough above the decoding threshold to appear trouble-free.

Quite possibly, but if Mux2 and Mux1 are being broadcast at the same strength from the same location or whatever, surely Mux2 should be receivable too then?