Mux 2 Launched / Saorview Rescan Required

Peter Rhea

White Heart Loon wrote: »

I'm noticing big differences in signal between the two Muxes on Cairns Hill, Truskmore and Castlebar, mux1 is stronger. Were the new transmitters fixed at half mast?

What are you measuring with? What would you call a 'big difference'?

I would like to think they spec'd the main transmitting aerials & feeders etc. to handle anything Saorview is likely to throw at them into the foreseeable future.

timmy4u2 wrote: »

. . . Many more have now stated that their RTE1 signal has deteriorated of late so there must be a common denominator

Some people's RTE1 deteriorated when it moved to a different frequency. Different frequencies propagate differently. Typical TV aerial gain isn't 'flat' across the band. A poor setup would have no margin to deal with these effects.

White Heart Loon

Peter Rhea wrote: »

What are you measuring with? What would you call a 'big difference'?

I am an installer and have a Horizon terrestrial meter. Sometimes as much as 6db

Peter Rhea

And you haven't seen any where mux 2 is stronger?

White Heart Loon

Peter Rhea wrote: »

And you haven't seen any where mux 2 is stronger?

Not so far, most of my work is off Truskmore but I've seen the same trend off Cairns Hill and Castlebar. I'll document it next time with exact readings

Peter Rhea

I'd say at some stage, you will come across one where mux 2 is stronger.

timmy4u2

Peter Rhea wrote: »

What are you measuring with? What would you call a 'big difference'?

I would like to think they spec'd the main transmitting aerials & feeders etc. to handle anything Saorview is likely to throw at them into the foreseeable future.



Some people's RTE1 deteriorated when it moved to a different frequency. Different frequencies propagate differently. Typical TV aerial gain isn't 'flat' across the band. A poor setup would have no margin to deal with these effects.

His reception on all channels were excellent up to the date and occurence in question so it must have been set up correctly.

Peter Rhea

timmy4u2 wrote: »

His reception on all channels were excellent up to the date and occurence in question so it must have been set up correctly.

The amount of times that or something similar has been posted in this thread . . .

Digital signals only need a slight drop for a signal that can appear 'excellent' on the TV, to go to nothing.

I take it you installed this aerial yourself? Why not just accept that the cause of the problem was something random, that may or may not have rectified itself without your going back to 'move it a few degrees'?

timmy4u2

Peter Rhea wrote: »

The amount of times that or something similar has been posted in this thread . . .

Digital signals only need a slight drop for a signal that can appear 'excellent' on the TV, to go to nothing.

I take it you installed this aerial yourself? Why not just accept that the cause of the problem was something random, that may or may not have rectified itself without your going back to 'move it a few degrees'?

You can take it that I did not. I had absolutely nothing to do with the installation of the aerial.
I cannot accept that it was something random.
(1) It coincided with HD on RTE.
(2) It worked without fault on very strong signals until that day.
(3) All the other channels on Mux 1 continued to work with great signal strength and quality.
(4)RTE 1 came back to full strength as I moved the aerial and now mux 1 and mux 2 are on excellent strength.
(5) many others, including posters on this thread, have similar experience of RTE1 failing.

timmy4u2

timmy4u2 wrote: »

You can take it that I did not. I had absolutely nothing to do with the installation of the aerial.
I cannot accept that it was something random.
(1) It coincided with HD on RTE.
(2) It worked without fault on very strong signals until that day.
(3) All the other channels on Mux 1 continued to work with great signal strength and quality.
(4)RTE 1 came back to full strength as I moved the aerial and now mux 1 and mux 2 are on excellent strength.
(5) many others, including posters on this thread, have similar experience of RTE1 failing.

It doesn't make sense though. What could RTE/2RN do that would produce a problem that requires the aerial to be moved? And why would they do such a thing in any case?

Peter Rhea

timmy4u2 wrote: »

I had absolutely nothing to do with the installation of the aerial.
I cannot accept that it was something random.
(1) It coincided with HD on RTE.
(2) It worked without fault on very strong signals until that day.
(3) All the other channels on Mux 1 continued to work with great signal strength and quality.
(4)RTE 1 came back to full strength as I moved the aerial and now mux 1 and mux 2 are on excellent strength.

With what are you measuring this strength & quality? The display on the TV?

That could be showing 100% for a signal that's only just good enough to give glitch-free viewing.

timmy4u2

Karsini wrote: »

It doesn't make sense though. What could RTE/2RN do that would produce a problem that requires the aerial to be moved? And why would they do such a thing in any case?

As I said I do not know, all I know is all the other mux1 channels were strong and remain strong, as was RTE1; on the day RTE1 went belly up, mux 1 remained strong. Turned aerial and RTE1 and Mux1 stations are all strong.Many have experienced a fall off on RTE1 only.
There has to be some external reason

Peter Rhea

timmy4u2 wrote: »

Many have experienced a fall off on RTE1 only.
There has to be some external reason

The reason is the change in frequency & the inability of their crappy aerial setups to handle it.

Your particular glitch just happened to coincide with the launch of RTE1 HD.

timmy4u2

Peter Rhea wrote: »

With what are you measuring this strength & quality? The display on the TV?

That could be showing 100% for a signal that's only just good enough to give glitch-free viewing.

I checked the signal display on the TV. Cross referenced them then used a signal finder as no business shouting down to a semi deaf person.

The Cush

A few weeks ago I finally took down my Mullaghanish VHF aerial and masthead amp, while I was up there I stuck a meter on the UHF aerial and both muxes were coming in at the same signal strength (approx. 61 dBuV) and BER.

A few years ago RTÉ were in at an Oireachtas Committee discussion on DTT and IIRC the issue of further muxes was discussed. It was mentioned during the discussion that coverage may not be identical for all frequencies from the same transmitter.

I assume in these cases installing a higher gain aerial will be required or mounting an aerial outside. I use a DMX10A hi-gain aerial in a reasonably difficult reception area mounted on a gable-end with the aerial at ridge level.

timmy4u2

The Cush wrote: »

A few weeks ago I finally took down my Mullaghanish VHF aerial and masthead amp, while I was up there I stuck a meter on the UHF aerial and both muxes were coming in at the same signal strength (approx. 61 dBuV) and BER.

A few years ago RTÉ were in at an Oireachtas Committee discussion on DTT and IIRC the issue of further muxes was discussed. It was mentioned during the discussion that coverage may not be identical for all frequencies from the same transmitter.

I assume in these cases installing a higher gain aerial will be required or mounting an aerial outside. I use a DMX10A hi-gain aerial in a reasonably difficult reception area mounted on a gable-end with the aerial at ridge level.

That makes some sense as to what has happened.
Hi-gain aerials and amps brings me back quite a few years but then again Wales is far away and it was illegal to retransmit at the time.

Ronnie Raygun

Jpmarn wrote: »

I have advised my sister to contact a tv expert to adjust her aerial

That's a good move.

timmy4u2 wrote: »

That makes some sense as to what has happened.

How does it make any more sense than the other explanations you got?

timmy4u2

Ronnie Raygun wrote: »

That's a good move.



How does it make any more sense than the other explanations you got?

Because I assess all the information and it makes sense.

Ronnie Raygun

timmy4u2 wrote: »

Because I assess all the information and it makes sense.

The only part relevant to you is the bit about different frequencies maybe having slightly differing coverage. Wasn't that already mentioned a whole pile of times?

timmy4u2

Ronnie Raygun wrote: »

The only part relevant to you is the bit about different frequencies maybe having slightly differing coverage. Wasn't that already mentioned a whole pile of times?

No really. Most were saying nothing happened. It was just a coincidence etc etc.
One thing is sure I am not going up into his attic to turn the aerial back just because it shouldn't work.

Peter Rhea

timmy4u2 wrote: »

Ronnie Raygun wrote: »

The only part relevant to you is the bit about different frequencies maybe having slightly differing coverage. Wasn't that already mentioned a whole pile of times?

No really. Most were saying nothing happened. It was just a coincidence etc etc.
One thing is sure I am not going up into his attic to turn the aerial back just because it shouldn't work.

What are you on about now? Are you saying the fact that mux 2 is carried in a different UHF channel to mux 1 has not been mentioned?

By 'nothing happened', I mean on the day that RTE1 officially went HD. The change to mux 2 had taken place before that.

Maybe your relative had been watching the original mux 1 version (no. 11 in the EPG) up until then?

Ronnie Raygun

The Cush wrote: »

... while I was up there I stuck a meter on the UHF aerial and both muxes were coming in at the same signal strength (approx. 61 dBuV) and BER ... I use a DMX10A hi-gain aerial in a reasonably difficult reception area mounted on a gable-end with the aerial at ridge level.

61 dBμV at ridge level doesn't make me think "difficult"!

timmy4u2

Peter Rhea wrote: »

What are you on about now? Are you saying the fact that mux 2 is carried in a different UHF channel to mux 1 has not been mentioned?

By 'nothing happened', I mean on the day that RTE1 officially went HD. The change to mux 2 had taken place before that.

Maybe your relative had been watching the original mux 1 version (no. 11 in the EPG) up until then?

I dont give a da#n about mux 1or mux 2 and I have no desire to argue about them. I got his tv working on all channels by moving the aerial, and no, he was not watching on c11 and it happened on that Monday that I mentioned several posts ago when they did some change with HD.

Peter Rhea

timmy4u2 wrote: »

I dont give a da#n about mux 1or mux 2 and I have no desire to argue about them. I got his tv working on all channels by moving the aerial, and no, he was not watching on c11 and it happened on that Monday that I mentioned several posts ago when they did some change with HD.

Well, here goes again: the 'change' to HD had no effect whatsoever on the robustness of the transmitted DVB-T multiplex (mux) & by extension, the ability of any receiving system to function as before, all else being equal.

You are welcome to persist in your belief but, I don't like to see dumb ideas gaining traction with others who read these threads.

timmy4u2

Peter Rhea wrote: »

Well, here goes again: the 'change' to HD had no effect whatsoever on the robustness of the transmitted DVB-T multiplex (mux) & by extension, the ability of any receiving system to function as before, all else being equal.

You are welcome to persist in your belief but, I don't like to see dumb ideas gaining traction with others who read these threads.

Well no body came up with a viable solution and many others experienced the same problem.
I solved it by moving the aerial and that was better than all the negative suggestions and observations.

The Cush

Ronnie Raygun wrote: »

61 dBμV at ridge level doesn't make me think "difficult"!

Difficult in analogue days that required a hi-gain aerial and masthead amp.

No problems now considering Mullaghanish is transmitting 200kW ERP DTT, the equivalent of 1,000kW analogue. Analogue was transmitted at 220kW VHF/375kW UHF.

MarkK

There have been plenty of people who have reported a better Mux 2 signal than Mux 1

mcd121 wrote: »

only rte1,rte1+1 and rte junior working on my saorview
Hey lads
Went home for xmas and when i returned to my house in galway net2 tv3 and tg4 not on my saorview all of a sudden? Tried retuning and it says 8 channels found but its just black screen.
Any ideas? Nothing has changed. Thanks in advance

eliwallach wrote: »

Hi, sorry if this was asked before, but:
Set up Soarview (through a Walker box) and easily set up all 7 of the home channels. however, I recently seem to have lost RTE2, TV3, TG4 and 3e (service not running message) while RTE1, RTE Jnr and RTE +1 are fine. Any suggestions?

Peter Rhea

timmy4u2 wrote: »

Well no body came up with a viable solution and many others experienced the same problem.
I solved it by moving the aerial and that was better than all the negative suggestions and observations.

There was no reason for anyone to think that a small adjustment of the aerial would do any good, over & above any other solution. It happened to work in your case, this time.

TAFKAlawhec

Lets go over a few pointers again...

Even when frequencies are fairly close (e.g. 3-4 channels on the UHF band), the chances of them having differing signal and quality levels are perfectly possible even in "good" reception areas. Though in those places that should not be a cause for concern. Fringe reception is more hazardous.

So why the difference?

* Transmission aerial - the two Saorview multiplexes are transmitted with the same maximum ERP from each site. However there can be differences what the ERP is in certain directions from the transmission aerials - even transmitter aerials that are set up for omni-directional transmission will have a few nulls due to the phasing of the transmission panels that from a view looking from the bottom of the mast or tower, looking straight up from the ground will look somewhat like a four-leaf clover for example. The horizontal beam of the aerial is also phased. In most cases for the bigger transmitter sites at least, this is aimed so that the peak power strength is aimed at the near-horizon, with the idea of wasting little going over the horizon into space.
However when two transmissions are fed into the same aerial at the same power but at different frequencies, the radiated transmission will show some slightly different radiation patterns due to the dimensions of the aerials and the phasing. This for example in the four-leaf clover pattern mentioned above contribute to the peak direction of the transmission in the aerial stack shift by a few degrees at each leaf-end, or change the value of the "null" between two stacks etc. The horizontal beam tilt pattern can also be slightly different.

* Receiving aerials don't behave the same at different frequencies. As most UHF TV aerials in Ireland are either the Yagi or Grid/Bowtie type, these have characteristics which see the gain change at different frequencies as well as directional characteristics. Even grouped Yagi aerials that are designed to work only over a narrow band of frequencies can have significant differences (3db or even more) between the frequencies they're intended to cover.

* Path between transmission & receiving aerials. Various affects can affect different frequencies especially if the two sets of aerials don't have line of sight with each other, and to an extent where the Fresnel Zone isn't completely cleared. How the waves of different frequencies clear over obstacles like hills & buildings, how they are scattered in the atmosphere, how they reflect off nearby objects etc. come into play. If an aerial is not mounted outdoors above the roof line i.e. in an attic or in a room, this can matter even more. Weather can also have occasional effects, though for Saorview this should not be as readily seen compared to satellite where rain-fade is more pronounced.

* Interference - this could be specific to just one of the frequencies that you're trying to receive. This interference can be from a transmission normally not received e.g. tropospheric enhancement that is often seen on hot summer days and still foggy winter mornings. Or it can be from something man-made.

I remember in the analogue days it was common enough for different TV channels to show different picture quality even with a "good" set up. For example, where I lived Channel 4 from Brougher Mountain always seemed to be that little weaker than the other three channels. Carin Hill was noted for TG4, for some reason, getting better reception at a slightly different direction compared to its other three channels. As an extreme example, receiving analogue TV from Truskmore required a VHF Band III aerial for RTÉ1 & RTÉ2 - the difference in bearing between this aerial and a UHF aerial for TV3 & TG4 from the same transmission site was about 10 degrees.

If a UHF aerial was installed for Saorview prior to Mux 2 formally launching, it's perhaps stretching it a bit to blame an installer for having a "poor" aerial installation because you can't measure something that isn't there. It would have been better prior to 24/10/12 when there was also 2, 3 or 4 analogue UHF services that could also be measured against each other for the best "compromise" and fine-tuning of the installation that would provide ruggedness for future Saorview transmissions especially if they were formerly on old analogue frequencies.

To sum it up, there's no conspiracy by RTÉ or 2RN, there's unlikely to be deliberate malpractice regarding coverage, it's just that some people that receive Saorview services might need a little fine tuning on their installation to receive two frequencies compared to just one before.

timmy4u2

TAFKAlawhec wrote: »

Lets go over a few pointers again...

Even when frequencies are fairly close (e.g. 3-4 channels on the UHF band), the chances of them having differing signal and quality levels are perfectly possible even in "good" reception areas. Though in those places that should not be a cause for concern. Fringe reception is more hazardous.

So why the difference?

* Transmission aerial - the two Saorview multiplexes are transmitted with the same maximum ERP from each site. However there can be differences what the ERP is in certain directions from the transmission aerials - even transmitter aerials that are set up for omni-directional transmission will have a few nulls due to the phasing of the transmission panels that from a view parallel to the ground will look somewhat like a four-leaf clover for example. The horizontal beam of the aerial is also phased. In most cases for the bigger transmitter sites at least, this is aimed so that the peak power strength is aimed at the near-horizon, with the idea of wasting little going over the horizon into space.
However when two transmissions are fed into the same aerial at the same power but at different frequencies, the radiated transmission will show some slightly different radiation patterns due to the dimensions of the aerials and the phasing. This for example in the four-leaf clover pattern mentioned above contribute to the peak direction of the transmission in the aerial stack shift by a few degrees at each leaf-end, or change the value of the "null" between two stacks etc. The horizontal beam tilt pattern can also be slightly different.

* Receiving aerials don't behave the same at different frequencies. As most UHF TV aerials in Ireland are either the Yagi or Grid/Bowtie type, these have characteristics which see the gain change at different frequencies as well as directional characteristics. Even grouped Yagi aerials that are designed to work only over a narrow band of frequencies can have significant differences (3db or even more) between the frequencies they're intended to cover.

* Path between transmission & receiving aerials. Various affects can affect different frequencies especially if the two sets of aerials don't have line of sight with each other, and to an extent where the Fresnel Zone isn't completely cleared. How the waves of different frequencies clear over obstacles like hills & buildings, how they are scattered in the atmosphere, how they reflect off nearby objects etc. come into play. If an aerial is not mounted outdoors above the roof line i.e. in an attic or in a room, this can matter even more. Weather can also have occasional effects, though for Saorview this should not be as readily seen compared to satellite where rain-fade is more pronounced.

* Interference - this could be specific to just one of the frequencies that you're trying to receive. This interference can be from a transmission normally not received e.g. tropospheric enhancement that is often seen on hot summer days and still foggy winter mornings. Or it can be from something man-made.

I remember in the analogue days it was common enough for different TV channels to show different picture quality even with a "good" set up. For example, where I lived Channel 4 from Brougher Mountain always seemed to be that little weaker than the other three channels. Carin Hill was noted for TG4, for some reason, getting better reception at a slightly different direction compared to its other three channels. As an extreme example, receiving analogue TV from Truskmore required a VHF Band III aerial for RTÉ1 & RTÉ2 - the difference in bearing between this aerial and a UHF aerial for TV3 & TG4 from the same transmission site was about 10 degrees.

If a UHF aerial was installed for Saorview prior to Mux 2 formally launching, it's perhaps stretching it a bit to blame an installer for having a "poor" aerial installation because you can't measure something that isn't there. It would have been better prior to 24/10/12 when there was also 2, 3 or 4 analogue UHF services that could also be measured against each other for the best "compromise" and fine-tuning of the installation that would provide ruggedness for future Saorview transmissions especially if they were formerly on old analogue frequencies.

To sum it up, there's no conspiracy by RTÉ or 2RN, there's unlikely to be deliberate malpractice regarding coverage, it's just that some people that receive Saorview services might need a little fine tuning on their installation to receive two frequencies compared to just one before.

Excellent informed post.

Any of my forays into receiving channels was purely on a hobby basis when most of the South of Ireland had only RTE1.
It was a nice weekend pastime and we got loads of exercise also by climbing hill after hill.

As I posted earlier even then we realised the pattern and we made up receiving antennae by grouping four Wisi aerials in what could be called a clover pattern.
It worked well most of the time.

Ronnie Raygun

timmy4u2 wrote: »

... As I posted earlier even then we realised the pattern and we made up receiving antennae by grouping four Wisi aerials in what could be called a clover pattern.

The "clover" pattern mentioned by Lawhec, would have no bearing at all on how you would configure your receiving array.

I presume your "clover" receiving aerial pattern was 2 x 2 aerials arranged as a vertical square or rectangle, like the receiving array on the relay transmitter here or maybe it was a cross shape?