Welsh digital switch over-Irish reception questions answered

aerial man

Peter Rhea wrote: »

What about the Freeview HD mux on ch50? Does the 5052 diplexer kill it?

I wouldn't recommend this kind of setup to anyone with coverage from Mt. Leinster; just wait for the Saorview channel change at switchover which will have the added bonus of much easier combining with the Preseli signal.

Yes, There was HD on it, only in good weather as this hasnt the same power as 43 etc i am editing this as i was checking today and a triax 5052 WILL allow ch 50 to work, there is a 5153, however this walks into a problem with 52 from forth!!

This was posted today by mrdtv2010 - http://www.boards.ie/vbulletin/showthread.php?t=2056516278 which is a very useful post! Thanks again

I totally agree with Peter about waiting until the ASO in October for most people however we installed this in july 2011 and at the time there was no movement on ch45 on mt leinster, this was the best working solution at the time. It wont cost much to rearrange it. I found the photo today and just said id post it up here.

This set up is perfect for anyone near Wexford town, hoping to use forth mountain combined with preseli

aerial man

FRIENDO wrote: »

Good News.

I picked up a Saorview Vision VST 8010 STB in Powercity.
I normally get signal strength around 40% - 50% on the LG tv or Ferguson Combo for Forth and when combined with Freeview I would loose Forth.

With the Vision STB Forth was coming in at 90%-100%, so I combined the signal's with a white splitter at the back of the Vision stb.
Slight change to the Saorview signal possible 1% and Freeview coming in loud and clear.

I wonder is it something to do with new software in the Saorview Vision STB ?

Its holding a couple of days perfect, will monitor reception to see how it holds.

Im not sure, although i think it uses the Saorview as priority eg stores RTE1 on one etc. Ive noticed on older TVs running MPEG4 that rte wouldnt always be one one, that BBC1 is stored on one, as Preseli was stronger than Gorey at that location, then at other times, at low pressure (weaker BBC signal), RTE1 would get the hotspot!!

On most of all new saorview approved TV's, Saorview always starts off at 1.

Peter Rhea

aerial man wrote: »

This set up is perfect for anyone near Wexford town, hoping to use forth mountain combined with preseli

Yep, for anyone who has to use Forth, it's a no-brainer.

newleaf

After two weeks of perfection on Freeview and even Freeview HD the signal from Arfon seems to have become very erratic and mostly disappeared! Anyone else finding this? Is it dodgy weather on Welsh side or something over Irish sea?

joceadaigh

newleaf wrote: »

After two weeks of perfection on Freeview and even Freeview HD the signal from Arfon seems to have become very erratic and mostly disappeared! Anyone else finding this? Is it dodgy weather on Welsh side or something over Irish sea?

I'm afraid I can't really help with that, I've been having lots of trouble with arfon and now blame some big trees about 500meters aways for blocking my signal.

But today I've come up with a question and it may or may not be related to your problem.

How does frequency offsets interfere with neighbouring mux frequencies? For example Arfom BBCA is Ch41+ and and Presely SDN is on Ch42-, will these co-channel.

Today I've noticed something I haven't seen before, with grid aerial pointed at Three Rock and the others (high gain towards arfon) aerials disconnected the Freeview HD tuner has recognised signals at Ch42, 43, 45, 46 and 49, (not 50 though). Hasn't made a sound on Ch41, 44, or 47. How are weather conditions for signals travelling today, average, good or bad.

blackius

joceadaigh wrote: »

I'm afraid I can't really help with that, I've been having lots of trouble with arfon and now blame some big trees about 500meters aways for blocking my signal.

But today I've come up with a question and it may or may not be related to your problem.

How does frequency offsets interfere with neighbouring mux frequencies? For example Arfom BBCA is Ch41+ and and Presely SDN is on Ch42-, will these co-channel.

Today I've noticed something I haven't seen before, with grid aerial pointed at Three Rock and the others (high gain towards arfon) aerials disconnected the Freeview HD tuner has recognised signals at Ch42, 43, 45, 46 and 49, (not 50 though). Hasn't made a sound on Ch41, 44, or 47. How are weather conditions for signals travelling today, average, good or bad.

Presely does not follow the usual rules which is why it became such a head ache in the south east for those confined to mt leinsters ch 45.

Preseli signal goes ballistic ahead of an advancing weather front.
I do not know the science of this.

As obviously our prevailing weather conditions mean a lot of advancing weather fronts,then this happens a lot.

As for arfon 41 versus presely 42,polarity is different so no issues.
I've been able to pick up both actually during lift conditions despite being pointed to preseli .

@newleaf,that shouldn't be happening.You might need to check to see if nothings blown up there.

newleaf

Thanks Blackius. My Panasonic TV says signal strength about 80% but signal quality nil! Can anyone diagnose from that? Don't know how reliably the TV measures quality/strength but it very high for both up to a few days ago when it nose dived to nothing! Came back briefly, then BYEE! If no improvement in a day or two more will investigate gear more thoroughly. Do masthead amps ever blow?

Ronnie Raygun

joceadaigh wrote: »

How does frequency offsets interfere with neighbouring mux frequencies? For example Arfom BBCA is Ch41+ and and Presely SDN is on Ch42-, will these co-channel.

Adjacent channel interference (ACI) is the potential problem but only if one of the signals is at a considerably higher level than the other.

The active part of the offset DVB-T mux is still contained within the 8 mHz bandwidth. DVB-T2 muxes using extended carrier mode do actually invade the adjacent channel when offset, though.

reslfj

Ronnie Raygun wrote: »

Adjacent channel interference (ACI) is the potential problem but only if one of the signals is at a considerably higher level than the other.

The active part of the offset DVB-T mux is still contained within the 8 mHz bandwidth. DVB-T2 muxes using extended carrier mode do actually invade the adjacent channel when offset, though.

Ofcom asked if there was any know problems with DVB-T2 extended and frequency offset and got no answers.

This graph is taken from the DVB-T2 standard, but the DVB-T spectrum is very much the same.



The 8k mode will be about half way between the red and green lines.

Lars

Gerry Wicklow

newleaf wrote: »

Thanks Blackius. My Panasonic TV says signal strength about 80% but signal quality nil! Can anyone diagnose from that? Don't know how reliably the TV measures quality/strength but it very high for both up to a few days ago when it nose dived to nothing! Came back briefly, then BYEE! If no improvement in a day or two more will investigate gear more thoroughly. Do masthead amps ever blow?

My LG tells me ch45 (co-channel Mt L and Presely) is about 78% sig but 0% quality. Depending on weather, I get Presely at 79-80% Sig, otherwise zip. it's that fine.

FRIENDO

aerial man wrote: »

Here is an aerial set up we've been testing for the last while near Kilmuckridge, Co Wexford. It has been working perfectly on ch 52 for Saorview from forth mt, also Ch 42, 43, 46 and 49 working very reliably.
Ch 45 does not work due to mt Leinster causing interference but this was expected. The TV used was a 32" Samsung



It has a 5052 diplexer with a low gain mast head amp ( to guarantee a consistent signal )

Hi aerial man,

What aerial are you using for Forth Mth,

I imagine its a group B for Freeview.

Is it wideband or group you are using for Forth ?

Thank you.

blackius

newleaf wrote: »

Thanks Blackius. My Panasonic TV says signal strength about 80% but signal quality nil! Can anyone diagnose from that? Don't know how reliably the TV measures quality/strength but it very high for both up to a few days ago when it nose dived to nothing! Came back briefly, then BYEE! If no improvement in a day or two more will investigate gear more thoroughly. Do masthead amps ever blow?

yes they blow alright.
Though your problem sounds like red ruth co channel.
It also sounds like an allignment issue.

When myself and mylie were doing [well 99.9% mylie:D] an arfon instalation on the wexford road in arklow,we discovered that all the aerials on the road were pointed a couple of degree's off.
Goodness knows what their reception was like.
It was a case of lazy aerial installers pointing the aerial the same as the other houses and when the first one was wrong,they all were.

Theres where a good meter is handy.It showed up that mistake and by the way that arfon is blasting in as usual
signal strength today 97% quality 100 on a samsung.

newleaf

Thanks again Blackius, narrowing down the issue I think. Mylie did great job for me recently so alignment not a problem. I gather you have excellent Arfon today on Wexford Rd Arklow while I have nothing from Arfon on Dublin Rd! So, if problem not Arfon itself, or alignment, does that leave masthead amp the culprit? Could Redruth co channel interference affect me but not you? Next few days should tell I suppose.

joceadaigh

blackius wrote: »

yes they blow alright.
Though your problem sounds like red ruth co channel.
It also sounds like an allignment issue.

When myself and mylie were doing [well 99.9% mylie:D] an arfon instalation on the wexford road in arklow,.

newleaf wrote: »

I gather you have excellent Arfon today on Wexford Rd Arklow while I have nothing from Arfon on Dublin Rd!

Just wondering, why would people in Arklow use Arfon over Preseli? Is there something in the way?
And Blackius, do u mind me asking where abouts are you located getting Preseli?

Ronnie Raygun

blackius wrote: »

When myself and mylie were doing [well 99.9% mylie:D] an arfon instalation on the wexford road in arklow,we discovered that all the aerials on the road were pointed a couple of degree's off.
Goodness knows what their reception was like.
It was a case of lazy aerial installers pointing the aerial the same as the other houses and when the first one was wrong,they all were.

Theres where a good meter is handy.It showed up that mistake ...

All it showed is that the particular aerial it was connected to had been well aligned. You're not dealing with line of sight conditions here; hook your meter up to one of the other nearby aerials & it won't necessarily end up pointing exactly the same way as the 1st one.

blackius

I'm in arklow.
Parts of the town use preseli and other parts use arfon.
Arklow rock,over near roadstone blocks preseli for much of the Dublin road area.
It also weakens it on the wexford road.
preseli on the coolgreaney road in arklow comes in better than it does in wales I think.
Presely analogue used suffer co channel from cairn hill so some parts of the town also to avoid that were on arfon.

@newleaf arfon is blasting in today as usual so it's an equipment error you have.
I'd also think your aerial may be slightly mis alligned as it's the same people that did most aerials in the town.
Best aerial guy I know would be mylie redmond down in Gorey.

edit,if it was mylie did yours then it's not misalligned.
I'd suggest ringing him.

blackius

Ronnie Raygun wrote: »

All it showed is that the particular aerial it was connected to had been well aligned. You're not dealing with line of sight conditions here; hook your meter up to one of the other nearby aerials & it won't necessarily end up pointing exactly the same way as the 1st one.

actually ask mylie.
The aerials we are talking about are next door and the mis allignment couldn't be more obvious [unless theres a secret other welsh tx which of course there isn't]

aerial man

FRIENDO wrote: »

Hi aerial man,

What aerial are you using for Forth Mth,

I imagine its a group B for Freeview.

Is it wideband or group you are using for Forth ?

Thank you.

Hi Friendo,

We used a QR10 Wideband aerial, as it is quite close to C/D anyway. The amp if memory serves me correct was a small gain amp that we got just to try out, i think a W 12db gain , it was used to just guarantee Saorview as it had a borderline strength.
This particular job was an experiment, combining Forth with Preseli, having Mt leinster also quite strong in the background.
The Saorview never failed, while preseli has about 95% consistency on the main muxs. the tv didnt have dvb-2 so no HD but ch 50 worked on the meter.

newleaf wrote: »

Thanks again Blackius, narrowing down the issue I think. Mylie did great job for me recently so alignment not a problem. I gather you have excellent Arfon today on Wexford Rd Arklow while I have nothing from Arfon on Dublin Rd! So, if problem not Arfon itself, or alignment, does that leave masthead amp the culprit? Could Redruth co channel interference affect me but not you? Next few days should tell I suppose.

I think the Co channel is a problem there as strength is showing high on the tv's signal meter, so possibly counting out the amp going faulty, also with high pressure, signal is high at the moment. I wonder where the interference is coming from. Has anyone else lost Arfon in the last few days?

I suppose you'll just have to wait to see does the signal come back. Let me know how it goes after tomorrow

Ronnie Raygun

newleaf wrote: »

I gather you have excellent Arfon today on Wexford Rd Arklow while I have nothing from Arfon on Dublin Rd! So, if problem not Arfon itself, or alignment, does that leave masthead amp the culprit?

How long have you had this aerial installation & when did it start giving trouble?

Are you close to the Arklow transmitter? A strong signal from there could cause overload problems, regardless of the channel in use, although you would have expected this to be spotted by the installer or have given trouble right from the start.

blackius

Ronnie Raygun wrote: »

How long have you had this aerial installation & when did it start giving trouble?

Are you close to the Arklow transmitter? A strong signal from there could cause overload problems, regardless of the channel in use, although you would have expected this to be spotted by the installer or have given trouble right from the start.

The wexford road instalation is about 100 metres from the arklow tx and no problems whereas the Dublin road would be about a kilometer away or more.
Though I understand thats the direction arklow fires full power towards but as you say why would it suddenly become a problem.

@ newleaf in my opinion,this has to be something simple enough.I would contact Mylie.

Heres the wexford road aerial by the way which is about 98% arfon reliable.
The grid is for mt leinster, saorview from which was unviewable during preseli lifts.Kippure vhf.
They have full signal from arklow now though through the back of it.

Ronnie Raygun

Ronnie Raygun wrote: »

Are you close to the Arklow transmitter? A strong signal from there could cause overload problems, regardless of the channel in use ...

I suppose the question to ask newleaf is, what is your Saorview reception like?

newleaf

@Ronnie Raygun: My Saorview is excellent. On Dublin side of Arklow. Was getting it fine on old Analogue aerial! But new setup has it coming in fine on UHF aerial.

Mylie coming to the rescue tomorrow! Fingers crossed on getting Arfon back. Was even getting reasonably reliable Freeview HD on Icecrypt box until signal died. Good box, Irish channels in the 800's not a major problem. I only use it to get digital into my Hard Disk recorder as TV does Freeview and Saorview fine.

newleaf

Problem solved. The masthead amp had stopped working. Thanks to Mylie and son for sorting me out. And thanks to all of you on this thread that were helpful. Come back Arfon all is forgiven. Freeview and Freeview HD coming in crystal clear again. G'night.

GatsbyDub

I've been reading this entire thread for the past week and find it very interesting.

I'm surprised that the last post to it was in January of 2012.

Anyway, I was wondering...given the information supplied on here about the Blaen Plwyth Transmissions being unavailable in Arklow...but available in a part of Bray, if I would receive it in Blainroe....3 miles south of Wicklow town.

I did receive great analogue reception from Arfon on a vertical arial with a masthead amp. Of course, sometimes it suffered from 'tidal fading' at night.

I'm right on the coast and have unobstucted view to Arfon Tx......but it is a Freeviw Light Tx and I'd like to get the other channels.

Any advice would be very much appreciated.

Sam Russell

GatsbyDub wrote: »

I've been reading this entire thread for the past week and find it very interesting.

I'm surprised that the last post to it was in January of 2012.

Anyway, I was wondering...given the information supplied on here about the Blaen Plwyth Transmissions being unavailable in Arklow...but available in a part of Bray, if I would receive it in Blainroe....3 miles south of Wicklow town.

I did receive great analogue reception from Arfon on a vertical arial with a masthead amp. Of course, sometimes it suffered from 'tidal fading' at night.

I'm right on the coast and have unobstucted view to Arfon Tx......but it is a Freeviw Light Tx and I'd like to get the other channels.

Any advice would be very much appreciated.

I got Blaen Phwyth in Bray but it was hit and miss. Do not waste your time. You are too far south.

whitebriar

It might be no harm trying for Preseli there,it's available in Rathdrum and at the tap and jack whites.

GatsbyDub

Thank you, Sam Russell and Whitebriar!

I'll try the Preseli Tx...it'll mean a change of polarity, won't it?

Used pick it up on analogue during a good summer.....even though the polarity was different....it came in with wide 'band lines' on the screen.

A pity Arfon is Freeview Light given its Tx height, but I suppose they have to look after their own.

Anyway, thanks again for the heads up on this.

GatsbyDub.

Pat X

GatsbyDub wrote: »

I've been reading this entire thread ....

Christ! 2 pages of barstool engineering and I had enough.

Skull Murphy

Deleted User wrote: »

.... Blaen in the 60's and 70's was widely used with perfect reception for HTV on the East coast on VHF.

Old thread & all, but I can't resist correcting mistakes.

Blaenplwyth was a BBC band I site & didn't transmit HTV on VHF. That would have been Arfon.

whitebriar

Skull Murphy wrote: »

Old thread & all, but I can't resist correcting mistakes.

Blaenplwyth was a BBC band I site & didn't transmit HTV on VHF. That would have been Arfon.

Correct,Blaenplwf was used for BBC,Arfon for Htv.
Most people had the one vhf aerial for both,commonly referred to as the welsh aerial.

GatsbyDub

whitebriar wrote: »

Correct,Blaenplwf was used for BBC,Arfon for Htv.
Most people had the one vhf aerial for both,commonly referred to as the welsh aerial.

In parts of Dublin in the late 60's and in the 70's a lot of people received BBC from NI and HTV Wales, but as far as I remember they were 2 different types of arial. The NI one was very wide in size and the HTV, although a lot smaller, seemed to have a horizontal polarisation.

Skull Murphy

For 405 line tv, most of the BBC stations (including Divis) used VHF band I. The frequencies here (about 41 - 68 mhz) meant long wavelengths & correspondingly long aerial elements (about 10 ft. on the lowest channel).

IBA stations were in band III (about 175 - 220 mhz) & the wavelengths here allowed shorter aerial elements: the same band was used by RTE at some sites up until ASO.

Combination band I/III, such as the "Welsh aerial" mentioned above were available & could be used where the wanted stations were in the same general direction (some even allowed for different polarisation in band I & III).

watty

625 RTE1 was on VHF Band I here till 1999. Some Combo Band I /BandIII aerials still up.

aerial man

watty wrote: »

625 RTE1 was on VHF Band I here till 1999. Some Combo Band I /BandIII aerials still up.

Where was that transmitted from Watty?

The Cush

aerial man wrote: »

Where was that transmitted from Watty?

Maghera VHF Band I Ch.B (H) for then single channel RTE, changed to VHF Band III Ch.E (V) RTÉ1 in 1999. RTÉ2 on VHF Ch.H (V).

Originally planned to use Ch.A but was replanned to avoid interference with BBC Ch.1 transmissions.

01 March, 1962

My Department has also consulted the other Administrations concerned regarding a change from Channel A to Channel B in the frequency allocated to Gort Station under the Stockholm Agreement and if this change is approved the station should not interfere with reception from the B.B.C. transmissions on Channel 1. An announcement in the matter will be made in the near future.

http://www.oireachtas-debates.gov.ie/D/0193/D.0193.196203010085.html

RTÉ 1 was on Channel E since 1992 so there was a 7 year simulcast period.

I remembered being quite surprised when I picked up a weak RTÉ 1 on Band I when I moved to north Kerry in the mid 90s. I knew nothing about the network then as I was only a child, but it was the first time I had seen anything on Band I that wasn't a cable service.

Ronnie Raygun

GatsbyDub wrote: »

... Anyway, I was wondering...given the information supplied on here about the Blaen Plwyth Transmissions being unavailable in Arklow...but available in a part of Bray, if I would receive it in Blainroe....3 miles south of Wicklow town.

Blaenplwyf doesn't radiate full power towards Ireland. It may come as a surprise to some of the posters in this thread, but this is mainly due to the fact that not many Welsh people live in the Irish Sea, not solely down to RTE asking them to "null" or "shield" the transmission ...

The 15 degree restriction mentioned will be in the agreed templet for the radiation pattern, along with other possible restrictions & I would think that as long as the pattern is kept within these limits, it can be any shape that will suit the service area & will be heavily influenced by the sensibly realisable aerial configurations available. They certainly won't be cutting out 15 degree notches, just to spite people in Arklow.

marclt

Given the coastal location, it makes sense not to transmit out to sea. There literally is maybe less than 1km between Blaenplwyf and the sea to the west.