DTT & ATT in Galway

Freeman

I need some advice on whether I am on the right track with this. I want to setup DTT as well as ATT. I don't have an Aerial yet just Freesat but I need the Irish Channels.

I'm in Galway, near GMIT. From what I can tell I would use Maghera and would need a Green Group Aerial (UHF C/D). What I don't get is how do I receive VHF bands (RTE1/2) on a UHF aerial? Do I need to buy a VHF aerial as well? I would be using both Analogue and the DTT service.

What's the best way to distribute Freesat? I have a single Uni LNB and a single HD Receiver on a motorized dish. I have 3 TVs. Do I need a Receiver for each TV? Do I need to change the LNB?

Sponge Bob

Freeman wrote: »

I'm in Galway, near GMIT. From what I can tell I would use Maghera and would need a Green Group Aerial (UHF C/D). What I don't get is how do I receive VHF bands (RTE1/2) on a UHF aerial?

Answer is you don't receive VHF on a high UHF group aerial but on a wideband aerial . You should also consider a Group A aerial pointing at Tonabrocky to the west which is a DTT only transmitter.

An amplified UHF C/D aerial will probably work fine for VHF too because you have a good signal there but it could be a tad grungy.

watty

Freeman wrote: »

I need some advice on whether I am on the right track with this. I want to setup DTT as well as ATT. I don't have an Aerial yet just Freesat but I need the Irish Channels.

I'm in Galway, near GMIT. From what I can tell I would use Maghera and would need a Green Group Aerial (UHF C/D). What I don't get is how do I receive VHF bands (RTE1/2) on a UHF aerial? Do I need to buy a VHF aerial as well? I would be using both Analogue and the DTT service.

What's the best way to distribute Freesat? I have a single Uni LNB and a single HD Receiver on a motorized dish. I have 3 TVs. Do I need a Receiver for each TV? Do I need to change the LNB?

Satellite needs a receiver for each tv, or a TV with satellite receiver built in.
Depends how many sat receivers you want.
Some suitable reading that explains everything
http://www.techtir.ie/saor
http://www.techtir.ie/articles/howto
http://www.saortv.info
You may not need VHF as it's getting turned off in 2012 along with rest of analogue. Our new Living Room TV has no analogue tuned on it. The other TVs still use Analogue, but late 2011 to mid 2012 we will feed them with satellite or Terrestrial setboxes via SCART.

Digifriendly

Freeman wrote: »

I need some advice on whether I am on the right track with this. I want to setup DTT as well as ATT. I don't have an Aerial yet just Freesat but I need the Irish Channels.

I'm in Galway, near GMIT. From what I can tell I would use Maghera and would need a Green Group Aerial (UHF C/D). What I don't get is how do I receive VHF bands (RTE1/2) on a UHF aerial? Do I need to buy a VHF aerial as well? I would be using both Analogue and the DTT service.

Out of interest why do you need to use analogue as well as DTT when ROI DTT has all the channels that are transmitted in analogue as well as a few more?

Freeman

@Spongebob: Can you explain a little more as to why I would use Tonabruckey instead of Maghera and are you saying I would need a Wideband VHF and a Group A UHF to get the best quality but might get away with a UHF C/D aerial with an amplifier of some sort?

@watty: I think I need a Quad LNB and some combo receivers. Thanks for the links.

@Digifriendly: It's all about the money. I have 3 TVs, 1 Sat receiver, and can really only afford 1 combo receiver right now. That will give satellite to 2 tv's, analog to 2 tvs and dtt to 1.

Sponge Bob

Freeman wrote: »

@Spongebob: Can you explain a little more as to why I would use Tonabruckey instead of Maghera and are you saying I would need a Wideband VHF and a Group A UHF to get the best quality but might get away with a UHF C/D aerial with an amplifier of some sort?

No, a wideband for Maghera but a group A for Tonabrocky which is DTT only.

Maghera signal is good so a UHF C/D could pick up an analogue VHF signal too but may need amplifying in that case. No analogue by the end of next year anyway.

Galway

There is NO point using 3 aerials and two transmitters when analogue and DTT are required. A VHF band 3 aerial for RTÉs 1 and 2 analogue, vertically mounted and a group c/d UHF aerial for TV3 and TG4 analogue and all DTT channels, horizontally mounted should be adequate at your location. If you dont use a VHF band 3 aerial you will get crap RTÉ 1 & 2 pictures, especially as it is in a different band and uses a different polarity from TV3 and TG4.

Anywhere near GMIT has a clear view into Co. Clare and the mountain where the Maghera transmitter is located. Mount the UHF aerial horizontally at the top of the pole and the VHF one below it, leaving spacing of about a metre. As you need to connect more than one TV set, then you can install a distribution amplifier in the attic with separate VHF and UHF inputs, so you can connect the two aerial downleads into this and so you will not need an external VHF-UHF diplexer. You should not need a outdoor masthead amplifier at your location for Maghera, esp for DTT. There is no point using Tonabrucky as it is DTT only.

cauliflower69

Basically what Galway said, you could even get away with putting the VHF aerial in the attic. You'll be surprised as you'll also pull in a decent FM signal on the VHF aerial.

You could also use an internal Distribution amplifier with separate inputs for VHF / UHF meaning you wouldn't need an external Diplexer. May keep costs down a tad.

Galway

cauliflower69 wrote: »

Basically what Galway said, you could even get away with putting the VHF aerial in the attic. You'll be surprised as you'll also pull in a decent FM signal on the VHF aerial.

You could also use an internal Distribution amplifier with separate inputs for VHF / UHF meaning you wouldn't need an external Diplexer. May keep costs down a tad.

You are far better off putting both aerials outside.

I made that very point re the distribution amp eliminating the need for an external VHF-UHF diplexer in my previous post.

FM is Band 2 and the RTÉ 1 & 2 aerial is VHF band 3 - a significant difference in the size of band 2 and band 3 aerials. Rarely is Band 3 much good for out of Band 2 FM signals - thats why FM aerials are manufactured. You'd be better off with a single band 2 dipole or similar length of cable than using a band 3 TV aerial. Shortcutting rarely produces satisfactory results - if you want the best TV pictures / Stereo FM available in your area - then use quality products and aerials of the correct group and type. Advising short cuts is only likely to produce headaches down the line for the ordinary guy attempting a DIY installation.

Randyleprechaun

Galway wrote: »

You are far better off putting both aerials outside.

I made that very point re the distribution amp eliminating the need for an external VHF-UHF diplexer in my previous post.

FM is Band 2 and the RTÉ 1 & 2 aerial is VHF band 3 - a significant difference in the size of band 2 and band 3 aerials. Rarely is Band 3 much good for out of Band 2 FM signals - thats why FM aerials are manufactured. You'd be better off with a single band 2 dipole or similar length of cable than using a band 3 TV aerial. Shortcutting rarely produces satisfactory results - if you want the best TV pictures / Stereo FM available in your area - then use quality products and aerials of the correct group and type. Advising short cuts is only likely to produce headaches down the line for the ordinary guy attempting a DIY installation.

I'd have to agree with Galway, put both aerials outside. The cost of the VHF aerial is well worth it for the fact that you will have perfect channels even on your older TV's for nearly 2 more years.

lucernarian

Galway wrote: »

You are far better off putting both aerials outside.

I made that very point re the distribution amp eliminating the need for an external VHF-UHF diplexer in my previous post.

FM is Band 2 and the RTÉ 1 & 2 aerial is VHF band 3 - a significant difference in the size of band 2 and band 3 aerials. Rarely is Band 3 much good for out of Band 2 FM signals - thats why FM aerials are manufactured. You'd be better off with a single band 2 dipole or similar length of cable than using a band 3 TV aerial. Shortcutting rarely produces satisfactory results - if you want the best TV pictures / Stereo FM available in your area - then use quality products and aerials of the correct group and type. Advising short cuts is only likely to produce headaches down the line for the ordinary guy attempting a DIY installation.

People seem to forget that an aerial need only be as good as the increase in gain over using a bit of wire or whatever's there currently. (Assuming no ghosting is involved). If a Band 3 aerial mounted in the attic works better than using a bit of wire connected to the radio on the ground floor, what's the harm in using that? If there's a need for higher gain, there's nothing stopping anyone from putting up a second band 2 aerial in the attic. My argument would be shortcutting rarely leaves you out of pocket.

I get crystal clear VHF from Kippure, 60km away albeit with line of sight, with a 7 element Band 3 aerial in the attic. The signal passes through the gable wall too, and Kippure VHF is a bit weaker than Maghera too. If I don't need to put an aerial outside, why would I? I know I would get higher gain but I think that would result in a signal overload if anything.

watty

Depends what your attic is made of, direction of TX site vs end walls, water tanks, angle of tiles etc.

Freeman

Thanks very much Galway. You really cleared up a lot of questions I had.

Should I buy a T&K Bracket and pole to mount the 2 Aerials and what height do the Aerials need to be? Same height as Satellite dish or higher? Do I need a 4 element or 7 element VHF aerial? This might seem like a strange question but are Birds going to be a problem if I mount this outside?

In terms of a Combo Receiver, any recommendations? I was looking at the Edision Argus 2in1, Qbox HD Mini, Mvision HD300, is there another combo receiver I should consider around €200?

watty

Use a strong pole!

Top is VHF FM omni Band II or a Discone (27MHz to 1200MHz, good for Scanner, FM Radio and DAB). Vertically polarised.

Next is UHF horizontal . Rotate 90 deg if vertical is needed.

larger aerial below is VHF TV Band III, horizontal . Rotate 90 deg if vertical is needed.

Dish closest to T & K Mount as it has most wind load and is looking upwards at 22 degrees, it needs no height, just LOS to South East

Vertical polarised Yagi for VHF/UHF need either a "stand off" from pole or pole acts as an element, or be small ones that clamp on pole behind reflector.

watty

Freeman wrote: »

In terms of a Combo Receiver, any recommendations? I was looking at the Edision Argus 2in1, Qbox HD Mini, Mvision HD300, is there another combo receiver I should consider around €200?

Do any of those do MHEG5? If not then only partial compatibility for Saorview. Also no Combos are properly Freesat compatible. That is a pain for ordinary people, esp. if they use BBC Interactive (Aus. Open at the mo).

Triax has a Combo shortly that is Saorview on DTT, and just FTA satellite, but may have some sort of Internet based EPG for Satellite.

Proper PVR for Irish TV & Freesat is problematic right now. I'd wait till June, if if desperate right now for actual TV, maybe go cheapest solution and not worry about PVR, and upgrade June/July.

It's about £40 for a refurbished Tesco Freeview HD box for Saorview and about €40 for a basic non-HD generic FTA Satellite box. Then later get one decent PVR.

Galway

Freeman wrote: »

Thanks very much Galway. You really cleared up a lot of questions I had.

Should I buy a T&K Bracket and pole to mount the 2 Aerials and what height do the Aerials need to be? Same height as Satellite dish or higher? Do I need a 4 element or 7 element VHF aerial? This might seem like a strange question but are Birds going to be a problem if I mount this outside?

In terms of a Combo Receiver, any recommendations? I was looking at the Edision Argus 2in1, Qbox HD Mini, Mvision HD300, is there another combo receiver I should consider around €200?

If you are mounting the aerials on a exterior house wall, yes you will need these and a pole, insulation tape to tape the cables to the pole before they enter the house. Mount them a bit higher than the sat dish, though I don't know where you have that located. A 7 element would be better as you intend feeding a number of sets via a distribution amp. A ten element UHF group C/D aerial should be adequate also. Yes birds do tend to perch on aerials, esp horizontally mounted ones, nothing can be done about that. Remember to space the aerials a metre apart on the pole with the UHF one on top, it will probably be a rear mounting type. One point to note with the VHF band 3 aerial is that the clamp to attach it to the pole must be placed after the dipole otherwise the pole itself will impair reception. This is especially important when mounting one of these aerials vertically.

As far as receivers are concerned Triax are shortly bringing out a combo DTT/Sat receiver/PVR . I have an Mvsion which is ok but Id need to get a hard drive to be able to use the recording facility.

Galway

watty wrote: »

Depends what your attic is made of, direction of TX site vs end walls, water tanks, angle of tiles etc.

Excellent point made there, Watty. Shortcutting often leads to headaches later for the DIY installer.

Freeman

@Watty: No they don't do MHEG5. I thought MHEG5 was just an upgraded Aertel but looking at the link you gave it seems it could offer much more in the future. I think you're right about waiting for a while and just getting the cheapest option now. Where do you get those 2 receivers you mentioned?

@Galway: The dish is approx 6m from the ground. It's a south facing wall with nasty pebbledash. I attached a rough sketch. The UHF is 10 element and I will get this 7 Element VHF unit. This is the Distribution box I was looking at. Do you know the name of the TRIAX for later?

watty

Triax http://www.techtir.ie/blog/watty/triax-for-saorview

Google Tesco Direct and also see Tesco outlet on eBay (yes really)

Almost everyone thinks MHEG5 is just an updated Teletext. The new Text is just one application mimicing Teletext content. Unlike Teletext which is fixed in stone spec that only does pages of text, originally implemented in hardware, MHEG5 is just an engine like Java on phones or Davik for Andriod Apps.

The current MHEG5 text is just an initial App, and unlike Teletext can be redesigned tomorrow.

Same with EPG. At the minute each box/TV is doing it's own manufacturer's implementation of displying standard "fixed in stone" spec DVB EIT data. An MHEG5 EPG app can be much better and the same on every TV. Even option for small layout (small HDTVs and SD TVs) or HiRes layout (large HDTVs) under user selection if RTEN NL wants.

Freeman

From what I can tell neither Tesco Direct nor the eBay outlet ship to a ROI address or am I missing something obvious?

I was looking at this Xoro 3000 for a SD FTA Receiver at €53.24.

For Saorview, I think it makes more sense to wait and see what gets released over the next few months and just make do with Analog. I really was looking forward to having 3e, ah well.

Galway

Freeman wrote: »

@Watty: No they don't do MHEG5. I thought MHEG5 was just an upgraded Aertel but looking at the link you gave it seems it could offer much more in the future. I think you're right about waiting for a while and just getting the cheapest option now. Where do you get those 2 receivers you mentioned?

@Galway: The dish is approx 6m from the ground. It's a south facing wall with nasty pebbledash. I attached a rough sketch. The UHF is 10 element and I will get this 7 Element VHF unit. This is the Distribution box I was looking at. Do you know the name of the TRIAX for later?

All that equipment seems fine. The aerial will need to clear the eaves really if its a bungalow and needs to be clear of local obstructions like next doors garden wall, trees etc. Theres post on the boards somewhere re the TRIAX box.

lucernarian

watty wrote: »

Depends what your attic is made of, direction of TX site vs end walls, water tanks, angle of tiles etc.

That's exactly why people should try with what existing materials and equipment they have, before committing to further expense. There is no justification for putting a second aerial outside if that aerial does work perfectly within an attic space and that there is space in said attic.

In my experience, most long-term problems come from the outdoor aspect of aerials and masthead amps and particularly cabling. An outdoor aerial will be less reliable than the same aerial under a roof in all but the most unlikely circumstances. Cable always wears out with UV and friction damage, people and animals (usually birds) can knock and damage aerial parts and cable over the years etc. Aesthetically, a bigger VHF aerial would be preferable indoors. I do maintain that any aerial is better off in the loftif there's no discernible loss of analogue picture quality. And if you're not interested in DXing of course:)

It's unlikely that a UHF aerial will work in a loft with no loss of analogue quality however, based on what I've worked at in the past.

watty

I always tell people I'm sorting, or if I'm doing stuff for someone, try attic first but assume in planning, ladders etc that 10min later you will be fitting the Aerial outdoors.

Sponge Bob

I live further from Maghera than the OP and pick up RTE VHF on a C/D UHF in the attic but one that is amplified. It is clear of tanks and chimneys. As a sop to VHF it is aligned vertical.

When I abandon VHF in late 2012 I will align horizontal and reduce the amplification. Maghera is supposed to increase output around then anyway.

Peter Rhea

To_be_confirmed wrote: »

In my experience, most long-term problems come from the outdoor aspect of aerials and masthead amps and particularly cabling. An outdoor aerial will be less reliable than the same aerial under a roof in all but the most unlikely circumstances. Cable always wears out with UV and friction damage, people and animals (usually birds) can knock and damage aerial parts and cable over the years etc. Aesthetically, a bigger VHF aerial would be preferable indoors. . .

Seriously? Anyway, it makes me laugh when people talk about having 'line of sight' to a transmitter & then stick their own roof (or gable wall) in the way . . .

lucernarian

Peter Rhea wrote: »

Seriously? Anyway, it makes me laugh when people talk about having 'line of sight' to a transmitter & then stick their own roof (or gable wall) in the way . . .

I believe one can say that their house or premises has line-of-sight to somewhere and then use that fact to install an antenna within that house. To add to that, surely it's obvious that the weather and birds and human activity will take its toll on even the most appropriately installed outdoor aerial?

Sponge Bob

To_be_confirmed wrote: »

To add to that, surely it's obvious that the weather and birds and human activity will take its toll on even the most appropriately installed outdoor aerial?

That is exactly the problem I have near the west coast, that is why the gear is indoors.

Peter Rhea

To_be_confirmed wrote: »

I believe one can say that their house or premises has line-of-sight to somewhere and then use that fact to install an antenna within that house. To add to that, surely it's obvious that the weather and birds and human activity will take its toll on even the most appropriately installed outdoor aerial?

I would have thought that the RX aerial itself should have the best possible view of the TX.
Your own roof or wall is no different than any other obstruction or clutter & I've yet to meet anyone who values the welfare of pieces of metal and some cable over reliable tv reception.
But, I suppose if it works . . .

lucernarian

Peter Rhea wrote:

...reliable tv reception...

How can it be "reliable" if the aerial and cable starts to disintegrate after a few years (at best, in more exposed locations)??

An aerial, if it works perfectly at installation, will continue working just fine inside a loft barring any problems with impulse noise. Now the attenuation of a wall remains constant but tiles can vary depending on any rain or snow present. That effect appears to be insignificant for VHF when I tried for reception for Mullaghanish. Very weak signal (could barely get a sound lock and was in very snowy black and white) but it never varied between dry or wet conditions.

watty

Decent quality aerial and coax can last 10 to 20 years, or even more. Cheap stuff barely a year. I have an outdoor aerial that's over 25 years old that I just recently refurbished.

Effect of wet/dry tiles depends on the angle of signal, frequency and material of tiles. Also the liner under the tiles.

In medium to strong signal areas, in the attic may be fine on VHF. On UHF I have only seen it good once.

Galway

watty wrote: »

Decent quality aerial and coax can last 10 to 20 years, or even more. Cheap stuff barely a year. I have an outdoor aerial that's over 25 years old that I just recently refurbished.

Effect of wet/dry tiles depends on the angle of signal, frequency and material of tiles. Also the liner under the tiles.

In medium to strong signal areas, in the attic may be fine on VHF. On UHF I have only seen it good once.

Watty is talking a lot of sense. I am local to the area and I can tell you it will waste more time putting it inside, scrimping on materials and the right type and groups of aerials. Good stuff will last, it designed to go outside!

cauliflower69

If you can get perfect picture inside, leave it inside. Also, I never stated that the VHF aerial was designed for FM I merely stated that you'd be surprised on what you could receive.