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#1
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
HI All
A tiny bit Off Topic - but if I can't get any joy out of the people I've paid to do this job then I may end up DIY-ing it myself ! There was a discussion a few months back about the practicalities of DIY setting up for a sky+ system out here in West Cork. General consensus seemed to be that it wasn't such a difficult task - but, in the end, time constraints cut in and I got a man in g Result is that we have a little (oval - perhaps 80cm ?) sat dish up on the gable end - with a clear view of the sky.... This is mostly OK (signal stength on channel 1 is about 50%, quality about 25%, Stength on channel 2 is lower and quality doesn't even indicate on the scale) - with a little 'stuttering' and picture freezing from time to time. When we have a heavy downpour the signal disappears altogether - which means that the sky+ box gives up on any recordings that we're trying to do. Should we expect this situation (about the signal strength) - we're out in the West of County Cork, near a little place called Ballydehob. The same 'expert installers' ( it says so on their van !) fitted an aerial for Terrestrial Irish TV. We are about 5 miles direct line of sight from the transmitter at Mount Gabriel - and getting a noticeably snowy picture with some ghosting. The aerial is a 4 dipole + reflector arrangement, that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... To be fair - they did say that if we weren't happy then they'd come back & fit the aerial outside... So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... Advice appreciated - thanks in advance Adrian |
#2
Posted to uk.d-i-y
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
"Adrian" wrote in message ... HI All A tiny bit Off Topic - but if I can't get any joy out of the people I've paid to do this job then I may end up DIY-ing it myself ! There was a discussion a few months back about the practicalities of DIY setting up for a sky+ system out here in West Cork. General consensus seemed to be that it wasn't such a difficult task - but, in the end, time constraints cut in and I got a man in g Result is that we have a little (oval - perhaps 80cm ?) sat dish up on the gable end - with a clear view of the sky.... This is mostly OK (signal stength on channel 1 is about 50%, quality about 25%, Stength on channel 2 is lower and quality doesn't even indicate on the scale) - with a little 'stuttering' and picture freezing from time to time. When we have a heavy downpour the signal disappears altogether - which means that the sky+ box gives up on any recordings that we're trying to do. Should we expect this situation (about the signal strength) - we're out in the West of County Cork, near a little place called Ballydehob. SKY , who now seem to broadcast to Irish consumers - judging from the 'Ireland' options when one 'presses the red button' - would be the definitive expert on what signal strength they aniticipate at that Lat Long. {They will have a map of the satellite's broadcast 'footprint'}. however a more practical approach may be to wander around your neighbourhood looking out for 'dishes' on the south-east facades of houses and ask them what their experience is. Neighbours with dishes may say ' Our symptoms are precisely as yours! ' OR 'No, we get a perfect picture!' Either way you'll get a rapid response and then now how to proceed. AIUI, Channel 1 and 2 (off the quad LNB) are irrelevant as you may be watching say Sky-One on Channel 1 or 2 so the signal strength should be the same! Channel 1 AUI is the defaul and feeds the recorder while Channel 2 becomes the alternate. You may have a dodgy Sky+ box and Channel 2's chain is duff (to use a technical term). In UK Sky has a phone-line which will offer advise. The same 'expert installers' ( it says so on their van !) fitted an aerial for Terrestrial Irish TV. We are about 5 miles direct line of sight from the transmitter at Mount Gabriel - and getting a noticeably snowy picture with some ghosting. The aerial is a 4 dipole + reflector arrangement, A TV aerial, properly called a Yagi Array, only has one proper dipole (sometimes folded) this dipole is in fornt of the reflector and is where the signal is received. The other elements are properly called 'directors' and contribute to received power by both adding to the signal [Gain] AND making the beam more narrow [Beam width] - requiring 'better' pointing. Four dipoles plus reflector - three directors(?) doesn't seem at first glance to be very directional - glancing out of my window at neighbouring yagi arrays I count seven directors poiting at a transmitter in visual range on top of a hill perhaps six miles away. Three directors might indicate a low gain wide beamwidth array. ............ that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... A high gain amplifier will increase the noise just as much as the signal and may swamp the input stages of your receivers. It's the wrong way round _ I'd say an oirish way - but that's probably banned by some legislation or other ; so I won't_. You need to have a good signal off the dipole. To be fair - they did say that if we weren't happy then they'd come back & fit the aerial outside... It's _may_ not be the inide/outside aspectthat's wrong but the GAIN/BEAMWIDTH that's incorrectly supplied. BTW, with direct line-of-sight there's perhaps multiple paths for the signal to reach you You haven't mentioned the juxtapositioning of the 'enormous' steel to the yagi; nor the orientation of the steel to the transmitter (aligned/broadside on/ skewed. Perhaps the signal is bouncing off and your device is 'receiving' a back-lobe? So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... There are _no_ 'good euro' .... Advice appreciated - thanks in advance Adrian -- Brian |
#3
Posted to uk.d-i-y
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
On 2006-10-16 07:57:13 +0100, Adrian said:
HI All A tiny bit Off Topic - but if I can't get any joy out of the people I've paid to do this job then I may end up DIY-ing it myself ! There was a discussion a few months back about the practicalities of DIY setting up for a sky+ system out here in West Cork. General consensus seemed to be that it wasn't such a difficult task - but, in the end, time constraints cut in and I got a man in g Result is that we have a little (oval - perhaps 80cm ?) sat dish up on the gable end - with a clear view of the sky.... This is mostly OK (signal stength on channel 1 is about 50%, quality about 25%, Stength on channel 2 is lower and quality doesn't even indicate on the scale) - with a little 'stuttering' and picture freezing from time to time. When we have a heavy downpour the signal disappears altogether - which means that the sky+ box gives up on any recordings that we're trying to do. Should we expect this situation (about the signal strength) - we're out in the West of County Cork, near a little place called Ballydehob. Basically the dish isn't large enough. Signal strength needs to be higher, but more importantly the signal quality. It may be possible to make *some* improvement with a better quality LNB on the dish but this is usually a second order thing. The same 'expert installers' ( it says so on their van !) fitted an aerial for Terrestrial Irish TV. We are about 5 miles direct line of sight from the transmitter at Mount Gabriel - and getting a noticeably snowy picture with some ghosting. The aerial is a 4 dipole + reflector arrangement, that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... This is pointless. Adding an amplifier when the signal is poor adds noise as well and doesn;t improve multipath reception. To be fair - they did say that if we weren't happy then they'd come back & fit the aerial outside... I think you should ask them to do that, to be sure. So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... It should have gone outside in the first place, Advice appreciated - thanks in advance Adrian |
#4
Posted to uk.d-i-y
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
In article , Adrian
writes HI All A tiny bit Off Topic - but if I can't get any joy out of the people I've paid to do this job then I may end up DIY-ing it myself ! There was a discussion a few months back about the practicalities of DIY setting up for a sky+ system out here in West Cork. General consensus seemed to be that it wasn't such a difficult task - but, in the end, time constraints cut in and I got a man in g Result is that we have a little (oval - perhaps 80cm ?) sat dish up on the gable end - with a clear view of the sky.... This is mostly OK (signal stength on channel 1 is about 50%, quality about 25%, Stength on channel 2 is lower and quality doesn't even indicate on the scale) - with a little 'stuttering' and picture freezing from time to time. Bigger dish required!. See also http://www.astra2d.co.uk and a post to alt.satellite.tv.europe When we have a heavy downpour the signal disappears altogether - which means that the sky+ box gives up on any recordings that we're trying to do. Should we expect this situation (about the signal strength) - we're out in the West of County Cork, near a little place called Ballydehob. The same 'expert installers' ( it says so on their van !) fitted an aerial for Terrestrial Irish TV. We are about 5 miles direct line of sight from the transmitter at Mount Gabriel - and getting a noticeably snowy picture with some ghosting. The aerial is a 4 dipole + reflector arrangement, that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... Kick them out and try to find someone who knows that their doing or DIY that is a total crap way of going about TV reception!.. To be fair - they did say that if we weren't happy then they'd come back & fit the aerial outside... Yes what they should have done in the first place. If it were me I'd be demanding my money back at this point!. Unless you told them to put it there against their advice.. And a post to uk.tech.digital-tv might turn up someone recommendable in your area but good aerial riggers are like finding virgins in Cardiff.) So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... Advice appreciated - thanks in advance Adrian -- Tony Sayer |
#5
Posted to uk.d-i-y
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
Result is that we have a little (oval - perhaps 80cm ?) sat dish up on
the gable end - with a clear view of the sky.... You need a bigger dish, probably round, not the little ovals you can use in SE England. The aerial is a 4 dipole + reflector arrangement, that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... Ditch the amplifier. Waste of time. Amplifiers compensate for long downleads or splitting. They are no good for rescuing below par aerial installations. You have ghosting. There could be two causes of this. Firstly, your noisy loft installation. Secondly, being close to a high power transmitter. I can't say which problem you have. The first will be fixed by installing outside. The second would be fixed by using a log periodic aerial instead of a Yagi. Log periodics have lowish gain (but do you care?) but, more importantly, are very good at eliminating reflections without all the spurious peaks you get on a Yagi response chart. You basically point at the transmitter and get a good signal. If you have a really stubborn fixed reflection, such as off a large building or mountain, you might need something more exotic, such as a Yagi phased array, although these can be very problematic to set up (particularly wideband) and are very sensitive to slippage from being blown around. Christian. |
#6
Posted to uk.d-i-y
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
Hi Brian
Thanks for the reply... On Mon, 16 Oct 2006 07:35:51 GMT, "Brian Sharrock" wrote: "Adrian" wrote in message .. . HI All A tiny bit Off Topic - but if I can't get any joy out of the people I've paid to do this job then I may end up DIY-ing it myself ! There was a discussion a few months back about the practicalities of DIY setting up for a sky+ system out here in West Cork. General consensus seemed to be that it wasn't such a difficult task - but, in the end, time constraints cut in and I got a man in g Result is that we have a little (oval - perhaps 80cm ?) sat dish up on the gable end - with a clear view of the sky.... This is mostly OK (signal stength on channel 1 is about 50%, quality about 25%, Stength on channel 2 is lower and quality doesn't even indicate on the scale) - with a little 'stuttering' and picture freezing from time to time. When we have a heavy downpour the signal disappears altogether - which means that the sky+ box gives up on any recordings that we're trying to do. Should we expect this situation (about the signal strength) - we're out in the West of County Cork, near a little place called Ballydehob. SKY , who now seem to broadcast to Irish consumers - judging from the 'Ireland' options when one 'presses the red button' - would be the definitive expert on what signal strength they aniticipate at that Lat Long. {They will have a map of the satellite's broadcast 'footprint'}. however a more practical approach may be to wander around your neighbourhood looking out for 'dishes' on the south-east facades of houses and ask them what their experience is. Neighbours with dishes may say ' Our symptoms are precisely as yours! ' OR 'No, we get a perfect picture!' Either way you'll get a rapid response and then now how to proceed. Don't have many neighbours out here g - but I have asked a few locals and they seem to be able to get acceptable reception. AIUI, Channel 1 and 2 (off the quad LNB) are irrelevant as you may be watching say Sky-One on Channel 1 or 2 so the signal strength should be the same! Channel 1 AUI is the defaul and feeds the recorder while Channel 2 becomes the alternate. You may have a dodgy Sky+ box and Channel 2's chain is duff (to use a technical term). In UK Sky has a phone-line which will offer advise. It did seem a bit strange to me. Maybe I'll swap the plugs from the wall to the sky-box and see if the fault moves (nail through a cable, anybody ? g) Might also take a look in the loft and see what sort of cable the electrician installed - wonder if it's proper satellite stuff ? I've a sneaking suspicion that the joins between the existing 'house' cabling and the new dish were of the 'insulation tape & three Hail Marys' variety - could be something odd going on there..? The same 'expert installers' ( it says so on their van !) fitted an aerial for Terrestrial Irish TV. We are about 5 miles direct line of sight from the transmitter at Mount Gabriel - and getting a noticeably snowy picture with some ghosting. The aerial is a 4 dipole + reflector arrangement, A TV aerial, properly called a Yagi Array, only has one proper dipole (sometimes folded) this dipole is in fornt of the reflector and is where the signal is received. The other elements are properly called 'directors' and contribute to received power by both adding to the signal [Gain] AND making the beam more narrow [Beam width] - requiring 'better' pointing. Four dipoles plus reflector - three directors(?) doesn't seem at first glance to be very directional - glancing out of my window at neighbouring yagi arrays I count seven directors poiting at a transmitter in visual range on top of a hill perhaps six miles away. Three directors might indicate a low gain wide beamwidth array. Nope - I guess this is a form of 'curtain' array - four little 'bow-tie' elements sitting in front of a mesh reflector. All 'fitted' in the loft by the expedient of nailing the reflector to a roof-joist (!) - although the installer did use a signal-strength meter to set it up.... ............ that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... A high gain amplifier will increase the noise just as much as the signal and may swamp the input stages of your receivers. It's the wrong way round _ I'd say an oirish way - but that's probably banned by some legislation or other ; so I won't_. You need to have a good signal off the dipole. I thought as much - but thanks for confirming that I'm on the right track... To be fair - they did say that if we weren't happy then they'd come back & fit the aerial outside... It's _may_ not be the inide/outside aspectthat's wrong but the GAIN/BEAMWIDTH that's incorrectly supplied. BTW, with direct line-of-sight there's perhaps multiple paths for the signal to reach you You haven't mentioned the juxtapositioning of the 'enormous' steel to the yagi; nor the orientation of the steel to the transmitter (aligned/broadside on/ skewed. Perhaps the signal is bouncing off and your device is 'receiving' a back-lobe? The house is pretty much 'gable on' to the transmitter - so the aerial is looking through the end gable wall, a small internal wall, and 'along' the line of the big metal beam. Plenty of room for relections / multiple signal paths there ! So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... There are _no_ 'good euro' .... There are when they are buying petrol at 2/3 the UK price over here ! g Many thanks - I'll go investigate Regards Adrian Advice appreciated - thanks in advance Adrian |
#7
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
HI Andy
On Mon, 16 Oct 2006 09:11:53 +0100, Andy Hall wrote: On 2006-10-16 07:57:13 +0100, Adrian said: HI All A tiny bit Off Topic - but if I can't get any joy out of the people I've paid to do this job then I may end up DIY-ing it myself ! There was a discussion a few months back about the practicalities of DIY setting up for a sky+ system out here in West Cork. General consensus seemed to be that it wasn't such a difficult task - but, in the end, time constraints cut in and I got a man in g Result is that we have a little (oval - perhaps 80cm ?) sat dish up on the gable end - with a clear view of the sky.... This is mostly OK (signal stength on channel 1 is about 50%, quality about 25%, Stength on channel 2 is lower and quality doesn't even indicate on the scale) - with a little 'stuttering' and picture freezing from time to time. When we have a heavy downpour the signal disappears altogether - which means that the sky+ box gives up on any recordings that we're trying to do. Should we expect this situation (about the signal strength) - we're out in the West of County Cork, near a little place called Ballydehob. Basically the dish isn't large enough. Signal strength needs to be higher, but more importantly the signal quality. My thoughts entirely Why would they fit a 'too small' dish ? Seems to be asking for trouble It may be possible to make *some* improvement with a better quality LNB on the dish but this is usually a second order thing. The same 'expert installers' ( it says so on their van !) fitted an aerial for Terrestrial Irish TV. We are about 5 miles direct line of sight from the transmitter at Mount Gabriel - and getting a noticeably snowy picture with some ghosting. The aerial is a 4 dipole + reflector arrangement, that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... This is pointless. Adding an amplifier when the signal is poor adds noise as well and doesn;t improve multipath reception. Thanks - you're confirming my suspicions g - wanted to be sure before tackilng them... To be fair - they did say that if we weren't happy then they'd come back & fit the aerial outside... I think you should ask them to do that, to be sure. g To be sure g So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... It should have gone outside in the first place, I guess the only thing in their defence was that it was pouring down at the time - but, working in the Emerald Isle you tend to expect that! Thanks again Adrian |
#8
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
Hi Tony
On Mon, 16 Oct 2006 09:12:27 +0100, tony sayer wrote: In article , Adrian writes HI All A tiny bit Off Topic - but if I can't get any joy out of the people I've paid to do this job then I may end up DIY-ing it myself ! There was a discussion a few months back about the practicalities of DIY setting up for a sky+ system out here in West Cork. General consensus seemed to be that it wasn't such a difficult task - but, in the end, time constraints cut in and I got a man in g Result is that we have a little (oval - perhaps 80cm ?) sat dish up on the gable end - with a clear view of the sky.... This is mostly OK (signal stength on channel 1 is about 50%, quality about 25%, Stength on channel 2 is lower and quality doesn't even indicate on the scale) - with a little 'stuttering' and picture freezing from time to time. Bigger dish required!. See also http://www.astra2d.co.uk and a post to alt.satellite.tv.europe Thanks.... Does a 'too small' dish explain why there's the difference in signal strength between the two channels ? When we have a heavy downpour the signal disappears altogether - which means that the sky+ box gives up on any recordings that we're trying to do. Should we expect this situation (about the signal strength) - we're out in the West of County Cork, near a little place called Ballydehob. The same 'expert installers' ( it says so on their van !) fitted an aerial for Terrestrial Irish TV. We are about 5 miles direct line of sight from the transmitter at Mount Gabriel - and getting a noticeably snowy picture with some ghosting. The aerial is a 4 dipole + reflector arrangement, that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... Kick them out and try to find someone who knows that their doing or DIY that is a total crap way of going about TV reception!.. Thought as much.... To be fair - they did say that if we weren't happy then they'd come back & fit the aerial outside... Yes what they should have done in the first place. If it were me I'd be demanding my money back at this point!. Unless you told them to put it there against their advice.. Nope - didn't advise them either way..... - after all - it says 'expert' on their van g And a post to uk.tech.digital-tv might turn up someone recommendable in your area but good aerial riggers are like finding virgins in Cardiff.) Can't say I've ever tried that g Thanks again Adrian |
#9
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
Hi Christian
On Mon, 16 Oct 2006 14:53:13 +0100, "Christian McArdle" wrote: Result is that we have a little (oval - perhaps 80cm ?) sat dish up on the gable end - with a clear view of the sky.... You need a bigger dish, probably round, not the little ovals you can use in SE England. So I was told before we moved out here - but I thought the 'experts' would know what they were doing ? The aerial is a 4 dipole + reflector arrangement, that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... Ditch the amplifier. Waste of time. Amplifiers compensate for long downleads or splitting. They are no good for rescuing below par aerial installations. Thanks - you're confirming my own suspicions You have ghosting. There could be two causes of this. Firstly, your noisy loft installation. Secondly, being close to a high power transmitter. I can't say which problem you have. Not sure how much power the transmitter is putting out - about 2kw according to Wolfbane The first will be fixed by installing outside. The second would be fixed by using a log periodic aerial instead of a Yagi. Log periodics have lowish gain (but do you care?) but, more importantly, are very good at eliminating reflections without all the spurious peaks you get on a Yagi response chart. You basically point at the transmitter and get a good signal. The existing aerial's a sort of '4 dipoles and a single mesh reflector' arrangement - not a Yagi If you have a really stubborn fixed reflection, such as off a large building or mountain, you might need something more exotic, such as a Yagi phased array, although these can be very problematic to set up (particularly wideband) and are very sensitive to slippage from being blown around. Wouldn't think we'll need that.... Thanks - I'll call them back in Adrian |
#10
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
"Adrian" wrote in message ... Hi Brian Thanks for the reply... On Mon, 16 Oct 2006 07:35:51 GMT, "Brian Sharrock" wrote: "Adrian" wrote in message . .. HI All A tiny bit Off Topic - but if I can't get any joy out of the people I've paid to do this job then I may end up DIY-ing it myself ! There was a discussion a few months back about the practicalities of DIY setting up for a sky+ system out here in West Cork. General consensus seemed to be that it wasn't such a difficult task - but, in the end, time constraints cut in and I got a man in g Result is that we have a little (oval - perhaps 80cm ?) sat dish up on the gable end - with a clear view of the sky.... This is mostly OK (signal stength on channel 1 is about 50%, quality about 25%, Stength on channel 2 is lower and quality doesn't even indicate on the scale) - with a little 'stuttering' and picture freezing from time to time. The SKY+ box has two channels internally but are both fed off the one aerial. This aerial is actually a reflecting dish focussing the teeny-weeny signals off the satellite onto a Quad LNB - the cables -from the SKY+ box are sending a DC signal to the LNB's which sets up each exercised LNB solid -state device to 'tune-into' the desired frequency and orientation of the satellite's many signals. Get a decent signal on Chanell 1, swap over the cables; the signal strength should be exactly the same - it it isn't then you've got a faulty SKY+ box; if they change then you've got a faulty Quad LNB. {Or faulty cables/connectors } When we have a heavy downpour the signal disappears altogether - which means that the sky+ box gives up on any recordings that we're trying to do. Should we expect this situation (about the signal strength) - we're out in the West of County Cork, near a little place called Ballydehob. SKY , who now seem to broadcast to Irish consumers - judging from the 'Ireland' options when one 'presses the red button' - would be the definitive expert on what signal strength they aniticipate at that Lat Long. {They will have a map of the satellite's broadcast 'footprint'}. however a more practical approach may be to wander around your neighbourhood looking out for 'dishes' on the south-east facades of houses and ask them what their experience is. Neighbours with dishes may say ' Our symptoms are precisely as yours! ' OR 'No, we get a perfect picture!' Either way you'll get a rapid response and then now how to proceed. Don't have many neighbours out here g - but I have asked a few locals and they seem to be able to get acceptable reception. So, if they can get it - so should you ! Complain to SKY! AIUI, Channel 1 and 2 (off the quad LNB) are irrelevant as you may be watching say Sky-One on Channel 1 or 2 so the signal strength should be the same! Channel 1 AUI is the defaul and feeds the recorder while Channel 2 becomes the alternate. You may have a dodgy Sky+ box and Channel 2's chain is duff (to use a technical term). In UK Sky has a phone-line which will offer advise. It did seem a bit strange to me. Maybe I'll swap the plugs from the wall to the sky-box and see if the fault moves (nail through a cable, anybody ? g) Might also take a look in the loft and see what sort of cable the electrician installed - wonder if it's proper satellite stuff ? I've a sneaking suspicion that the joins between the existing 'house' cabling and the new dish were of the 'insulation tape & three Hail Marys' variety - could be something odd going on there..? The same 'expert installers' ( it says so on their van !) fitted an aerial for Terrestrial Irish TV. We are about 5 miles direct line of sight from the transmitter at Mount Gabriel - and getting a noticeably snowy picture with some ghosting. The aerial is a 4 dipole + reflector arrangement, A TV aerial, properly called a Yagi Array, only has one proper dipole (sometimes folded) this dipole is in fornt of the reflector and is where the signal is received. The other elements are properly called 'directors' and contribute to received power by both adding to the signal [Gain] AND making the beam more narrow [Beam width] - requiring 'better' pointing. Four dipoles plus reflector - three directors(?) doesn't seem at first glance to be very directional - glancing out of my window at neighbouring yagi arrays I count seven directors poiting at a transmitter in visual range on top of a hill perhaps six miles away. Three directors might indicate a low gain wide beamwidth array. Nope - I guess this is a form of 'curtain' array - four little 'bow-tie' elements sitting in front of a mesh reflector. All 'fitted' in the loft by the expedient of nailing the reflector to a roof-joist (!) - although the installer did use a signal-strength meter to set it up.... ............ that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... A high gain amplifier will increase the noise just as much as the signal and may swamp the input stages of your receivers. It's the wrong way round _ I'd say an oirish way - but that's probably banned by some legislation or other ; so I won't_. You need to have a good signal off the dipole. I thought as much - but thanks for confirming that I'm on the right track... To be fair - they did say that if we weren't happy then they'd come back & fit the aerial outside... It's _may_ not be the inide/outside aspectthat's wrong but the GAIN/BEAMWIDTH that's incorrectly supplied. BTW, with direct line-of-sight there's perhaps multiple paths for the signal to reach you You haven't mentioned the juxtapositioning of the 'enormous' steel to the yagi; nor the orientation of the steel to the transmitter (aligned/broadside on/ skewed. Perhaps the signal is bouncing off and your device is 'receiving' a back-lobe? The house is pretty much 'gable on' to the transmitter - so the aerial is looking through the end gable wall, a small internal wall, and 'along' the line of the big metal beam. Plenty of room for relections / multiple signal paths there ! I haven't been able to sight "Ballydehob " on Google Earth's site! 'Ballydehob' isn't the Gaelic for "valley of no signal" is it? So I don't know where abouts you are in relationship to Mount Gabriel - {Truthfully; I don't now where that is either! Do you ever get trumpet blasts?} An Irish outfit that claims some expertise in terrestial Television - it probalby says so on their vans :- recommends:- NEW UHF TRANSMITTER ON AIR AT MOUNT GABRIEL, CO CORK RTE 1 NETWORK 2 TG4 Channel 29 Channel 33 Channel 23 For best reception for viewers, a UHF Group A or broadband aerial should be used. For the east and south, aerials should be horizontally polarised. For the north and west, aerials should be vertically polarised. So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... There are _no_ 'good euro' .... There are when they are buying petrol at 2/3 the UK price over here ! g Many thanks - I'll go investigate Regards Adrian Advice appreciated - thanks in advance Adrian -- Brian |
#11
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
On 2006-10-16 18:28:10 +0100, Adrian said:
HI Andy Basically the dish isn't large enough. Signal strength needs to be higher, but more importantly the signal quality. My thoughts entirely Why would they fit a 'too small' dish ? Seems to be asking for trouble Perhaps this is what the distributor had in stock and told them it was OK. It may be possible to make *some* improvement with a better quality LNB on the dish but this is usually a second order thing. The same 'expert installers' ( it says so on their van !) fitted an aerial for Terrestrial Irish TV. We are about 5 miles direct line of sight from the transmitter at Mount Gabriel - and getting a noticeably snowy picture with some ghosting. The aerial is a 4 dipole + reflector arrangement, that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... This is pointless. Adding an amplifier when the signal is poor adds noise as well and doesn;t improve multipath reception. Thanks - you're confirming my suspicions g - wanted to be sure before tackilng them... To be fair - they did say that if we weren't happy then they'd come back & fit the aerial outside... I think you should ask them to do that, to be sure. g To be sure g So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... It should have gone outside in the first place, I guess the only thing in their defence was that it was pouring down at the time - but, working in the Emerald Isle you tend to expect that! You would. Also, as you've discovered, satellite signal strength drops when it's raining. However, it's really the error rate that counts. The other thing to do before they come back is to take a look at this site http://www.lyngsat.com/packages/skyuk.html For the satellite bands used by Sky, (and many others), there are two bands (high and low) and vertically and horizontally polarised signals. When you select the program you want to watch on the receiver, it sends appropriate control signals up the cable to the LNB at the dish to select which of the 4 permutations should be used - it as actually the LNB that does the band and polarisation selection. What I would recommend is to choose a program at the bottom, middle and top of each band and of each polarisation (i.e. 12 programs altogether). Note them down with the Sky channel numbers. Then when the installers come back, try them all out and make sure they are OK, ideally when it's raining. If all of this works reliably, then you can be reasonably confident that all channels will. Thanks again Adrian |
#12
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
HI Brian
On Mon, 16 Oct 2006 18:10:38 GMT, "Brian Sharrock" wrote: "Adrian" wrote in message .. . Hi Brian Thanks for the reply... On Mon, 16 Oct 2006 07:35:51 GMT, "Brian Sharrock" wrote: "Adrian" wrote in message ... HI All A tiny bit Off Topic - but if I can't get any joy out of the people I've paid to do this job then I may end up DIY-ing it myself ! There was a discussion a few months back about the practicalities of DIY setting up for a sky+ system out here in West Cork. General consensus seemed to be that it wasn't such a difficult task - but, in the end, time constraints cut in and I got a man in g Result is that we have a little (oval - perhaps 80cm ?) sat dish up on the gable end - with a clear view of the sky.... This is mostly OK (signal stength on channel 1 is about 50%, quality about 25%, Stength on channel 2 is lower and quality doesn't even indicate on the scale) - with a little 'stuttering' and picture freezing from time to time. The SKY+ box has two channels internally but are both fed off the one aerial. This aerial is actually a reflecting dish focussing the teeny-weeny signals off the satellite onto a Quad LNB - the cables -from the SKY+ box are sending a DC signal to the LNB's which sets up each exercised LNB solid -state device to 'tune-into' the desired frequency and orientation of the satellite's many signals. Get a decent signal on Chanell 1, swap over the cables; the signal strength should be exactly the same - it it isn't then you've got a faulty SKY+ box; if they change then you've got a faulty Quad LNB. {Or faulty cables/connectors } Will do that check later on tonight..... (when the box is not 'in use')! I did take a look in the loft, and the joints between the dish coax and the downlead in the walls are simply 'wrapped & insulating tape' - maybe there's a cock-up there ?? When we have a heavy downpour the signal disappears altogether - which means that the sky+ box gives up on any recordings that we're trying to do. Should we expect this situation (about the signal strength) - we're out in the West of County Cork, near a little place called Ballydehob. SKY , who now seem to broadcast to Irish consumers - judging from the 'Ireland' options when one 'presses the red button' - would be the definitive expert on what signal strength they aniticipate at that Lat Long. {They will have a map of the satellite's broadcast 'footprint'}. however a more practical approach may be to wander around your neighbourhood looking out for 'dishes' on the south-east facades of houses and ask them what their experience is. Neighbours with dishes may say ' Our symptoms are precisely as yours! ' OR 'No, we get a perfect picture!' Either way you'll get a rapid response and then now how to proceed. Don't have many neighbours out here g - but I have asked a few locals and they seem to be able to get acceptable reception. So, if they can get it - so should you ! Complain to SKY! Kit was installed by an independant installer - Skybox still thinks it lives in the UK (long & complicated story) AIUI, Channel 1 and 2 (off the quad LNB) are irrelevant as you may be watching say Sky-One on Channel 1 or 2 so the signal strength should be the same! Channel 1 AUI is the defaul and feeds the recorder while Channel 2 becomes the alternate. You may have a dodgy Sky+ box and Channel 2's chain is duff (to use a technical term). In UK Sky has a phone-line which will offer advise. It did seem a bit strange to me. Maybe I'll swap the plugs from the wall to the sky-box and see if the fault moves (nail through a cable, anybody ? g) Might also take a look in the loft and see what sort of cable the electrician installed - wonder if it's proper satellite stuff ? I've a sneaking suspicion that the joins between the existing 'house' cabling and the new dish were of the 'insulation tape & three Hail Marys' variety - could be something odd going on there..? The same 'expert installers' ( it says so on their van !) fitted an aerial for Terrestrial Irish TV. We are about 5 miles direct line of sight from the transmitter at Mount Gabriel - and getting a noticeably snowy picture with some ghosting. The aerial is a 4 dipole + reflector arrangement, A TV aerial, properly called a Yagi Array, only has one proper dipole (sometimes folded) this dipole is in fornt of the reflector and is where the signal is received. The other elements are properly called 'directors' and contribute to received power by both adding to the signal [Gain] AND making the beam more narrow [Beam width] - requiring 'better' pointing. Four dipoles plus reflector - three directors(?) doesn't seem at first glance to be very directional - glancing out of my window at neighbouring yagi arrays I count seven directors poiting at a transmitter in visual range on top of a hill perhaps six miles away. Three directors might indicate a low gain wide beamwidth array. Nope - I guess this is a form of 'curtain' array - four little 'bow-tie' elements sitting in front of a mesh reflector. All 'fitted' in the loft by the expedient of nailing the reflector to a roof-joist (!) - although the installer did use a signal-strength meter to set it up.... ............ that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... A high gain amplifier will increase the noise just as much as the signal and may swamp the input stages of your receivers. It's the wrong way round _ I'd say an oirish way - but that's probably banned by some legislation or other ; so I won't_. You need to have a good signal off the dipole. I thought as much - but thanks for confirming that I'm on the right track... To be fair - they did say that if we weren't happy then they'd come back & fit the aerial outside... It's _may_ not be the inide/outside aspectthat's wrong but the GAIN/BEAMWIDTH that's incorrectly supplied. BTW, with direct line-of-sight there's perhaps multiple paths for the signal to reach you You haven't mentioned the juxtapositioning of the 'enormous' steel to the yagi; nor the orientation of the steel to the transmitter (aligned/broadside on/ skewed. Perhaps the signal is bouncing off and your device is 'receiving' a back-lobe? The house is pretty much 'gable on' to the transmitter - so the aerial is looking through the end gable wall, a small internal wall, and 'along' the line of the big metal beam. Plenty of room for relections / multiple signal paths there ! I haven't been able to sight "Ballydehob " on Google Earth's site! 'Ballydehob' isn't the Gaelic for "valley of no signal" is it? So I don't know where abouts you are in relationship to Mount Gabriel - {Truthfully; I don't now where that is either! Do you ever get trumpet blasts?} We're pretty much due East of Gabriel. Ballydehob is to be found along the N71 from Skibbereen to Schull - about 1.5 hours drive west of Cork city... An Irish outfit that claims some expertise in terrestial Television - it probalby says so on their vans :- recommends:- NEW UHF TRANSMITTER ON AIR AT MOUNT GABRIEL, CO CORK That's the one ! RTE 1 NETWORK 2 TG4 Channel 29 Channel 33 Channel 23 Correct For best reception for viewers, a UHF Group A or broadband aerial should be used. For the east and south, aerials should be horizontally polarised. That'd be us then For the north and west, aerials should be vertically polarised. So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... There are _no_ 'good euro' .... There are when they are buying petrol at 2/3 the UK price over here ! g Thanks Adrian |
#13
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
Hi Andy
On Mon, 16 Oct 2006 19:15:37 +0100, Andy Hall wrote: On 2006-10-16 18:28:10 +0100, Adrian said: HI Andy Basically the dish isn't large enough. Signal strength needs to be higher, but more importantly the signal quality. My thoughts entirely Why would they fit a 'too small' dish ? Seems to be asking for trouble Perhaps this is what the distributor had in stock and told them it was OK. Ooh you cynic ! g It may be possible to make *some* improvement with a better quality LNB on the dish but this is usually a second order thing. The same 'expert installers' ( it says so on their van !) fitted an aerial for Terrestrial Irish TV. We are about 5 miles direct line of sight from the transmitter at Mount Gabriel - and getting a noticeably snowy picture with some ghosting. The aerial is a 4 dipole + reflector arrangement, that they've fitted in the loft (where it has to look through two concrete walls and is about 1ft from an enormous steel 'I-beam' which forms the ridge of the house. To compensate for this, they've added a high-gain amplifier.... This is pointless. Adding an amplifier when the signal is poor adds noise as well and doesn;t improve multipath reception. Thanks - you're confirming my suspicions g - wanted to be sure before tackilng them... To be fair - they did say that if we weren't happy then they'd come back & fit the aerial outside... I think you should ask them to do that, to be sure. g To be sure g So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... It should have gone outside in the first place, I guess the only thing in their defence was that it was pouring down at the time - but, working in the Emerald Isle you tend to expect that! You would. Also, as you've discovered, satellite signal strength drops when it's raining. Yes - understood However, it's really the error rate that counts. Agreed - that'd be the 'quality' reading on the setup screen ? The other thing to do before they come back is to take a look at this site http://www.lyngsat.com/packages/skyuk.html For the satellite bands used by Sky, (and many others), there are two bands (high and low) and vertically and horizontally polarised signals. When you select the program you want to watch on the receiver, it sends appropriate control signals up the cable to the LNB at the dish to select which of the 4 permutations should be used - it as actually the LNB that does the band and polarisation selection. What I would recommend is to choose a program at the bottom, middle and top of each band and of each polarisation (i.e. 12 programs altogether). Note them down with the Sky channel numbers. Then when the installers come back, try them all out and make sure they are OK, ideally when it's raining. If all of this works reliably, then you can be reasonably confident that all channels will. Fairy nuff - will do some homework - thanks ! Adrian |
#14
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
Adrain,
Some local practicalities, I suggest that you go to Skib, over the bridge past the hotel, turn left and on the left-hand-side about 50 metres on is a v small TV shop. Not very impressive but they are SKY agents, they service trawler radios, are radio enthusiasts and really understand both the basics of satellite and terrestrial. There are two sons of the fierce older lady, one does TV stuff and the other real radio. I addition, they understand the special problems of the area, bounce off Gabriel, just how low the satellites are, etc. They have sorted my sat-TV a couple of times after the gales displaced dishes. I have discussed the physics of it all and I am certain that they know their stuff. Bite the bullet, spend a few Euros and get the local experts. Oh, I think the bigger firm "T" in the centre of Skib much more "impressive" but may not be as good, lots of lads and flash. I'll be in Ballydehob next week and when I remember the name of the excellent Skib TV folks, I'll put them on this discussion. I really do think that local experts (I do mean experts) will be a better bet than abstract advice from folks who have not had to set up aerials in W Cork. (9deg West). EP PS... Although from the furthest West in Europe and a tad remote, the folks I have recommended were trained in good Technical Colleges and go to all the update events in London etc. Have alook at the quality and orice of their HD stuff in their quaint little shop |
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
On 2006-10-16 20:46:59 +0100, Adrian said:
I did take a look in the loft, and the joints between the dish coax and the downlead in the walls are simply 'wrapped & insulating tape' - maybe there's a cock-up there ?? \ Ah.... They've used cable that was in the wall? There is a pretty good chance that this is TV coax. This cable is basically ****e and is marginal for UHF TV which has a frequency range up to about 900MHz. The frequencies used between LNBs and receivers go to around twice that and the effect will be signal loss and possibly cable reflections etc. The LNB cable should be CT100 and it should be home run all the way to the receiver. |
#16
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
On 2006-10-16 20:50:33 +0100, Adrian said:
Hi Andy On Mon, 16 Oct 2006 19:15:37 +0100, Andy Hall wrote: On 2006-10-16 18:28:10 +0100, Adrian said: HI Andy Basically the dish isn't large enough. Signal strength needs to be higher, but more importantly the signal quality. My thoughts entirely Why would they fit a 'too small' dish ? Seems to be asking for trouble Perhaps this is what the distributor had in stock and told them it was OK. Ooh you cynic ! g Wouldn't be the first time. Surely you've been to a plumbers merchants when the local trade are in there for the morning mothers meeting. I wouldn't expect a big difference..... However, it's really the error rate that counts. Agreed - that'd be the 'quality' reading on the setup screen ? Exactly. The other thing to do before they come back is to take a look at this site http://www.lyngsat.com/packages/skyuk.html For the satellite bands used by Sky, (and many others), there are two bands (high and low) and vertically and horizontally polarised signals. When you select the program you want to watch on the receiver, it sends appropriate control signals up the cable to the LNB at the dish to select which of the 4 permutations should be used - it as actually the LNB that does the band and polarisation selection. What I would recommend is to choose a program at the bottom, middle and top of each band and of each polarisation (i.e. 12 programs altogether). Note them down with the Sky channel numbers. Then when the installers come back, try them all out and make sure they are OK, ideally when it's raining. If all of this works reliably, then you can be reasonably confident that all channels will. Fairy nuff - will do some homework - thanks ! I hadn't spotted that you had a Sky+ box. That doesn't really make a difference to the above. Effectively there are two or possibly 4 independent LNBs in one at the dish. Adrian |
#17
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
HI Andy
On Mon, 16 Oct 2006 23:00:15 +0100, Andy Hall wrote: On 2006-10-16 20:46:59 +0100, Adrian said: I did take a look in the loft, and the joints between the dish coax and the downlead in the walls are simply 'wrapped & insulating tape' - maybe there's a cock-up there ?? \ Ah.... They've used cable that was in the wall? Yup ! The electrician (bless him) did go to the trouble of installing a double aerial socket and a single side-by-side - so he was (maybe ?) thinking 'Sky+ and terrestrial'. I looked at the 'built-in' cable last night and couldn't see any info printed on it - it's got braid and foil screening, and is semi-airspaced (the white plastic 'honeycombe' effect) - but I couldn't see any maker's mark.... There is a pretty good chance that this is TV coax. This cable is basically ****e and is marginal for UHF TV which has a frequency range up to about 900MHz. The frequencies used between LNBs and receivers go to around twice that and the effect will be signal loss and possibly cable reflections etc. Hmmm ! I did double-check the signa; strengths etc on the skybox - last night both 'meters' were showing 50% strength, input 1 showed about 40% quality and 2 showed about 30%. Swapping the leads at the wall plate made not difference, also swapping the leads at the bcak of the skybox had no effect.... dunno what that proves ?? g The LNB cable should be CT100 and it should be home run all the way to the receiver. That'd be ideal, I agree... Must try to get up there and measure the size of the dish.... that might prove something.....? Thanks Adrian |
#18
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
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#19
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
The existing aerial's a sort of '4 dipoles and a single mesh
reflector' arrangement - not a Yagi Can you identify it? 95% of all TV aerials are Yagis. (And 95% of statistics are made up on the spot). Christian. |
#20
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
The LNB cable should be CT100 and it should be home run all the way to
the receiver. That'd be ideal, I agree... There are other cables that would be acceptable for this installation, like H109 or RG6 (provided it is indoors). Christian. |
#21
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
"Christian McArdle" wrote in message .. . The existing aerial's a sort of '4 dipoles and a single mesh reflector' arrangement - not a Yagi Can you identify it? 95% of all TV aerials are Yagis. (And 95% of statistics are made up on the spot). Christian. Chipping in, again, I can't quite parse what you're saying; is the aerial array; - query Case A: -- -- -- -- four off dipoles --------------------------- mesh reflector or;- Case B: -- -- -- four 'dipoles' = one dipole and three directors(?) -- ------------- mesh reflector /query In both Case A and Case B the transmitter is normal and on the 'dipole' side of the mesh. BTW, the 'mesh' (reflector) is theoretically infinitely large and stops all signals from behind ... luckily for us, the Lord ensured that the reflectors could be attacked with tin-snips and didn't need infinite dimensions; turns out that one only _needs_ the reflector to be this* big and the mesh only has to be this* far behind the dipoles [*this is a function of frequency] Case B would be normal and what RTE intend when they call for a UHF Band A aerial; CASE A is highly unusual - what RF Engineers describes as a phased array with 'intriguing' possibilities of gain, bandwidth and beamwidth as a function of frequency! -- Brian |
#22
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
On 2006-10-17 09:04:35 +0100, Adrian said:
HI Andy On Mon, 16 Oct 2006 23:00:15 +0100, Andy Hall wrote: On 2006-10-16 20:46:59 +0100, Adrian said: I did take a look in the loft, and the joints between the dish coax and the downlead in the walls are simply 'wrapped & insulating tape' - maybe there's a cock-up there ?? \ Ah.... They've used cable that was in the wall? Yup ! The electrician (bless him) did go to the trouble of installing a double aerial socket and a single side-by-side - so he was (maybe ?) thinking 'Sky+ and terrestrial'. I looked at the 'built-in' cable last night and couldn't see any info printed on it - it's got braid and foil screening, and is semi-airspaced (the white plastic 'honeycombe' effect) - but I couldn't see any maker's mark.... If there's foil it might be CT 100 but no guarantee. I would arrange for the whole thing to be done in known CT100 all the way then you know what you have. There is a pretty good chance that this is TV coax. This cable is basically ****e and is marginal for UHF TV which has a frequency range up to about 900MHz. The frequencies used between LNBs and receivers go to around twice that and the effect will be signal loss and possibly cable reflections etc. Hmmm ! I did double-check the signa; strengths etc on the skybox - last night both 'meters' were showing 50% strength, input 1 showed about 40% quality and 2 showed about 30%. Swapping the leads at the wall plate made not difference, also swapping the leads at the bcak of the skybox had no effect.... dunno what that proves ?? g That they are equal. The LNB cable should be CT100 and it should be home run all the way to the receiver. That'd be ideal, I agree... Must try to get up there and measure the size of the dish.... that might prove something.....? Probably that it;s too small. You would need to ask a known good local installer, but I would expect that a 90-100cm round dish with good LNB and CT100 cables all the way to the receiver would be the expectation. Thanks Adrian |
#23
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
Adrian
May I add that the people that I recommend also found it difficult to understand the losses between my dish and set. So they slung a good length of new "satelite" cable from the roof straight from the dish and in thru' the sitting-room window to by-pass the installed older co-ax. Lo and behold, v good signal/reception. So up into the roof space where the old cable ran. Mixtures of old coax with copper braid and better "satellite" cable with foil, jointed by twisting inners to inners and outers to outers with lots of insulating tape! Whole lot sorted and signal OK despite rain and locality. I understand that "T" did the job before but if they argue I'll withdraw, without reserve, after all folks in IE are v litigious :-) I am not impressed with posh vans with logos claiming excellence painted on the outside. Much better to work with an honest bloke who arrives in a beat-up old estate but knows the physics, 'cos he's an real specialist, trained but also a personal enthusiast. Have a look at the TVs in their shop, the serious folk deal with them despite it looking a tiny outfit. Adrian, this is getting to be something of a minority interest. If you want further chat, I suggest you send me a note to the address I gave you earlier this year when you announced your move to W Cork. For those who are finding this boring, I think there's a more general issue, it's really about a plea to use good, well-trained, honest folks who need a fair day's pay rather that the big Co. with lots of adverts who employ lads who can just about do a SKY instal on a S facing house and not much more. I think this applies to quite a lot of DIY... honest folks, trained, competent and keen, earning a fair return and sod the cowboys. EP EP |
#24
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
HI Brian / Andy
On Tue, 17 Oct 2006 08:38:09 GMT, "Brian Sharrock" wrote: "Christian McArdle" wrote in message . .. The existing aerial's a sort of '4 dipoles and a single mesh reflector' arrangement - not a Yagi Can you identify it? 95% of all TV aerials are Yagis. (And 95% of statistics are made up on the spot). Christian. Chipping in, again, I can't quite parse what you're saying; is the aerial array; - query Case A: -- -- -- -- four off dipoles --------------------------- mesh reflector Yes - that's the one ! or;- Case B: -- -- -- four 'dipoles' = one dipole and three directors(?) -- ------------- mesh reflector /query No - no directors, just cunningly-phased dipoles and a mesh reflector. Low-gain, wide-angle - methinks In both Case A and Case B the transmitter is normal and on the 'dipole' side of the mesh. BTW, the 'mesh' (reflector) is theoretically infinitely large and stops all signals from behind ... luckily for us, the Lord ensured that the reflectors could be attacked with tin-snips and didn't need infinite dimensions; turns out that one only _needs_ the reflector to be this* big and the mesh only has to be this* far behind the dipoles [*this is a function of frequency] Case B would be normal and what RTE intend when they call for a UHF Band A aerial; CASE A is highly unusual - what RF Engineers describes as a phased array with 'intriguing' possibilities of gain, bandwidth and beamwidth as a function of frequency! Even better if the mesh is electrically connected to the gurt big I-beam (by virtue of being physically in contact with it ! Had a quick discussion with the installers today and suggested that I might be interested in paying their bill if they might be interested in coming back and doing a proper installation... ...we'll see....g Thanks Adrian |
#25
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
"Adrian" wrote in message ... HI Brian / Andy On Tue, 17 Oct 2006 08:38:09 GMT, "Brian Sharrock" wrote: "Christian McArdle" wrote in message ... The existing aerial's a sort of '4 dipoles and a single mesh reflector' arrangement - not a Yagi Can you identify it? 95% of all TV aerials are Yagis. (And 95% of statistics are made up on the spot). Christian. Chipping in, again, I can't quite parse what you're saying; is the aerial array; - query Case A: -- -- -- -- four off dipoles --------------------------- mesh reflector Yes - that's the one ! or;- Case B: snip Let that be a lesson to me; I assumed that it must be a Yagi. After all, that's what _everybody_ uses. I re-read your ' ... not a Yagi' and thought; - "No! they couldn't use that type ... could they?" Case B would be normal and what RTE intend when they call for a UHF Band A aerial; CASE A is highly unusual - what RF Engineers describes as a phased array with 'intriguing' possibilities of gain, bandwidth and beamwidth as a function of frequency! Even better if the mesh is electrically connected to the gurt big I-beam (by virtue of being physically in contact with it ! The groundng effect of a lump of steel shouldn't hurt it too much. 'Theoreticaaly' the reflector is the minimum area that one can 'get away with' . Additional material, provided it's behind the dipoles, shouldn't matter. RF energy is what 'we' call 'funny stuff' (another technical term ) bits of cable, such as co-ax, that seem to be normally resitsive become 'open circuit' and/or 'dead short circuit' at different points along the cable once one starts trying to stuff rf energy along it: technically it's all to do with lambda and halve and quarters but as lambda changes with frequency it all get too hard for humnas to suss out. { partly becaue it's all tto hard to imagine 'receiving' things off an aerial - we utilise the theory of reciprocity and pretend that the aerial is a transmitter } Your Irish installers seem to have attempted to install a phased array, wherein one dipole will 'interfere' with it's adjacent neighbour cauisng nulls and maxima to overlap creating a narrowing of the beam without significantly increasing the received signal . Adding these four signals together in such a manner that they sum accumulatively and not destructively is a non-trivial task. Attempting to transmit such a signal down a non-homogenous cable to a receiver is another minefield. Reflections at junctions and terminations at cable end will almost invariabley caue a 'Standing Wave' to be generated, and Sod's Law [may be known as Murphy's Law in the Republic] will almost guarantee that you may have an minima at the end. Had a quick discussion with the installers today and suggested that I might be interested in paying their bill if they might be interested in coming back and doing a proper installation... ..we'll see....g Thanks Adrian Now to find out if there's any 'good euro' -- Brian |
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
Adrian, this is getting to be something of a minority interest. If you
want further chat, I suggest you send me a note to the address I gave you earlier this year when you announced your move to W Cork. There's no need to switch to email if the subject is still on topic and doesn't involve personal details. If people are bored, they can ignore the thread. Christian. |
#27
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
The groundng effect of a lump of steel shouldn't hurt it too much.
'Theoreticaaly' the reflector is the minimum area that one can 'get away with' . Not that simple, depends on what directional characteristics you want.. Additional material, provided it's behind the dipoles, shouldn't matter. RF energy is what 'we' call 'funny stuff' Thats because its a bit difficult to understand, theres nothing "funny" about it!... (another technical term ) bits of cable, such as co-ax, that seem to be normally resitsive become 'open circuit' and/or 'dead short circuit' at different points along the cable once one starts trying to stuff rf energy along it: technically it's all to do with lambda and halve and quarters but as lambda changes with frequency it all get too hard for humnas to suss out. { partly becaue it's all tto hard to imagine 'receiving' things off an aerial - we utilise the theory of reciprocity and pretend that the aerial is a transmitter } Good idea Your Irish installers seem to have attempted to install a phased array, wherein one dipole will 'interfere' with it's adjacent neighbour cauisng nulls and maxima to overlap creating a narrowing of the beam without significantly increasing the received signal . Adding these four signals together in such a manner that they sum accumulatively and not destructively is a non-trivial task. Attempting to transmit such a signal down a non-homogenous cable to a receiver is another minefield. Reflections at junctions and terminations at cable end will almost invariabley caue a 'Standing Wave' to be generated, and Sod's Law [may be known as Murphy's Law in the Republic] I thought he was a Yank?.. will almost guarantee that you may have an minima at the end. Had a quick discussion with the installers today and suggested that I might be interested in paying their bill if they might be interested in coming back and doing a proper installation... ..we'll see....g Thanks Adrian Now to find out if there's any 'good euro' -- Tony Sayer |
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
Brian Sharrock wrote: "Adrian" wrote in message ... [...] Let that be a lesson to me; I assumed that it must be a Yagi. After all, that's what _everybody_ uses. I re-read your ' ... not a Yagi' and thought; - "No! they couldn't use that type ... could they?" [...] The groundng effect of a lump of steel shouldn't hurt it too much. 'Theoreticaaly' the reflector is the minimum area that one can 'get away with' . Additional material, provided it's behind the dipoles, shouldn't matter. RF energy is what 'we' call 'funny stuff' (another technical term ) bits of cable, such as co-ax, that seem to be normally resitsive become 'open circuit' and/or 'dead short circuit' at different points along the cable once one starts trying to stuff rf energy along it: technically it's all to do with lambda and halve and quarters but as lambda changes with frequency it all get too hard for humnas to suss out. { partly becaue it's all tto hard to imagine 'receiving' things off an aerial - we utilise the theory of reciprocity and pretend that the aerial is a transmitter } Your Irish installers seem to have attempted to install a phased array, wherein one dipole will 'interfere' with it's adjacent neighbour cauisng nulls and maxima to overlap creating a narrowing of the beam without significantly increasing the received signal . [...] Maybe this has been clarified earlier in the thread ... It seems likely to me that the OP's aerial is a 'stacked dipole array' as shown in Fi.g 5 of: http://www.wrightsaerials.tv/digitalterrtvrecep.htm. They used to be marketed under the product name 'Colour King' (I've forgotten the maker). I have seen them on relatively new houses here in the Donegal area --- which is hilly and has otherwise marginal reception from across the national border. But, as someone speculated, it could be that they are used because they happen to be surplus stock. They used to be used a lot in Ireland for 'extremely long distance reception' (my term), e.g. receiving BBC, ITV in the Irish midlands --- order of 50-70 miles from the transmitter in the Mournes. You would see them atop gynormously high masts. Incidentally, compared to what went before (huge Yagi-like arrays --- Hirschmann brand --- that weighed a ton), they seemed to be machanically less fragile and offered less wind cross-section. After the stacked dipole array, the same areas switched to what appeared to be a single dipole design, with a dish shaped mesh reflector. Now, of course, everyone in those regions use satellite or cable. (Regarding terrestial reception.) If the OP is in a flatish area, then find a neighbour with good reception and do as they do --- same aerial type, some band (colour coded?), same polarisation. It could be that you can experiment with aerial mounted on something easily reachable from the ground; five miles from the transmitter was mentioned, I think. If you are in a very undulating area, then all bets are off. As others have noted, skilled aerial installers may be hard to find; for that reason alone, you should be prepared to pay decently for a decent job done, and a job that will last. Installing an aerial on a chimney is easily d.i.y. But you may not have ladders and a head for heights. Best regards, Jon C. |
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
On Mon, 16 Oct 2006 18:31:52 +0100, Adrian wrote:
Bigger dish required!. See also http://www.astra2d.co.uk Not a useful URL that... Does a 'too small' dish explain why there's the difference in signal strength between the two channels ? By the the "two channels" I take it you mean the two independant ouputs from the LNB. They should be pretty much the same. I suspect your professional cowboys haven't aligned the thing properly, did they use a signal meter of some sort to do the alignment? http://www.brittany-satellites.com/astra_footprint.php Shows the footprint for the various beams. IMHO a properly aligned Zone 1 (the smaller of the two) minidish should be fine, Zone 2 would be better. -- Cheers Dave. pam is missing e-mail |
#30
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
In article om, Dave
Liquorice writes On Mon, 16 Oct 2006 18:31:52 +0100, Adrian wrote: Bigger dish required!. See also http://www.astra2d.co.uk Not a useful URL that... Oh dear! seems its gone tits up, was a very useful site with reports of Sky reception all over Europe.. Perhaps sky got them to take it down?.. Does a 'too small' dish explain why there's the difference in signal strength between the two channels ? By the the "two channels" I take it you mean the two independant ouputs from the LNB. They should be pretty much the same. I suspect your professional cowboys haven't aligned the thing properly, did they use a signal meter of some sort to do the alignment? http://www.brittany-satellites.com/astra_footprint.php Shows the footprint for the various beams. IMHO a properly aligned Zone 1 (the smaller of the two) minidish should be fine, Zone 2 would be better. Very much so... -- Tony Sayer |
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Adrian saying something like: So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... puff, pant Sorry for the delay, got here as fast as I could. Right, the sat dish. **** the Sky dish, you need a min of 90cm and preferably a 1M dish. Sorted. As far as the aerials go; if you're in an area where all the Irish channels are on UHF, then you need an outside antenna of the appropriate channel group. If RTE1 and 2 are still on VHF in your area, you need a box section VHF antenna (it's 2 dipoles and a square reflector) and a UHF one for the other channels (TV3, TG4, C6) and you simply combine them into one at the masthead. Easy. -- Dave |
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Adrian saying something like: I did take a look in the loft, and the joints between the dish coax and the downlead in the walls are simply 'wrapped & insulating tape' - maybe there's a cock-up there ?? Fuicking hell. You've encountered the Untrained Clowns Satellite Installation Company. They've got branches all over the place. -- Dave |
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Adrian saying something like: Why would they fit a 'too small' dish ? Seems to be asking for trouble Perhaps this is what the distributor had in stock and told them it was OK. Ooh you cynic ! g Not too much - the recommended dish for most of Ireland is around 80cm, but it's inadequate. Much, much better to simply get a 1M dish in the first place. -- Dave |
#34
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Dave Liquorice" saying something like: http://www.brittany-satellites.com/astra_footprint.php Shows the footprint for the various beams. IMHO a properly aligned Zone 1 (the smaller of the two) minidish should be fine, Zone 2 would be better. Utter crap. -- Dave |
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
Hi Dave
On Fri, 20 Oct 2006 01:03:36 +0100, Grimly Curmudgeon wrote: We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Adrian saying something like: I did take a look in the loft, and the joints between the dish coax and the downlead in the walls are simply 'wrapped & insulating tape' - maybe there's a cock-up there ?? Fuicking hell. You've encountered the Untrained Clowns Satellite Installation Company. They've got branches all over the place. g Yes - a truly universal organisation. I queried the 'twist-it-together' approach with the shop manager on the phone - he didn't seem at all concerned - 'Ah no - that's how we always do it'...... Still waiting for them to come back for a sceond attempt.. I'll keep you all updated ! Adrian |
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
Hi again Dave
On Fri, 20 Oct 2006 01:09:16 +0100, Grimly Curmudgeon wrote: We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Adrian saying something like: Why would they fit a 'too small' dish ? Seems to be asking for trouble Perhaps this is what the distributor had in stock and told them it was OK. Ooh you cynic ! g Not too much - the recommended dish for most of Ireland is around 80cm, but it's inadequate. Much, much better to simply get a 1M dish in the first place. Which I think was the advice I was given when I first asked the question here a couple of months ago... Can't decide an easy 'exit strategy' from these cowboys. Sorely tempted to dismantle their handywork and take it back to them in a big cardboard box ! Trouble is - the dish is up on the end gable, and it's a bit higher than I'm happy with, without using a roof ladder.... ....but I'm tempted g 'Spose I could ask the 'other expert' do do an install for me and to take their stuff down at the same time g Regards Adrian |
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
Hi Dave
On Fri, 20 Oct 2006 00:20:52 +0100, Grimly Curmudgeon wrote: We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Adrian saying something like: So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... puff, pant Sorry for the delay, got here as fast as I could No problem !. Right, the sat dish. **** the Sky dish, Might be a bit of a problem - it's up high & I'm not good on ladders... and it's raining g you need a min of 90cm and preferably a 1M dish. Sorted. Oh - I see what you mean..... gg - sounds right.... As far as the aerials go; if you're in an area where all the Irish channels are on UHF, then you need an outside antenna of the appropriate channel group. I'm sure it's UHF - and the antenna they've supplied claims to be wideband - just needs to be outside, I think.. If RTE1 and 2 are still on VHF in your area, you need a box section VHF antenna (it's 2 dipoles and a square reflector) and a UHF one for the other channels (TV3, TG4, C6) and you simply combine them into one at the masthead. Easy. ...When you know how..... ! Thanks for the advice Adrian |
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
On Fri, 20 Oct 2006 01:14:50 +0100, Grimly Curmudgeon wrote:
http://www.brittany-satellites.com/astra_footprint.php Shows the footprint for the various beams. IMHO a properly aligned Zone 1 (the smaller of the two) minidish should be fine, Zone 2 would be better. Utter crap. So those coverage maps are crap are they? References for your assertion please. -- Cheers Dave. pam is missing e-mail |
#39
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
In article , Grimly
Curmudgeon writes We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Adrian saying something like: So - what should I expect in terms of satellite 'reliability' and terrestrial picture quality?? - given that we are somewhat 'out in the sticks - I don't want to be unreasonable with them, but I also don;'t want to pay good euro for a 2nd-class job... puff, pant Sorry for the delay, got here as fast as I could. Right, the sat dish. **** the Sky dish, you need a min of 90cm and preferably a 1M dish. Sorted. As far as the aerials go; if you're in an area where all the Irish channels are on UHF, then you need an outside antenna of the appropriate channel group. If RTE1 and 2 are still on VHF in your area, you need a box section VHF antenna (it's 2 dipoles and a square reflector) What's wrong with a simple multi element Yagi array For Band three then?... and a UHF one for the other channels (TV3, TG4, C6) and you simply combine them into one at the masthead. Easy. -- Tony Sayer |
#40
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A Bit OT - Satellite & Terrestrial TV in West Cork, Ireland
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Dave Liquorice" saying something like: On Fri, 20 Oct 2006 01:14:50 +0100, Grimly Curmudgeon wrote: http://www.brittany-satellites.com/astra_footprint.php Shows the footprint for the various beams. IMHO a properly aligned Zone 1 (the smaller of the two) minidish should be fine, Zone 2 would be better. Utter crap. So those coverage maps are crap are they? References for your assertion please. Personal experience - that do you? -- Dave |
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