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How to improve this aerial? Replace or move higher?
Recently our TV reception has detriorated markedly, we live near
Woodbridge and get our signals from Sudbury so we're getting on for "fringe area". The Woodbridge relays don't do anything for us. Until recently reception was pretty good most of the time with the very occasional drop out and sometimes a 'bad day' with odd atmospheric conditions. I can't see anything obvious that has changed (like failed connectors) so I suspect that we may be being affected by particularly lush growth at the tops of some trees which are probably somewhat on our path towards Sudbury. Analogue reception has become pretty ropey too as well so I think it's aerial (or downlead) rather than anytthing else. So - what to do? The current aerial is a cheap "high gain" one, here are a couple of pictures ot it:- http://www.isbd.net/images/DSCF0812.JPG http://www.isbd.net/images/DSCF0813.JPG (Sorry they're so dark, it was a very dull day, still gives an idea of what's there) It's difficult to make the aerial a *lot* higher where it is but there is actually another roof where I have *much* better access and could mount it higher, the only disadvantage there is that it's relatively remote from the TVs (on a separate building). So would I be better off with a better aerial or would it be better to move it to a better location? Can one get wireless connections for a TV aerial? If a better aerial seems a good idea what would be recommended? I think we genuinely do need "wide band" for the Sudbury transmitter. (In the longer term the trees may be coming down but that's months ahead and I want to improve things before then, even if it is the trees) -- Chris Green |
How to improve this aerial? Replace or move higher?
wrote in message ... Recently our TV reception has detriorated markedly, we live near Woodbridge and get our signals from Sudbury so we're getting on for "fringe area". The Woodbridge relays don't do anything for us. Until recently reception was pretty good most of the time with the very occasional drop out and sometimes a 'bad day' with odd atmospheric conditions. I can't see anything obvious that has changed (like failed connectors) so I suspect that we may be being affected by particularly lush growth at the tops of some trees which are probably somewhat on our path towards Sudbury. Analogue reception has become pretty ropey too as well so I think it's aerial (or downlead) rather than anytthing else. So - what to do? The current aerial is a cheap "high gain" one, here are a couple of pictures ot it:- http://www.isbd.net/images/DSCF0812.JPG http://www.isbd.net/images/DSCF0813.JPG (Sorry they're so dark, it was a very dull day, still gives an idea of what's there) It's difficult to make the aerial a *lot* higher where it is but there is actually another roof where I have *much* better access and could mount it higher, the only disadvantage there is that it's relatively remote from the TVs (on a separate building). So would I be better off with a better aerial or would it be better to move it to a better location? Can one get wireless connections for a TV aerial? If a better aerial seems a good idea what would be recommended? I think we genuinely do need "wide band" for the Sudbury transmitter. (In the longer term the trees may be coming down but that's months ahead and I want to improve things before then, even if it is the trees) Why has the aerial been bolted on upside down?.. you may just as well have clamped the boom directly to the mast. -- Chris Green |
How to improve this aerial? Replace or move higher?
Ivan wrote:
wrote in message ... So - what to do? The current aerial is a cheap "high gain" one, here are a couple of pictures ot it:- http://www.isbd.net/images/DSCF0812.JPG http://www.isbd.net/images/DSCF0813.JPG [snip] Why has the aerial been bolted on upside down?.. you may just as well have clamped the boom directly to the mast. I have no idea, maybe there was nothing telling which way was "the right way up". It's not going to have a significant effect on the performance anyway is it? (Except the loss of a few inches of height) -- Chris Green |
How to improve this aerial? Replace or move higher?
wrote in message ... Recently our TV reception has detriorated markedly, we live near Woodbridge and get our signals from Sudbury so we're getting on for "fringe area". The Woodbridge relays don't do anything for us. Until recently reception was pretty good most of the time with the very occasional drop out and sometimes a 'bad day' with odd atmospheric conditions. I can't see anything obvious that has changed (like failed connectors) so I suspect that we may be being affected by particularly lush growth at the tops of some trees which are probably somewhat on our path towards Sudbury. Analogue reception has become pretty ropey too as well so I think it's aerial (or downlead) rather than anytthing else. So - what to do? The current aerial is a cheap "high gain" one, here are a couple of pictures ot it:- http://www.isbd.net/images/DSCF0812.JPG http://www.isbd.net/images/DSCF0813.JPG (Sorry they're so dark, it was a very dull day, still gives an idea of what's there) It's difficult to make the aerial a *lot* higher where it is but there is actually another roof where I have *much* better access and could mount it higher, the only disadvantage there is that it's relatively remote from the TVs (on a separate building). So would I be better off with a better aerial or would it be better to move it to a better location? Can one get wireless connections for a TV aerial? If a better aerial seems a good idea what would be recommended? I think we genuinely do need "wide band" for the Sudbury transmitter. (In the longer term the trees may be coming down but that's months ahead and I want to improve things before then, even if it is the trees) Firstly mount it with the cradle the right way up and without the mast running through the elements - like the centre cradle mounted aerial here http://www.wrightsaerials.tv/aerialp...odern/021.html. The current method will cause signal attenuation. Replace the cable with copper on copper double screened co-ax (CT100, PF100 etc) keeping any joints to a minimum and using only F connector joints if possible. Consider adding a screened masthead amplifier. Consider replacing the aerial with a better quality one. For Sudbury a quality group E should be better than wideband, sadly they appear to be thin on the ground these days. Someone may be able to suggest one. Blake are showing an SR18E on their website http://www.blake-uk.com/page/aerial_benchmark/Aerial_SR |
How to improve this aerial? Replace or move higher?
I live just down the road at Felixstowe and have the same problem. Of
course, we are officially outside the Freeview coverage area. I fitted a DAT75, much to the derision of all the old hands here, but when I challenged them to find me a wideband aerial (necessary for Sudbury, as you say) with a better front-to-back ratio they all went quiet. Including the always helpful Bill. The reason for the highest possible front/back ratio is that our reception is comprehensively buggered by picking up stuff from the continent on the back of the aerial. In "nice" weather like this the problem is usually much worse (I don't know much about propagation, but someone here will explain it). The DAT75 is big and ugly, but so far is the only aerial to provide Freeview reception with any kind of reliability where I live. Even so, in high pressure atmospheric conditions I lose Virgin 1, followed by the ITV channels. The signal strength remains the same, but the "quality" reading falls right away, confirming that the incoming signal from Sudbury is probably being corrupted by "noise" off the back of the aerial. So far the rest of the channels have held out perfectly. To be perfectly honest, I would be sorely tempted to give it up and go for Freesat. The big problem right now is the lack of any decent Freesat PVRs, but in a year's time they should be pretty well sorted. Freeview should leap into life in our area in 2011, but that's too long to wait, isn't it? One of Bill's colleagues has done some interesting tests on a number of aerials and has found one which comprehensively outperforms the DAT75 in terms of forward gain, at least. What the front to back ratio is like I don't know, but it might be worth a look. Bill, could you remind us of that website? (Sorry, I've lost it again). Thanks, SteveT |
How to improve this aerial? Replace or move higher?
On Wed, 23 Jul 2008 17:24:21 +0100, "Ivan"
wrote: wrote in message . .. Recently our TV reception has detriorated markedly, we live near Woodbridge and get our signals from Sudbury so we're getting on for "fringe area". The Woodbridge relays don't do anything for us. Until recently reception was pretty good most of the time with the very occasional drop out and sometimes a 'bad day' with odd atmospheric conditions. I can't see anything obvious that has changed (like failed connectors) so I suspect that we may be being affected by particularly lush growth at the tops of some trees which are probably somewhat on our path towards Sudbury. Analogue reception has become pretty ropey too as well so I think it's aerial (or downlead) rather than anytthing else. So - what to do? The current aerial is a cheap "high gain" one, here are a couple of pictures ot it:- http://www.isbd.net/images/DSCF0812.JPG http://www.isbd.net/images/DSCF0813.JPG (Sorry they're so dark, it was a very dull day, still gives an idea of what's there) It's difficult to make the aerial a *lot* higher where it is but there is actually another roof where I have *much* better access and could mount it higher, the only disadvantage there is that it's relatively remote from the TVs (on a separate building). So would I be better off with a better aerial or would it be better to move it to a better location? Can one get wireless connections for a TV aerial? If a better aerial seems a good idea what would be recommended? I think we genuinely do need "wide band" for the Sudbury transmitter. (In the longer term the trees may be coming down but that's months ahead and I want to improve things before then, even if it is the trees) Why has the aerial been bolted on upside down?.. you may just as well have clamped the boom directly to the mast. -- Chris Green Maybe it's worked loose and fell that way? Anyway, I'd say that's your problem. Get the aerial mounted so the mast doesn't cut through the elements & you'll be fine. Marky P. |
How to improve this aerial? Replace or move higher?
Doctor D wrote:
Firstly mount it with the cradle the right way up and without the mast running through the elements - like the centre cradle mounted aerial here http://www.wrightsaerials.tv/aerialp...odern/021.html. Ah, thank you, a picture is worth a thousand words (in this case anyway). The current method will cause signal attenuation. Replace the cable with copper on copper double screened co-ax (CT100, PF100 etc) keeping any joints to a minimum and using only F connector joints if possible. It already has good cable. Consider adding a screened masthead amplifier. There's an amplifier pretty close to it, it's probably only two or three metres from the aerial. Consider replacing the aerial with a better quality one. For Sudbury a quality group E should be better than wideband, sadly they appear to be thin on the ground these days. Someone may be able to suggest one. Blake are showing an SR18E on their website http://www.blake-uk.com/page/aerial_benchmark/Aerial_SR Thanks, that's the other sort of advice I was after. You're right, group E is better than wideband (I took a look at the Wolfbane site after my original post). -- Chris Green |
How to improve this aerial? Replace or move higher?
"Steve Thackery" wrote in message ... I fitted a DAT75, much to the derision of all the old hands here, but when I challenged them to find me a wideband aerial (necessary for Sudbury, as you say) with a better front-to-back ratio they all went quiet. Including the always helpful Bill. I think pretty well any of the very large high gain wideband aerials will have similar f/b ratios to the DAT75, and some of these will also have the advantage that they remain intact for many years. The only major performance difference between any of the 'good' makes of comparable aerial is how much they fiddle the figures that they give out. There's a natural performance limit to yagis, and the 'good' aerials are all nudging it. If one make is a bit better in one respect, it will be a bit worse in another. One of Bill's colleagues has done some interesting tests on a number of aerials and has found one which comprehensively outperforms the DAT75 in terms of forward gain, at least. What the front to back ratio is like I don't know, but it might be worth a look. Bill, could you remind us of that website? (Sorry, I've lost it again). Google for ATV Sheffield. Bill |
How to improve this aerial? Replace or move higher?
wrote in message ... Recently our TV reception has detriorated markedly, we live near Woodbridge and get our signals from Sudbury so we're getting on for "fringe area". The Woodbridge relays don't do anything for us. Until recently reception was pretty good most of the time with the very occasional drop out and sometimes a 'bad day' with odd atmospheric conditions. I can't see anything obvious that has changed (like failed connectors) so I suspect that we may be being affected by particularly lush growth at the tops of some trees which are probably somewhat on our path towards Sudbury. Analogue reception has become pretty ropey too as well so I think it's aerial (or downlead) rather than anytthing else. So - what to do? The current aerial is a cheap "high gain" one, here are a couple of pictures ot it:- http://www.isbd.net/images/DSCF0812.JPG http://www.isbd.net/images/DSCF0813.JPG Leaving aside the obvious deficiencies of the aerial the important thing -- the biggest factor by far -- when tree screening is the problem, is the position of the aerial. You need to sweep the the area, trying every possible aerial location carefully. One metre can make a massive difference. On innumerable occasions (OK I lie, it's actually 1,345,602 occasions) I have done this and then simply moved the same aerial to a new location. The difference between one location and another with only a few feet between them can easily be 15dB. Generally the best spot for one channel will be the best for all of them. See my ancient piece on this subject: http://www.wrightsaerials.tv/resourc...-reception.pdf It creaks like the trees it talks about, but it's still basically valid. Bill |
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