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In article , David W.E. Roberts
writes "tony sayer" wrote in message ... http://www.chelsworth-lodge.nildram....NewAerials.jpg The chimney brackets are a bit close together and grip less of the pole than is ideal, but they are pretty hefty and feel very solid and secure. The pole grip compromise comes from two things. (1) There isn't that much chimney above the ridge to get wires around. (2) The aim is to get the TV aerial as high as possible to see over Felixstowe docks. The standoff for the FM aerial is also a compromise because the aerial comes with a wall/chimney mount so I had to source additional bits and pieces. However it is the suggested 1.5m away from the main pole, and pointing towards Manningtree. Why are you bothering to mount the FM folded dipole Vertical, is there anything around your area thats worth listening to thats vertical polarisation only then?.... Just following the instructions on the box :-) So what is best? Vertical, horizontal, sloping? Not sure what benefit I would get from mounting it in any other orientation unless the signals are e.g. horizontal only. Cheers Dave R All BBC main Tx's are Mixed these days (vertical and Horizontal polarisation) with IIRC the exception of some tinpot relay up in Scotland. No doubt some anorak will correct moi!. some interesting reading on that:) http://tx.mb21.co.uk/features/recognition/vhf-fm.asp http://tx.mb21.co.uk/gallery/wrotham/mixedpol.asp Most all ILR stations except some of the very small ones use Mixed as theres very little reason for putting the aerial Vertical except that end on to the aerial there will be a null as if you "looked" down as if you were some thousands of feet high over the aerial the pickup pattern is a figure of 8 shape so end on there won't be that much pickup. IIRC you were in Felixstowe so thats effectively up and down the coast and I don't think theres much of interest there and maybe not a lot from over the water;) So If I were U I'd mount it horizontally as its much less fuss and windload, especially on that mast you've got!.. -- Tony Sayer |
On Fri, 14 Jan 2005 20:49:40 -0000, David W.E. Roberts
wrote: Why are you bothering to mount the FM folded dipole Vertical, is there anything around your area thats worth listening to thats vertical polarisation only then?.... Just following the instructions on the box :-) So what is best? Vertical, horizontal, sloping? Not sure what benefit I would get from mounting it in any other orientation unless the signals are e.g. horizontal only. It's fine the way it is, David Arthur |
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In article , Kev
writes said the following on 14/01/2005 21:58: On 14 Jan, tony sayer wrote: All BBC main Tx's are Mixed these days (vertical and Horizontal polarisation) with IIRC the exception of some tinpot relay up in Scotland. No doubt some anorak will correct moi!. Actually that should have read Horiz ONLY;) The two nearest relays to me now (in England) are both vertical polarisation only. I'm sure there are others. As far as I'm aware there are no horizontal only relays. The following are Horizontal Only : Ardgour - BBC NR, BBC Scot BBC RnaG Pitlochry - BBC NR, BBC Scot Keswick Forest - BBC NR, BBC Cumbria Thats sounds like it/them The following are Vertical Only (The list is from March-2004 so some new Vertical only may have come on stream, and some may now be mixed) : 90 BBC National TXs Eh?, Which ones?.. Snipped a bit I was referring to BBC stations. Most all of those in your list are SALLIE licensees which are quite low power often 100 watts or less. And a lot of these have now been very generously allocated another 100 watts in the Horiz;) If the original poster is where I think he is theres virtually noting in that area Vertical only thats worth bothering to receive, and really that goes for a lot of the country IMHO. Most all ILR radio sounds rather poor over a good audio system due in the main to the tandem coding that creeps in these days and the processing that regretfully is set way too high;( Where I am in Cambridge I've got a four element Horizontal pol onto Madingley and I used to get Peterbourgh and hope to again one day;) apart from the BBC there is sufficient signal from the ILR's with the exception of Classic FM to receive them, but I can't say their that listenable;( -- Tony Sayer |
On Fri, 14 Jan 2005 21:54:03 -0000, Arthur wrote:
On Fri, 14 Jan 2005 20:49:40 -0000, David W.E. Roberts wrote: Why are you bothering to mount the FM folded dipole Vertical, is there anything around your area thats worth listening to thats vertical polarisation only then?.... Just following the instructions on the box :-) So what is best? Vertical, horizontal, sloping? Not sure what benefit I would get from mounting it in any other orientation unless the signals are e.g. horizontal only. It's fine the way it is, David Arthur It's a dipole, designed for omnidirectional reception & designed for mounting vertically. I would only mount it horizontally if I was trying to reject signals at 90 degrees to the desired Tx. The long stand-off pole is unneccesary, but if it gives no problems, leave it. Marky P. |
On 14 Jan 2005 11:02:19 -0800, "
wrote: BTW, why is not advisable to thread the co-ax inside the mast? On a straight mast longer than 1m the cable can slap against the inside of the mast. The noise will go down into the house via the building fabric. The solution is to attach cable ties loosely to the cable at 400mm intervals, leaving the surplus length of the ties in place. This is sptringy enough to hold the cable still inside the mast. Another useful tip from SUPER RIGGER! Bill The mast is cranked, so I would assume the cable is better supported slightly. Marky P. |
In article , Marky P
writes On Fri, 14 Jan 2005 21:54:03 -0000, Arthur wrote: On Fri, 14 Jan 2005 20:49:40 -0000, David W.E. Roberts wrote: Why are you bothering to mount the FM folded dipole Vertical, is there anything around your area thats worth listening to thats vertical polarisation only then?.... Just following the instructions on the box :-) So what is best? Vertical, horizontal, sloping? Not sure what benefit I would get from mounting it in any other orientation unless the signals are e.g. horizontal only. It's fine the way it is, David Arthur It's a dipole, designed for omnidirectional reception & designed for mounting vertically. I would only mount it horizontally if I was trying to reject signals at 90 degrees to the desired Tx. The long stand-off pole is unneccesary, but if it gives no problems, leave it. Marky P. A di-pole isn't designed for Vertical only at all. The directional pattern is set by the polarisation and mounting method. The real problem is when its mounted close to its support mast and the lack of a balun compounds the problem even further. I've modelled these with an aerial pattern designer and they ain't all that good when too close to a support structure. Having said that their much better than that "Halo" abortion!... I'd be a bit concerned with the windload on the original posters piccy;) -- Tony Sayer |
You missed out High Peak Radio, and that is VP only and I should know
cos I put the buggers up. Bill |
tony sayer said the following on 14/01/2005 23:00:
The following are Vertical Only (The list is from March-2004 so some new Vertical only may have come on stream, and some may now be mixed) : 90 BBC National TXs Eh?, Which ones?.. Cirencester Town SP023021 Clyro SO204432 Clettraval NF751716 Grantham SK905337 Deiniolen SH576621 Bowmore NR318590 Newbury SU494687 Nailsworth ST849990 Bexhill TQ744080 Rheola SN841061 Calne ST997699 Ness of Lewis NB533603 Llwyn-Onn SH625175 Westwood ST817598 Ullapool NH142935 Folkestone TR255389 Penmaen Rhos SH877779 Walsden South SD937215 Porth ST029919 Hebden Bridge SD988267 Kenley TQ329592 Blaenavon SO277063 Cwmafan SS798936 Idle SE163374 Plympton SX531555 Llangeinor SS905886 Berwick-upon-Tweed NT980547 Beacon Hill SX857620 Ben Gullipen NN598045 Luddenden SE048248 Chippenham ST914751 Penaligon Downs SX026683 Carnmoney Hill J336829 Crystal Palace TQ339712 Todmorden SD957241 Girvan NX211981 Membury SU307763 Keighley SE069444 Chard ST358086 Minehead SS966452 Abertillery SO224023 Croeserw SS858952 Blunsdon SU143900 Chesterfield SK383764 Bilsdale SE553962 Port Ellen NR338452 Bridport SY453915 Combe Martin SS582462 West Kilbride NS215483 Conwy SH781765 Egford Hill (Frome) ST764481 Chalford SO883017 Ogmore Vale SS929894 Crieff NN814200 Daliburgh NF736216 Rhymney SO127042 Holcombe Down SX934752 Newton NZ036653 Llandecwyn SH644371 Hutton ST361588 Darwen SD708223 Salcombe SX753398 Pennar ST209958 Axe Valley SY283945 Whalley SD729352 Ferndale ST006970 Llyswen SO137361 Gogwell SS967111 Rosemount NO203435 Whitehaven NX992127 Eyemouth NT947599 Caterham TQ343557 Barnoldswick SD897480 Cornholme SD918264 Mickleham TQ163538 Stranraer NX111632 Lyme Regis SY345935 Hemdean (Reading) SU710762 Beecroft Hill SE237350 Salisbury SU136285 Eitshal NB305302 Fenham NZ216648 Kingswear SX887511 Saddleworth SD987050 Ivybridge SX631538 Haslingden SD795236 Weymouth SY663779 Marlborough SU209688 Basingstoke SU643479 Woolmoor SE457881 I was referring to BBC stations. Most all of those in your list are SALLIE licensees which are quite low power often 100 watts or less. And a lot of these have now been very generously allocated another 100 watts in the Horiz;) As i said the list was from 10 months ago (Same reason High Peak is missing), quite possibly from month older OFCOM data too. Unless you are getting one of the three horizontal only BBC relays, need the directional gain or there is some specific reason why you need horizontal (i.e. at my former address BBC Sheffield 94.7 could only be recived with the aerial mounted horizontally in the loft, at an address before that BRMB was only listenable with the aerial horizontal due to the higher powered Trent FM) vertical would give you the largest number of stations wouldn't it? - espcially considering a number of Regionals (Galaxy 105, Real Radio 106-108) are much higher powered in the vertical plane than the horizontal. Not forgetting any RSL's that you might want to listen to. |
"tony sayer" wrote in message ... snip So If I were U I'd mount it horizontally as its much less fuss and windload, especially on that mast you've got!.. One thing still puzzles me - I can't see much difference in the wind loading if the dipole is horizontal or vertical. I presume that sideways on there would be some more loading when the dipole is vertical, and this would be enhanced by the long lever the dipole is mounted on, but given the relatively slim profile of the dipole when the wind is at right angles, is this going to be a major issue? Cheers Dave R |
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