Briantist:Box TV channels now available online - CMU Complete Music Update http://t.co/rgjyIdo0vy Briantist:Read this! You know you want to... is out! http://t.co/iZRMlAut0g ▸ Top stories today via @SEOSeanUK Briantist:Media Talk podcast Woolwich attack coverage and Boris ban lifted http://t.co/qe1Ag4afdQ yorkshirewander:RT @Briantist: New Google maps has some interesting bugs. you have to take a bus to get from Victoria Station to Victoria Station! http://t.co/I5bspH6UZR Briantist:Victoria Station #fail for new Google maps ... http://t.co/t7uCQruyDz Briantist:New Google maps has some interesting bugs. you have to take a bus to get from Victoria Station to Victoria Station! http://t.co/I5bspH6UZR mapperz:RT @Briantist: From the archive: Want to see where a point on a line of sight on a map? Click on UK Free TV! Here's another ... http://t.co/Mx19ptoKdb Briantist:From the archive: Want to see where a point on a line of sight on a map? Click on UK Free TV! Here's another ... http://t.co/Mx19ptoKdb Briantist:Now picks up Freesat advertising business - Advertising news - Campaign http://t.co/rSLGNsOWnZ Briantist:Read this! You know you want to... is out! http://t.co/iZRMlAut0g ▸ Top stories today via @TamworthH
By using much higher frequencies (gigahertz, compared to terrestrial televisions megahertz) more transmission channels called transponders (the satellite equivalent of multiplexes) can be provided. For example, there are only six Freeview multiplexes, but Sky or Freesat users can access two hundred satellite transponders.
Aside from exceptional weather conditions (very heavy rain for example) digital satellite provides stable pictures and audio. Where Freeview transmitters are no more than 732 metres above sea level, the geostationary satellites used for television are 35,800,000 metres above the equator so reception is possible even where buildings, trees and hills make terrestrial reception impossible.
The downside of the transmitters being 22,300 miles up in the air is that the signals are very, very weak - so standard TV aerial is of little use. When the signals are sent to the satellites, huge dish transmitters are used to uplink the signal to the satellite. These are tens of metres from side to side, and feature an emitter that generates the signal, which is first bounced of a mirror (called a reflector) and then off the surface of the parabolic dish.
There are many satellites in the sky over the equator. Often these are in clusters over a particular position, for example there are four used for UK television are at 28.2 degrees east. There is another cluster over the 19.2 degrees east positions that are used for German television.
To receive these very weak signals from the satellite, it is necessary to use a dish for reception too. By using a reflective dish, this concentrates the signals onto a small device called a LNB. This is held in front of the dish by a metal arm.
The size of dish for reception is typically much smaller; often 60cm to 100cm in diameter, but the exact size depends upon the transmitting satellite transponder. To keep the transmission power levels down to levels that can be powered by the satellite's solar panels, each beam is focused on a particular area of the Earth's surface. If you are trying to receive the signal at the centre of this zone, a small dish is required. At the outer edges, you may need a 5 metre dish. Maps of these zones are provided by the satellite companies, and are called satellite footprints.
When the dish is installed it must be aligned carefully as the signal is very weak. The installer needs to know the inclination and the azimuth from the ground location to the satellite. If you install yourself you will find that there are markings on the dish that are used to point the dish in the correct position. It is important that the view of the satellite will not be blocked, so must take into account leaves growing on trees and potential building works.
For many people the LNB will have a single cable connected to it, however if you have Sky+ or a multi-room installation the LNB package will actually contain four receivers a quad-LNB. Unlike terrestrial television where you can split the aerial cable to feed more than one Freeview box or television set, with satelite reception you cannot. So, a Sky+ box with two receivers (so you can watch one thing and record another) has two cables connecting the box to the dish.
The cable that connects the dish to the receiver must be satellite grade cable. Whilst this looks superficially like the cable used to connect and aerial to a television, a higher grade cable is required for satellite reception.
Here is an image of a co-axial cable. This sort of cable is used to connect any type of receiving aerial to the reception equipment.
RG6, PF100 and PH100 are all types of coax cable that are suitable for the very weak signals that are received by a satellite dish. (The power is the same as you would receive from a one-bar electric heater on the moon).
The conductor in the centre passes the signals received from the dish to the set-top box. This is made from steel in RG6 cable, and from copper in the RF100 and PH100 types. This makes RG6 less suitable in the UK where rain can damage the cable.
The shielding is responsible for keeping unwanted external interference from damaging the signal. In the cheaper cable this will be a foil wrap, in better specified cables this is a braid (or mesh) of copper wires. The sheild in the RF100 covers 58% of the cable.
The non-conducting layer between the shield and the conductor is called the dielectric. This can be either a solid (RG6), foam (RF100) or air-spaced (PH100) dielectric. This makes the cables progressively more flexible (ie bendy without damage).
Your comments are always welcome. Please use the form below to add your thoughts or questions to this page. We will get back to you as soon as we can.
M. Urquhart Friday 27 November 2009 11:27PM
Since turning to Taggert on Wednesday, Thursday and this evening I cannot receive any other channels. All other channels give a 'No signal or scrambled' message. I have a humax foxsat-hdr box and a milton keynes postal code.(Is this even relevant?
I have just moved into an apartment building to find out the normal aerial cannot receive freeview. the building is equipped with a satellitedish. if i bought a freesatbox would i be able to run this off the existing dish?
Jamie - You should be able to connect a Freesat receiver to the existing dish. However you might not be able to connect a Freesat + or Sky + box. You could perhaps check out with a neighbour whether the existing Satellite installation to the flats manages this or not. Otherwise you could go for the Technisat HDFS Freesat receiver which will allow you to record from the receivers USB ports either to a USB pen drive or to an external USB Hard Drive. You would of course not have the range of recording features as this receiver is limited in having a single tuner. Thus stated it's a highly rated box with other plus features - Rated "What HiFi" XXXXX. Hope this helps.
Jamie - The Humax Freesat + can record with limited connectivity, but cost of around £250 as against the Technisat at around £159 + makes the Technisat a better buy. You can of course get an SD or a Non recording HD receiver that bit cheaper with a range of choice available on the High Street or online.
Gerald - If the dish is in good order then this would probably be OK but you wil require to replace the LNB to a universal type also making sure that the fitting is a standard 40mm and that the collar at the end of the boom arm matches that. Avoid getting a SKY type of LNB (Cheap from the likes of ebay) as the collar may be oval in shape and not match with the standard 40mm collar. Alternatively replace the sish and LNB - Probably best to get from a Sat dish supplier who will match the dish and LNB for you as a pack. - (LNB should be a Quad type (4outlets) to give you maximum connection flexibility. If your unsure about setting up or there is height involved best to get a professional to do the job for you and they will also supply you with all that's neccesary for "Freesat" reception.
hi, i've tried to connect a freesatbox but when i attach the satellitecable to the box the power to the box goes off. when i detach the cable the power to the box comes on again. i took the box back and got a replacement as i thought it was faulty but the same thing happens with the new box! anyone have any ideas what the problem might be?
Jamie - You shouldn't "Power - On" the receiver until you have made all other connections. Try as described if the receiver doesn't boot then switch off and unplug the mains plug. Leave for 5mins then re-plug switch on and you should then see the receiver reboot correctly.
Jamie, you now need to check cable connections at the receiver and LNB ends (if possible)- might be that you can't if the dish is roof or chimney mounted. Also may be that the issue is with the LNB itself as it's powered by the receiver via sat cable. Other than that you may need to call in an installer to check out- they will be able to check out the functionality of the LNB.
Jamie - One other thing you might try if you can is connect to a relative or a friends dish and this will at least determine that the receiver os OK or NOT. Rember though connect everything up first before you power up and switch on.
Hi, I’ve got an ex-Sky dish with a quad LNB and, having input my home location into an on-line dish pointing calculator, I’ve got the necessary elevation, azimuth and skew data for accessing the Astra satellites at 28.2E. I’m trying to connect the dish to a Humax Foxsat HDR (= Freesat +). I’ve double-checked all the connections but on booting-up, the Humax continually “failed to detect the satellite”. I know that the LNB is OK because I got a signal response (no idea which satellite) via my KONIG Satfinder Kit (otherwise not a very useful piece of kit in my experience). I shall try again later but in the meantime would be grateful for a bit of advice: (1) Should I be using true or magnetic azimuth (there is a 1.5 degree difference)? (2) can/should I be doing anything about “LNB Skew”? I can’t see how to adjust it and (3) can you suggest where I may be going wrong please? Thanks.
Keith: I would use Astra 2D at 28.2°E - LyngSat SatTracker to get the correct angles. The trick usually is to get the elevation set right and then have the dish's horizontals motion move to get the direction about right. Then move the dish in very small taps until you find the signal on the signal meter. You probably don't need to skew your LNB in the UK.
Many thanks for the advice, Brian. Should I use true - rather than magnetic - azimuth? The elevation angle to Astra 2 from here should be 25.6 degrees but I have just read that some dishes have a built-in offset angle - often about 20 degrees, but it varies - that has to be subtracted. Thus, in this case, I would only need to tilt the LNB bar to 5.6 degrees from the horizontal. As mentioned, I'm using a standard ex-Sky elliptical dish. Do you know whether this has a built-in offset angle and what it is please? Thanks.
Keith: Most dishes have calibration marks on them that shows the angle the dish is inclined when fitted to a true vertical surface. It's quite hard to visualise the angle from the dish as they are only a part of a parabola. If you can adjust the LNB by 5.6 degrees, then go ahead!
Tharindu: "The inclination of orbits of artificial satellites is measured relative to the equatorial plane of the body. The equatorial plane is the plane perpendicular to the axis of rotation of the central body. an inclination of 0 degrees means the orbiting body orbits the planet in its equatorial plane, in the same direction as the planet rotates", this is the case for geostationary satellites.
The "elevation" is the angle above the true horizon that a satellite appears from a given location. For geostationary satellites this will be a fixed value.
I am running a freesatbox from my sky dish but although my signal strength shows at 80%
I receive a 'no signal' message on most of my channels although they are picked up on install.
I was able to view all chnnels through my sky box(now refusing to switch on)
Is it a simple 'user error'?
ernie: The signal meter usually only shows the signal on a single transponder. Your dish is most likely slightly out of alignment and you are only getting the channels from one of the satellites in the cluster.
How can we watch UK tv in Austria we live about 100ks west of Salzberg and what size dish do we need - we already have a 1.10 mtr dish for BBC world CNN etc., we would like access to Sky for Sports films and although we speak and understand German it would be great to have a bit more English? Many thanks
Hi, We recently moved to Spain, Cadiz in Andalucia to be correct. I wanted to know what size dish I need to buy to be able to get Freesat here. I wanted to make a diy installation and connect the dish to a TBS DVB-S2 High Definition Digital Satellite Tuner PCI CardHD (DVB-S2/DVB-S) Receiver in my HTPC.
Your help would be very much appreciated as I do not know any local expats.
I have tried and tried to line up my satelite dish on a portable tripod to recieve freesat on my Sony Freesat TV. After numerous attempts i am thinking of giving up.
The TV reciever keeps stating that no signal and "faileed to find a satelitte". the dish is situated well clear of any obstructions, "in the middle of a very large field, can anyone suggest the least i could try and attempt as life without some TV is getting a little quiet, thanks
Hi have sky + HD working good but thinking of changing over to Freesat to avoid sky charges. If I purchase a Humax HD box to replace the existing sky+ box will it work with the existing dual LNBs or will it involve re- alignment of the dish.
thanks for your help....
best to use a Channel Islands postcode, as BBC1 CI and ITV1 Channels islands are regarded as being the strongest free to air BBC and ITV frequencies.
With a londonw postcode you rBBC1 London on 101 will go off in the afternoon, but with a BBC CI on 101 your BBC1 101 should be there almost 24/7 - dish size depending.
B: BBC CI and ITV CI are regarded as being the best regional variations channels for reception here in Spain - as they tend to be the best and "strongest" astra 2d vertical frequencies here in Spain.
If a Cambridge postcode was to be used, OK yu get BBC1 Cambridge on 101, but your 103 would be the slightly "weaker" ITV1 Anglia frequency.
And if you used a London postcode, then your 101 would be BBC1 london, an astra 2d horizontal frequency which is notoriously bad here in Spain even on the big 2.4m dishes, although your 103 would be ITV1 London, a "stronger" Astra 2d vertical frequency.
Its a bit of a juggling act, and why not many installers here actually recommend freesat boxes, but using a skybox and a freesatfromsky card, you can get the ITV on frequencies 12408 and 11973 even on a small 80cm dish here in Spain - where their FTA counter parts require a much bigger dish!