Question:
As I'd guessed my weak signal only gives me 5 (perfect - ITV1, ITV2, Ch4 and 2 x Text) channels with my new Grundig 1500 box. Local aerial installers are quoting me £200 for upgrade. A friend reckons I should remove 2 of the 3 outlets from my current aerial to boost the signal and if that doesn't work simply buy a mast/decent aerial and fix it up there myself. Any thoughts ?
You can buy all the equipment yourself (most from big B&Qs etc.) and do a decent job very easily as long as you have access to your roof. It really isn't rocket science.
I got quoted +£300 for two sockets "digital ready with RGB":rolleyes: ). I did the whole thing myself for <£100.
Use satellite coax as it's double screened and digital terrestrial doesn't like electromagnetic spikes (about £20 for 50 meter drum at B&Q). Keep the cable as short as possible and only put splitters and joints in if you have to. Use a low gain masthead amplifier (£10) and power supply (they look like signal boosters), be aware that over amplification can swap digital decoders.
http://www.maxview.ltd.uk/ supply most of the stuff, find out about what you can get here
http://www.maxview.ltd.uk/downloads.html has guides that will help you work out what you need.
Take care when you're up a ladder and on the roof, don't walk backwards!
Thank you very, very much, andymc. You have confirmed what I suspected all along ! Much appreciated. :)
andymc, I wonder if I might bend your ear once more ? I've got hold of some rather cool co-ax and I've ID'd an aerial. I have also, via use of a signal booster, gained a few channels, so I feel confident that a new aerial will give me what I want. (Currently I have two tiny aerials on crap co-ax both split into two outlets.)
My question is re: masthead amps and power supplies - are these critical ? (I suspect your answer will be yes !) I ask because my low roof will allow me access to the chimney but as for attaching an amp and then getting a power cable into the - well insulated - loft... well that doesn't appear to be so easy. Help appreciated - many thanks again.
Originally posted by GK
As I'd guessed my weak signal only gives me 5 (perfect - ITV1, ITV2, Ch4 and 2 x Text)
i don't understand:confused: how can you get some perfect channels and not get others? don't they all come from the same transmitter, and as such all channels should be the same signal strength? or is terretial digital even more needlessly complicated?:rolleyes:
bloody digital tv:mad: its supposed to be as easy as "just plug it in your TV". bloody liars:mad:
You know how we used to waggle portable tv aerials around - you might get a strong bbc1 but a manky itv in 1 position, vice versa in the other ...? Kinda the same with digital tv only to a much lesser extend (we're not trying to use silly loop top aerials!!). Yes, all the multiplexes will be coming from 1 transmitter, theres 6 of them, between them they carry all the DVB channels. Each one of the DVB multiplexes basically equals the space for 1 normal terrestrial channel. When I 1st got my ITVD box I could only get 5 muxes, and some of them were weakish. 1st thing was to disconnect the splitter in my loft - this previously split my aerial into 2 cables, 1 to the bedroom, 1 to the lounge. I removed the splitter and just connected the lounge to the aerial, big signal strength improvement immediately but I was still missing a mux. My method for determining the aerial required is a bit ... err .. unrecommended ... I went and picked up a couple from argos (they do a normal and a high gain system), using these "handheld" i found that my roof aerial wanted to be a couple of degrees to the left of its present position for perfect DVB reception ... the high gain got bolted up inside the roof (can get outside without mulitple ladders) and I've not looked back.
Couple of things to bear in mind. TV aerials can be banded - they'll only pick up signals in their tuned frequency band. A wideband aerial will pick up all TV frequencies but at a lower level. Personally I needed a wideband as my terrestrial stuff (from sandy heath transmitter) is down in the 21 and 30s, my digital goes right up to the 50 and 60s. For info on the frequencies in your area try the DTG website (http://www.dtg.org.uk/retailer/index.html) , use the postcode search option to find which transmitter you're using, then use the transmitter rollout pages to see which frequencies you're transmitting.
Hope thats of some use to someone ....
Duncan
Of great use, thank you very much. I definitely feel that the installers who all quoted me £200 last week were exaggerating the nature of my problem/area. Now that I have a number of Freeview channels from a tiny (2 outlet) aerial/crap co-ax combination, I'm confident a decent digital-capable aerial with the awesome-looking cable (proper copper foil screening) I've bought will fill the gaps. For an outlay of about £50 and a morning's work.
GK -
Is a masthead amplifier critical? Well I got an OK signal on all MUXes without one and using a splitter in the middle but it was very prone to electromagnetic interference and as I live in the city this made it pretty annoying. Instead of a bit of snow you get on analogue, you get pixelation of the picture accompanied by a speaker shattering crack.
I had some misconceptions about masthead amplifiers when I got into this that perhaps I can iron out for you.
The mast head amplifier is about the size of a packet of fags. You attach a short length of co-ax to the aerial and a long length back to your TV socket. The amplifier itself is a weatherproof cover over a simple circuit board and you can attach it to the pole that supports your aerial (the masthead) with a cable tie.
Next to the TV socket you plug in a power supply that looks a lot like a signal booster.
One side goes to the socket (and on up to the amplifier) and the other goes to your DTV receiver.
The side going to the roof is powered in the same way as satellite co-ax is used to power the receiver on the dish. This allows the box on the roof to convert the very low power signal from the aerial into a much higher level signal for the journey down to the amplifier. This makes it less prone to noise which a ground level signal booster would make worse.
There is still only one wire between all the components and you shouldn't need to worry about running any extra cables other than replacing the old co-ax you have already decided to swap.
I have seen masthead amplifiers (on the web) that have one downlead to power the amplifier and supply signal in one location and an additional boosted downlead to go to a second socket.
This means you don't have to split the signal elsewhere so you don't have to worry about having a mixture of powered and unpowered (which wouldn't work and would probably break stuff) or running unnecessary links between the sockets downstairs.
I was going to do this to my set up when ITVD went belly up and all the channels disappeared. I've now got cable so I've not been back to it.
IIRC there is more information about masthead amps in the links above.
You almost definitely need a wideband aerial to get a good analogue and digital signal but the link above should tell you what's recommended. You can usually only get type specific ariels from specialist suppliers.
I would recommend using one as interference and its accompanying noise is very, very, very irritating and totally ruins the experience where I live. Depending on where you live it may be less or no problem. You can always try without and if necessary add the amplifier and power supply later which will cost a total of around £30.
Cheers!
andymc, what can I say ? Thanks again. For some insane reason I had decided that the power supply needed to go into the loft ! Oh dear ...
The reality you describe obviously adds no pain to the job and seems to be worth it. Thanks again - I'll let you know how I get on at the weekend, but let me ask you one final question. Can a masthead amplifier and power supply be mutually exclusive ? Does fitting the amplifier demand the inclusion of the supply, or can I add the supply later. Maplins are out of stock on the supply and if I'm going up on the roof I would obviously prefer to get the job completed in one climb ! (I suspect the answer has to be yes but best to ask based on my previous presumptions ...)
I think you'll need to use both, I would expect the amplifier to at the least degrade the signal if it's not being powered, it may even block the signal completely.
You could test wire the amplifier at ground level into your existing wire and see if you still get a TV picture through it without the power supply. At least that way you'll know without climbing the ladder!
Best bet would be to wait until you can get all the bits together at once as it's hardly the season to be climbing up on your roof any more than you have to.
Do as much wiring and assembly at ground level before you go up the ladder as its safer that way - you stand less chance of losing little fiddly bits and you stand less chance of falling off too!
Answers:
You can buy all the equipment yourself (most from big B&Qs etc.) and do a decent job very easily as long as you have access to your roof. It really isn't rocket science.
I got quoted +£300 for two sockets "digital ready with RGB":rolleyes: ). I did the whole thing myself for <£100.
Use satellite coax as it's double screened and digital terrestrial doesn't like electromagnetic spikes (about £20 for 50 meter drum at B&Q). Keep the cable as short as possible and only put splitters and joints in if you have to. Use a low gain masthead amplifier (£10) and power supply (they look like signal boosters), be aware that over amplification can swap digital decoders.
http://www.maxview.ltd.uk/ supply most of the stuff, find out about what you can get here
http://www.maxview.ltd.uk/downloads.html has guides that will help you work out what you need.
Take care when you're up a ladder and on the roof, don't walk backwards!
Answers:
Thank you very, very much, andymc. You have confirmed what I suspected all along ! Much appreciated. :)
Answers:
andymc, I wonder if I might bend your ear once more ? I've got hold of some rather cool co-ax and I've ID'd an aerial. I have also, via use of a signal booster, gained a few channels, so I feel confident that a new aerial will give me what I want. (Currently I have two tiny aerials on crap co-ax both split into two outlets.)
My question is re: masthead amps and power supplies - are these critical ? (I suspect your answer will be yes !) I ask because my low roof will allow me access to the chimney but as for attaching an amp and then getting a power cable into the - well insulated - loft... well that doesn't appear to be so easy. Help appreciated - many thanks again.
Answers:
Originally posted by GK
As I'd guessed my weak signal only gives me 5 (perfect - ITV1, ITV2, Ch4 and 2 x Text)
i don't understand:confused: how can you get some perfect channels and not get others? don't they all come from the same transmitter, and as such all channels should be the same signal strength? or is terretial digital even more needlessly complicated?:rolleyes:
bloody digital tv:mad: its supposed to be as easy as "just plug it in your TV". bloody liars:mad:
Answers:
You know how we used to waggle portable tv aerials around - you might get a strong bbc1 but a manky itv in 1 position, vice versa in the other ...? Kinda the same with digital tv only to a much lesser extend (we're not trying to use silly loop top aerials!!). Yes, all the multiplexes will be coming from 1 transmitter, theres 6 of them, between them they carry all the DVB channels. Each one of the DVB multiplexes basically equals the space for 1 normal terrestrial channel. When I 1st got my ITVD box I could only get 5 muxes, and some of them were weakish. 1st thing was to disconnect the splitter in my loft - this previously split my aerial into 2 cables, 1 to the bedroom, 1 to the lounge. I removed the splitter and just connected the lounge to the aerial, big signal strength improvement immediately but I was still missing a mux. My method for determining the aerial required is a bit ... err .. unrecommended ... I went and picked up a couple from argos (they do a normal and a high gain system), using these "handheld" i found that my roof aerial wanted to be a couple of degrees to the left of its present position for perfect DVB reception ... the high gain got bolted up inside the roof (can get outside without mulitple ladders) and I've not looked back.
Couple of things to bear in mind. TV aerials can be banded - they'll only pick up signals in their tuned frequency band. A wideband aerial will pick up all TV frequencies but at a lower level. Personally I needed a wideband as my terrestrial stuff (from sandy heath transmitter) is down in the 21 and 30s, my digital goes right up to the 50 and 60s. For info on the frequencies in your area try the DTG website (http://www.dtg.org.uk/retailer/index.html) , use the postcode search option to find which transmitter you're using, then use the transmitter rollout pages to see which frequencies you're transmitting.
Hope thats of some use to someone ....
Duncan
Answers:
Of great use, thank you very much. I definitely feel that the installers who all quoted me £200 last week were exaggerating the nature of my problem/area. Now that I have a number of Freeview channels from a tiny (2 outlet) aerial/crap co-ax combination, I'm confident a decent digital-capable aerial with the awesome-looking cable (proper copper foil screening) I've bought will fill the gaps. For an outlay of about £50 and a morning's work.
Answers:
GK -
Is a masthead amplifier critical? Well I got an OK signal on all MUXes without one and using a splitter in the middle but it was very prone to electromagnetic interference and as I live in the city this made it pretty annoying. Instead of a bit of snow you get on analogue, you get pixelation of the picture accompanied by a speaker shattering crack.
I had some misconceptions about masthead amplifiers when I got into this that perhaps I can iron out for you.
The mast head amplifier is about the size of a packet of fags. You attach a short length of co-ax to the aerial and a long length back to your TV socket. The amplifier itself is a weatherproof cover over a simple circuit board and you can attach it to the pole that supports your aerial (the masthead) with a cable tie.
Next to the TV socket you plug in a power supply that looks a lot like a signal booster.
One side goes to the socket (and on up to the amplifier) and the other goes to your DTV receiver.
The side going to the roof is powered in the same way as satellite co-ax is used to power the receiver on the dish. This allows the box on the roof to convert the very low power signal from the aerial into a much higher level signal for the journey down to the amplifier. This makes it less prone to noise which a ground level signal booster would make worse.
There is still only one wire between all the components and you shouldn't need to worry about running any extra cables other than replacing the old co-ax you have already decided to swap.
I have seen masthead amplifiers (on the web) that have one downlead to power the amplifier and supply signal in one location and an additional boosted downlead to go to a second socket.
This means you don't have to split the signal elsewhere so you don't have to worry about having a mixture of powered and unpowered (which wouldn't work and would probably break stuff) or running unnecessary links between the sockets downstairs.
I was going to do this to my set up when ITVD went belly up and all the channels disappeared. I've now got cable so I've not been back to it.
IIRC there is more information about masthead amps in the links above.
You almost definitely need a wideband aerial to get a good analogue and digital signal but the link above should tell you what's recommended. You can usually only get type specific ariels from specialist suppliers.
I would recommend using one as interference and its accompanying noise is very, very, very irritating and totally ruins the experience where I live. Depending on where you live it may be less or no problem. You can always try without and if necessary add the amplifier and power supply later which will cost a total of around £30.
Cheers!
Answers:
andymc, what can I say ? Thanks again. For some insane reason I had decided that the power supply needed to go into the loft ! Oh dear ...
The reality you describe obviously adds no pain to the job and seems to be worth it. Thanks again - I'll let you know how I get on at the weekend, but let me ask you one final question. Can a masthead amplifier and power supply be mutually exclusive ? Does fitting the amplifier demand the inclusion of the supply, or can I add the supply later. Maplins are out of stock on the supply and if I'm going up on the roof I would obviously prefer to get the job completed in one climb ! (I suspect the answer has to be yes but best to ask based on my previous presumptions ...)
Answers:
I think you'll need to use both, I would expect the amplifier to at the least degrade the signal if it's not being powered, it may even block the signal completely.
You could test wire the amplifier at ground level into your existing wire and see if you still get a TV picture through it without the power supply. At least that way you'll know without climbing the ladder!
Best bet would be to wait until you can get all the bits together at once as it's hardly the season to be climbing up on your roof any more than you have to.
Do as much wiring and assembly at ground level before you go up the ladder as its safer that way - you stand less chance of losing little fiddly bits and you stand less chance of falling off too!
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