Hi, I have two digital freeview TV's running of two loft aerials, the aerials are not modern digital they are 20years old but look the same as the new one's, sometimes the picture is ok but more often i get lots of picture breakup, will a modern (digital) aerial solve this and could i run both tv's of one aerial, i am in a poor signal area?
Digital areal or not??
- Thread starter gemshan1
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No such thing as a digital aerial. What is often referred to as a digital aerial is a wide band aerial and in the pre-change over period because the digital transmission's were slotted in where ever there was a slot without cross channel interference there was a need for the wide band aerial.
However since the change over in the main the signals again have been grouped together so we in the main can all return to using lighter and smaller narrow band aerials which will cause less strain on the building structure.
The narrow band aerials were colour coded according to the band they covered normally a square plastic plug in the end. Where I live we have the same band as before change over so the old aerials work fine.
The power on the transmitters was reduced during change over but once completed will in most cases rise.
So the answer does depend on location. Aerials are interesting to say the least and I have a friend who uses 9 yargi beams together to bounce signals off the moon to communicate with USA (Morse Code 2M band) so one can stack aerials but it's not easy as the lenght of coax between them is critical so the normal is to ensure they have enough gain as made and there is nothing in the way. Putting aerials in the loft will not be best position so likely best idea is to remount outside.
Trees, aerial wires and other items can change what can be received my father lost signal when a neighbour put up an aerial also items like sky boxes which transmit in analogue can end up on same channel as digital signals which can degrade the signal.
The Digital signal is transmitted as about 6 blocks with something like 15 programs in each block. If you identify what programs are in each block and you find when the signal is bad it's all the programs from one block then this can go a long way to working out the problem. If they are on band edge likely new wider band aerial will help but in the centre of the band then likely a video game, VCR, Sky box or something is blocking the signal.
However since the change over in the main the signals again have been grouped together so we in the main can all return to using lighter and smaller narrow band aerials which will cause less strain on the building structure.
The narrow band aerials were colour coded according to the band they covered normally a square plastic plug in the end. Where I live we have the same band as before change over so the old aerials work fine.
The power on the transmitters was reduced during change over but once completed will in most cases rise.
So the answer does depend on location. Aerials are interesting to say the least and I have a friend who uses 9 yargi beams together to bounce signals off the moon to communicate with USA (Morse Code 2M band) so one can stack aerials but it's not easy as the lenght of coax between them is critical so the normal is to ensure they have enough gain as made and there is nothing in the way. Putting aerials in the loft will not be best position so likely best idea is to remount outside.
Trees, aerial wires and other items can change what can be received my father lost signal when a neighbour put up an aerial also items like sky boxes which transmit in analogue can end up on same channel as digital signals which can degrade the signal.
The Digital signal is transmitted as about 6 blocks with something like 15 programs in each block. If you identify what programs are in each block and you find when the signal is bad it's all the programs from one block then this can go a long way to working out the problem. If they are on band edge likely new wider band aerial will help but in the centre of the band then likely a video game, VCR, Sky box or something is blocking the signal.
Also, what sort of coax are you using?
Traditional low-loss coax, particularly if it's draped over the roof tiles where it can become damaged, is not too good for digital. What with an analogue signal would have been a slight picture degradation, a slight loss of sound quality, the odd white fleck, the odd shooshing sound etc, becomes with digital blocking and freezing.
Traditional low-loss coax, particularly if it's draped over the roof tiles where it can become damaged, is not too good for digital. What with an analogue signal would have been a slight picture degradation, a slight loss of sound quality, the odd white fleck, the odd shooshing sound etc, becomes with digital blocking and freezing.
@ gemshan1 if you want more specific advice, please divulge your postcode so we can check your predicted signal strength and channel allocations.
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ChrisFrost
As a rough rule of thumb being in the loft knocks about 1/3rd off an aerial's sensitivity. That's liveable if in a strong to medium signal area and running just one TV from the output. If you start in a poor signal area though you really need all the signal level you can get.
Outdoor mounting is the best option. If it definitely absolutely positively must be in the loft because of building controls and not just for convenience sake then a higher gain aerial is the obvious choice.
There are a huge numbers of aerials to choose from that it can be off-putting. Everyone seems to have their own recommendation. I'm no different. I supply a lot of gear to caravaners and canal boat owners. They have the same sorts of problems with reception. Sites and moorings are rarely in good reception areas. I do well with a £25 aerial that really seems to suck in the signals where others don't. The directors (the bars that look like saw fish teeth) are solid aluminium about as thick as a Biro rather than the more typical bent alu sheet.
If you want to run two TVs then either a passive splitter or a low gain aerial amplifier would be my recommendation. Getting really good signal from the aerial then losing a little through a splitter is far better than running a poor aerial and over-boosting the weak signal from it. A well made (metal) indoor 2-way splitter is about £4. An outdoor weatherproof one is about £8.
Finally, the cable. If pennies are really tight and all the runs are indoors then a basic shielded coax will suffice at approx 30p/m. For outdoor runs I don't use anything other than a benchmarked WF100. It's a bit stiffer but far better made an will last years longer than the cheap stuff. It's 70p/m. That's the kind of gear you want.
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