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[platty]

I am trying to sort the aerial out in my house. When I moved in there was an old UHF aerial, big long thing in the loft which was replaced by a new aerial especially for digital signal.

I first ran a cable out of the loft and straight into my Digibox. Tuned it all in and got great reception on all channels once I had pointed the aerial in the right direction.

But, when I swapped the cable back to the original one and plugged the Digibox into the wall socket - the reception wasn't very good on perhaps half of the channels    I then established that the signal strength must be deteriorating somewhere along the route.

I have got 2 further sockets, in the bedroom and in the kitchen. There must be a splitter somewhere - but where do you think I could find this?

Sorry about the long post  

[Lizzie_Zoom]

I am trying to sort the aerial out in my house. When I moved in there was an old UHF aerial, big long thing in the loft which was replaced by a new aerial especially for digital signal.

I first ran a cable out of the loft and straight into my Digibox. Tuned it all in and got great reception on all channels once I had pointed the aerial in the right direction.

But, when I swapped the cable back to the original one and plugged the Digibox into the wall socket - the reception wasn't very good on perhaps half of the channels    I then established that the signal strength must be deteriorating somewhere along the route.

I have got 2 further sockets, in the bedroom and in the kitchen. There must be a splitter somewhere - but where do you think I could find this?

Sorry about the long post  

To start with all the cable should be of digital quality, not the old analoge stuff.

Then you need a power driven multi-set booster box in your loft to distribute, via separate (ditigal) cable, the aerial signals to each room/tv.

All splitters should be disregarded as they dissapate the strength of the signal.

[amigov6]

As Lizzie said really, my integrated freeview telly struggled a bit on the old loft ariel, recently bought a little freeview plasma/lcd telly for the bedroom, no chance running two. Local company came round, fitted two loft ariels, booster & new co ax, 20 mins. £100 (in cash) 8-)
     Got ALL channels & music up & downstairs & ready for the digital change over.

[Marks DTM Calib]

In this case Lizzie, I agree not.

A PF100 or equivalent cable will be better and mainly down to the screening (double screened braid plus foil) but, its by no means essential for digital use. The only real major benefit is that the better screen should reduce losses slightly and stop the pickup of stray signal via the coax which in tern reduces multipath (the one thing digital cant realy tolerate).

As for the splitters, I am all for them....of the right type and in the right setup. Some splitters are resistive and hence lossy (over and above the fact that the signal will be 50% down on each branch), the better ones utilise a balun transformer which reduces the loss.

The thing with any succesful reception setup is to get the right aerial and to be quite frank, the wideband ones (there is no such thing as a digital aerial, this is a marketing con) they sell in the likes of the sheds are both a rip off and only average quality.

The ideal setup would be a good quality high gain aerial of Yagi or Log-periodic setup and a balun based splitter.....get the gain in the aerial rather than adding harmonics in an electronic amp (there noisey buggers).

If your aerial cant support this then you are faced with needing an amp (although only to overcome splitter losses as you cnt realy boost a poor signal!).....the theory is to sight it as close to the antenna as possible so you can boost the signal before any cable loss....but, be warned, cheap amps are noisey buggers and can inject multipath interference back into the antenna!

My current wideband aerial of choice......a Televes DAT45.

As for this issue.....you need to find where and how the other wires are spliced in.....to many times I have found the cores and screens just twisted together giving major inpedance miss matching (which on ayagi, caues it to squint!)....even by the pros  

[amigov6]

In this case Lizzie, I agree not.

A PF100 or equivalent cable will be better and mainly down to the screening (double screened braid plus foil) but, its by no means essential for digital use. The only real major benefit is that the better screen should reduce losses slightly and stop the pickup of stray signal via the coax which in tern reduces multipath (the one thing digital cant realy tolerate).

As for the splitters, I am all for them....of the right type and in the right setup. Some splitters are resistive and hence lossy (over and above the fact that the signal will be 50% down on each branch), the better ones utilise a balun transformer which reduces the loss.

The thing with any succesful reception setup is to get the right aerial and to be quite frank, the wideband ones (there is no such thing as a digital aerial, this is a marketing con) they sell in the likes of the sheds are both a rip off and only average quality.

The ideal setup would be a good quality high gain aerial of Yagi or Log-periodic setup and a balun based splitter.....get the gain in the aerial rather than adding harmonics in an electronic amp (there noisey buggers).

If your aerial cant support this then you are faced with needing an amp (although only to overcome splitter losses as you cnt realy boost a poor signal!).....the theory is to sight it as close to the antenna as possible so you can boost the signal before any cable loss....but, be warned, cheap amps are noisey buggers and can inject multipath interference back into the antenna!

My current wideband aerial of choice......a Televes DAT45.

As for this issue.....you need to find where and how the other wires are spliced in.....to many times I have found the cores and screens just twisted together giving major inpedance miss matching (which on ayagi, caues it to squint!)....even by the pros  

I was going to say that but discretion got the better of me!!!! [smiley=2vrolijk_08.gif]

[Marks DTM Calib]

Lol.... having studied comms for many moons......and having done some antenna thoery etc at Uni....plus having been involved in bloody pulse masks, return loss and noise immunity testing....you get to know more than your average aerial fitter on this subject!

[Mr Skrunts]

Lol.... having studied comms for many moons......and having done some antenna thoery etc at Uni....plus having been involved in bloody pulse masks, return loss and noise immunity testing....you get to know more than your average aerial fitter on this subject!

Thats going to be my problem in the new year, I shall be wanting a new aerial, just checked the price of the one you mentioned on fleabay, then went to check the price on CPC. Quite a difference when you add the carriage.

The problem with Aerial fitters are they they go for the cheapest.  I like the Aerial mentioned just on looks alone so I would easily if someone showed me something flashy that looked the part.

Armed with what Mark has posted I at least feel at ease asking what Aerial and cable the guy will be using and see what replies I get.

I also want/need to split the signal 4 maybe even 5 ways (maybe double outlet for a TV tuner card in my PC)

[cem_devecioglu]

Lol.... having studied comms for many moons......and having done some antenna thoery etc at Uni....plus having been involved in bloody pulse masks, return loss and noise immunity testing....you get to know more than your average aerial fitter on this subject!

Thats going to be my problem in the new year, I shall be wanting a new aerial, just checked the price of the one you mentioned on fleabay, then went to check the price on CPC. Quite a difference when you add the carriage.

The problem with Aerial fitters are they they go for the cheapest.  I like the Aerial mentioned just on looks alone so I would easily if someone showed me something flashy that looked the part.

Armed with what Mark has posted I at least feel at ease asking what Aerial and cable the guy will be using and see what replies I get.

I also want/need to split the signal 4 maybe even 5 ways (maybe double outlet for a TV tuner card in my PC)

very practical..no need for remote

[Marks DTM Calib]

Lol.... having studied comms for many moons......and having done some antenna thoery etc at Uni....plus having been involved in bloody pulse masks, return loss and noise immunity testing....you get to know more than your average aerial fitter on this subject!

Thats going to be my problem in the new year, I shall be wanting a new aerial, just checked the price of the one you mentioned on fleabay, then went to check the price on CPC. Quite a difference when you add the carriage.

The problem with Aerial fitters are they they go for the cheapest.  I like the Aerial mentioned just on looks alone so I would easily if someone showed me something flashy that looked the part.

Armed with what Mark has posted I at least feel at ease asking what Aerial and cable the guy will be using and see what replies I get.

I also want/need to split the signal 4 maybe even 5 ways (maybe double outlet for a TV tuner card in my PC)

I would go for a DAT45 with MRD (head amp) and then a loft splitter.....buy on ebay and pay for fitting.

[Marks DTM Calib]

I should add that with a quality aerial.....a diyer can get a very good signal just aligning using a compass (having taken the bearing from a map) in areas with reasonable simple signal conditions. Plus most aerials have a good 10-15 degree acceptance angle!

One of the reasons why some installers have to use an alignment meter is becasue tehy use cheap nasty Yagis (at anything from 3 quid upwards) which actualy have a 300ohm balanced dipole....connect this to 75 ohm coax and the array squints and no longer has the main reception lobe down the axis of the beam!

[Mr Skrunts]

Whats the difference between the DAT 45 and DAT75?

[Marks DTM Calib]

Whats the difference between the DAT 45 and DAT75?

About 800mm......ask Matchless....he bought the wrong one.....its rather huge!

Real answer is of course its higher gain.....narrower acceptance angle....but beware, its big (nearly 2m's long), heavy and as a result needs a stronger pole to take the wind loading

[Marks DTM Calib]

And beware, some of the Televes aerials are orange....so make sure you ask for a black one!

[Mr Skrunts]

Whats the difference between the DAT 45 and DAT75?

Just found some info

http://cpc.farnell.com/jsp/level5/module.jsp?moduleId=cpc/274460.xml

[dippydave]

i have a televes 45 that does indeed look nice. the only reason i got it was that it was on a steal of an offer from http://www.tlc-direct.co.uk/Main_Index/Aerials_Index/index.html 3 years ago. in my mis-informed naivety back then i fell for the 'digital' aerial blurb as well. Worst thing is I haven't even connected it to anything as i still only use cable tv!! It just looks pretty on my chimney   I had plans for freeview boxes and to ditch telewest/virgin but haven't got round to it!

Having read around the web and especially info from this website  hat has a heck of a lot of fun, useful and techy knowledge:
http://www.aerialsandtv.com/index.html
 I realised how RF signals can be really picky and it's a precise non exact science! ('Black Art' they call it!) It is true that digital signals are less forgiving than the old analogue but it really depends where in the county you are!

I'm pretty sure  that I made a booboo with the televes though. Living four miles away from one of the most powerful transmitters in the country i should've gone for a Band B DM-log periodic type aerial that would get all the channels and not put too much gain on it. So maybe when i get my ladders out again and borrow a roof climber one i may swap the blooming thing! first thing will be to test the signal tho, i may well get away with attenuating it down!

as for home RF networks i've fitted a few with pf100 and rg6/58/59 cable and all have been fine. They had individual cables to each room from the loft and a double run to the main av place. so the tv/freeview can get the aerial signal, then send it all back up to the splitter and then everyroom can tune in to freeview, dvd, anything! my bro loves it.

in his loft we fitted this: http://www.screwfix.com/prods/69457/Electrical/TV-Range/Amplifiers-Distribution/Labgear-Home-Distribution-Unit-8-Way
but it was cheaper then! and there's a fab wholesaler in  birmingham that does all av stuff at a fraction of retail sheds and online alike. Only thing is knowing what to buy!

to answer the OP, i would've thought the splitter would be in the loft, but it may well be under a floorboard somewhere. or even the cables could be looped in and out of each aerial socket having been twisted together? (YIKES!  )

If you can't find the installed stuff, i'd be inclined to start afresh and then you know it's all up to scratch.

sorry bout my long reply post, but i spent a long time researching onetime!