Omega Owners Forum
Chat Area => General Discussion Area => Topic started by: Tonka. on 29 August 2010, 16:54:16
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We have Freeview TV picked up through a class 2 digital aerial.
(http://www.ukfree.tv/styles/images/aerials/aerials2.png)
This signal is split to feed three TV's.
We do not have a huge selection of channels and some of those channels are blocky and hesitant.
How could I possibly improve:
[size=12]A: the amount of channels received
B: The quality of the existing channel reception[/size]
Do boosters actually work or just boost the background interference?
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We have Freeview TV picked up through a class 2 digital aerial.
(http://www.ukfree.tv/styles/images/aerials/aerials2.png)
This signal is split to feed three TV's.
We do not have a huge selection of channels and some of those channels are blocky and hesitant.
How could I possibly improve:
[size=12]A: the amount of channels received
B: The quality of the existing channel reception[/size]
Do boosters actually work or just boost the background interference?
i had a booster at my other flat as i couldnt get channel 5, made no difference to my tv, freeview is going downhill in my opinion, get bored with the same thing over and over again
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Make sure your cable is good.
Possibly get a DAT 75 aerial as per picture
Boosters make little difference
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How are you splitting the signal Tonk?
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Make sure your cable is good.
Possibly get a DAT 75 aerial as per picture
Boosters make little difference
There was a conversation a year ago where Mark DTM suggeted the DAT 45 was the best aeriel that would be required.
http://www.easyflip.co.uk/CPC_2010/book.html Page 17, not sure what Margin Rising Device does or whether it is required or not, but the specs of the 45 and 75 are there.
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How are you splitting the signal Tonk?
Using a similar thing to this
(http://www.o-digital.com/uploads/2179/2191-2/2400GHz_2_Way_3_Way_4_Way_Splitter_8231_8331_8431_144.jpg)
Straight from the outside aerial, then sent three ways :y
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If you take out all the splitters and feed a single TV from the antenna what is the signal like?
What Strength / Quality does the TV report?
A decent amplifier might help simply to compensate for the losses in the couplers, but it's much better to get a decent signal in the first place from the antenna, so a decent antenna, correctly aligned and decent feeder coax.
If changing the antenna, you might well be better off looking up the transmitter that feeds you and getting an antenna of the proper group rather than a wideband antenna such as the DAT75 mentioned. Depends how wide the carriers from the transmitter are spread but a narrow band antenna will give better gain, narrower beamwidth and better front-to-back ratio than a wideband for a givenamount of metal in the sky.
Find out what the signal's like out of the antenna first though.
Kevin
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How are you splitting the signal Tonk?
Using a similar thing to this
http://www.o-digital.com/uploads/2179/2191-2/2400GHz_2_Way_3_Way_4_Way_Splitter_8231_8331_8431_144.jpg
Straight from the outside aerial, then sent three ways :y
Your problem may be there Tonk. I had the same problem solved by distributing the signal by means of a powered amp that supplies an additional 6-8 Db gain on each outlet. (similar to);
http://www.aerialshack.com/slx4b-signal-distribution-amplifier-with-digital-bypass-p-799.html?osCsid=ohgcr837uvlnvj7s9fqrkmqs83
On the other hand you can also have trouble such as you describe if the signal you're getting is too strong. I proved this when I decided to try a wideband aerial similar to yours. I have a clear line of sight to the transmitter and found that the new aerial provided too much gain restricting the number of channels I could receive and introducing artifacts onto many others.
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Labgear distribution amps are good, giving a gain per channel of about 6dB, something like this ...
http://cgi.ebay.co.uk/Labgear-TV-FM-Satellite-6-Way-Distributor-Amplifier-/270626689743?pt=UK_ConElec_TVAerials_RL
I agree with Kevin about the aerial, if the input signal is crap to begin with and you amplify it all you get is even bigger crap.
Ken
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Key thing here is that there is no such thing as a digital aerial, your (simply lol) in need of a wideband type.
The most ideal for such a task is actualy a Log Periodic and in the last year or so there have been some really good ones appear on the market which push the DAT45 very close.
There is still nothing that gets close to a DAT 75 though.
As for splitting, your using a passive or inductive splitter and hence signal loss will occur, you need an amplified item as you will be getting probably a quarter of the aerial output tops to each tv point!
I have to say that I also really rate a loft box for distribution in domestic apps.
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Amplifiers will only amplify the signal they receive. If the signal is poor, you will experience no gain. (Play on words there).
Anyway.
As mentioned above, you could try an attenuator on the input... this will help if the signal is 'too strong'. Unlikely with a Digital Broadcast Signal, but not unheard of.
If it's not too much of a ball-ache, I'd start by upgrading to the best Coaxial cable you can find, thats if you aren't already using Satellite grade stuff. (you dont get much better than that (even if specific manufacturers say so)).
The splitters you are using are the correct type (for non amplified), not the piss poor triangular things which have losses greater than that of Northern Rock.
Check and double check your coaxial fittings. I'd be inclined to remove them all, even if they dont look suspect and fit new ones, ideally with a proper crimping tool.
All of this would be easily cleared up if you knew someone with a signal tester. :y
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Loose the splitter.....its the key thing thats loosing your signal
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Things are looking up :)
I have taken the splitter out and scanned for channels directly from the aerial. Loads of channels now, even some gay pink ones I have never heard of ;D ;D
Point proven. Splitters leak signals like a sieve ::)
I will be boosting the signal now I have proved I have one. Thanks guys :y :y :y
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Things are looking up :)
I have taken the splitter out and scanned for channels directly from the aerial. Loads of channels now, even some gay pink ones I have never heard of ;D ;D
Point proven. Splitters leak signals like a sieve ::)
I will be boosting the signal now I have proved I have one. Thanks guys :y :y :y
The dont leak them.....they distribite the received power.
They are alos generaly slightly lossy.
Do consider a loftbox though, very good
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Where are you Tonk?
I'm right next to the east end of the Cathedral, with an (oversized) aerial inside my roof - which is below the level of the surrounding rooftops and I get a cracking picture.
The only real way is to have a good aerial signal (mine comes from Belmont), and then amplify it before it's spilt to the other sets. You can get a good amp/splitter for about £30 or so, but best to get it working properly with one set first before you start splitting it.
Coax cable does degrade with time, but there is some good stuff around now for a reasonable price.
Once the analogue signal gets switched off the freeview channels will be shuffled around again and the signal power increased - so things will get better. Can't help with the content though :-/
HTH - Rob
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Where are you Tonk?
I am up on Glebe Park Rob and am also pointing at Belmont.
I will take all your suggestions on board and get a better signal when time allows.
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The dont leak them.....they distribite the received power.
Thats what I meant ;D
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From your pictures it looks like I have a class 3 aerial running 2 TV through a mains booster, was working ok with a bit of interference but yesterday went through the whole system remaking all conections and fine adjusting the aerial and its made a good improvement now get 65% to 90% signall strength across all channels.