Poor Freeview reception..

[Jay6]

Hi to all. ..ok, i'm new here, so noob-gloves on please lol. ..I have a freeview box, a loft aerial, and a signal booster. For about 50% of the time I can view all channels with no problems. However, the rest of the time the picture and sound are broken. That is to say, very much like when a dvd skips. Pixels on the screen, and the audio sounds like a broken mobile phone call. When this happens the BBC channels are barely watchable, with ITV channels disappearing alltogether. This can last for minutes, hours, sometimes days. ...what can I do to resolve this? Getting on the roof isn't an option, so is there a device that can further increase my signal? What could be causing it in the first place? ..any advice greatly appreciated.

[Jay6]

Bbc channels are always more reliable than the itv channels. But I have never been able to watch dave, sky3, virgin1, or listen to most of the radio. I really feel like i need to increase the signal. But how?

[Welshchris]

do u have an outdoor ariel?

[Smilie]

tried any of those indoor aerials??
haven't tried them myself but it might be worth a try

try and buy it from a place where u could return it if its no good

[beeman]

1 important question, where is the signal boster?

is it in the loft just after the ariel or just before going into your freeview box?

if its the latter move it into the loft. the problem with singal bosters is they bost the entire signal comming into it, so if theres interfearence caused by a long line of coax then the interfearence gets bosted along with the wanted signal. putting the boster at the head (right after the areal) will provent that.

You are receiving a weak signal. There are two things you can try:

1. Put a bigger aerial in the loft. What size is the current one?
2. Use a 'mast head' amplifier. A signal booster placed behind the TV will amplify the signal but it will also amplify any interference that has been absorbed by the cable between the aerial and the Freesat box. A mast head amplifier is a signal booster located right next to the aerial. It boosts the pure signal received by the aerial and passes that down the cable to your Freesat box and is much more effective.

[nodrogd]

The BBC Mux has a more robust signal than the ITV so will tend to perform better pre-switchover. If you are using an indoor aerial or the signal is weak, you are more prone to impulse interference from household electrical equipment. Also if you are near a busy road, passing traffic can also cause problems.

Is the aerial the correct group to pick up all the digital channels in your area. My present aerial does not, and loses two MUX in anything from bad weather to birds sitting on it !

[Jay6]

Wow! Thanks for all the responses guys. ...ok, i'll try and answer everyone. The booster I have is next to the freeview box, it plugs into the mains. The aerial in the loft doesn't have an amplifier, and although its an outdoor aerial, its pretty small. (argos page 406, item 2). Judging by the many other types of aerials that are available, I'm thinking that I need a better one. But I have no idea where to start. From the little knowledge i've gathered i'm thinking that I need a High Gain, wide-band aerial with built in amplifier. Would that be the best way to go?

[nodrogd]

If your aerial is in the loft, then try to steer clear of wideband aerials if you can. Because these aerials pick up all available channels they have relativley poor gain compared to a grouped aerial. You are effectivley paying for more hardware than you really need in a confined space. Which transmitter do you receive from ?

[Jay6]

Its dover, according to that search thingy linked on this site. ..grouped aerial? Yes, i've read something about those. That what the 21-68 thingy is all about right? Well, which group aerial should I get? For me, bbc channels are on 45, and 58. Itv channels are on 42, dave and sky3 are on 57, virgin1 and most radio is on 60. If i get a group-specific aerial does that mean I won't get some of those channels? ...urgh, now i'm really confused. Lol.

[nodrogd]

The correct group aerial for Dover is Group C/D. According to the Digital TV Group website the reception channels are Mux 1 (BBC) 68, Mux 2 (ITV) 61, Mux A (CH5) 55, Mux B (BBC 4 etc) 58, Mux C (Sky 3) 57, Mux D (Virgin 1) 60.

Although channels 42 & 45 are used from Dover, DTVG do not mention these for normal reception. One likley problem you may have is interference from the continent. With the old analogue you knew when you had co-channel interference (the old "venetian blind" effect) on the picture. Unfortunately digital doesn't give you these clues.

[Jay6]

I live in Margate, postcode CT9. I think dover is my nearest transmitter. ..i'm doing all this on my phone's wap service though, its pretty limited and kinda fiddly, lol. ..I'd be very grateful if someone could confirm that it is indeed dover.

---------- Post added at 20:11 ---------- Previous post was at 19:55 ----------

Thing is though, i'm not sure if the group thing matters. When I scan my box, all the channels are found, and appear in the channel list. But in a nut shell, my ability to view any channel is never reliable. Sometimes I can watch, other times not. So i'm thinking that i just need to increase the signal. Would a better quality high gain aerial with a mast head amplifier fix this?

These are the results for your postcode area, using Wolfbane's digital TV predictor:

http://www.wolfbane.com/cgi-bin/tvd....L&HT=10&OS=ct9

Screencap attached below.

Essentially you do not have to have a wideband aerial for digital in Margate. This is good news in your situation for the reasons posted above by nodrogd. However there's a catch - there are two transmitters on the same site at Dover. The Dover transmitter requires a Group CD aerial; Dover B requires a Group E aerial. And Dover B does not carry all the muxes. There are all sorts of combinations of things that could be wrong here - you could be tuned to one transmitter but using an aerial intended for the other transmitter's group, for example.

Go into your loft and look at your aerial's nose. It should have a coloured plug in the end. The colour corresponds to a group as follows:

Group / UHF channels / Colour

A 21-37 Red

B 35-53 Yellow
CD 48-68 Green
E 35-68 Brown
K 21-48 Grey
W 21-68 Black (Wideband)

Whether or not you have the correct group, it's very unlikely that your current aerial is up to the job. Wolfbane suggests an amplified extra high-gain aerial for Freeview in your area and that's bad news for indoor aerial installations. However if you really, really have to have an aerial inside your loft, you need to go out and invest in the biggest, meatiest aerial you can lay your hands on, and yes, it will have to come with a mast-head amplifier.

As you can't sniff out a digital signal by connecting the aerial to the TV and having someone downstairs shout to you as you move the aerial around in the loft, as you would with analogue, you are also going to have to make very sure that you're pointing the thing in precisely the right direction as well. The Wolfbane results will give you the correct bearing. Repeat the search on the Wolfbane site, using an OS grid reference for your house if possible, to get precisely the correct bearing, then take a compass up to the loft with you.

[nodrogd]

The best option is an aerial of the specific channel group your transmitter falls into. Wideband aerials have to be a "jack of all trades" and generally, to get the same amount of signal from a wideband aerial as you get from a grouped, you have to almost double it's size. So for example to get the same gain as a 9 element Group C/D I would need a 16 element wideband.

Pre switchover transmitter powers are very restricted and susceptable to interference from existing analogue services, and as far as you are concerned continental services as well.

It's nice if you can DIY it and get a good result, but there are so many factors in play here. A decent CAI aerial installer with the correct test equipment and a knowledge of local problems is sometimes the most cost effective solution to a problem.

[Jay6]

Thanks very much for all that! Much appreciated! Right. I've been up there and had a look. The coloured part on the tip is brown. ..so that means its a group E aerial, and you say that dover siteB doesn't carry all the mux's. So, if i've understood all this correctly, that explains why i have never been able to view certain channels, and the weakness of my cheap aerial explains the unreliability of the others. ....so, as dover siteB doesn't carry all the mux things, I should be looking to get the biggest, baddest, high-gain group C/D aerial I can find, with a mast head amplifier. Is that my mission as it stands?