Digital Aerial

[cheminot]

We receive french TV on a standard analogue aerial.

Our TV/DVD setup is capable of receiving digital TV and we can get some of the TNT channels but the reception is generally poor on these.

Would it be worthwhile changing to a digital aerial or is it just down to signal strength?

cheminot

[Tim]

Well there is no such thing a digital aerial. Aerials are passive things - they don't know or even care what sort of signal they are working with.

I can't answer your question about your current aerial. What I suggest is take a look at it - does it look old - how does it compare with your neighbours' - perhaps you need to install a larger aerial.

Generally, the digital transmitters are running on reduced power until the digital changeover.

Sorry I can't be too much help - regards - Tim

[Martin963]

Tim has covered the ground very well, so this next is really a bit superfluous.

Without knowing your exact location you're likely to be on the edge of the service area for Niort Maisonnay,  and if you're east of Cognac you might alternatively be getting a signal from Angouleme St Saturnin,  but as that one only transmits F5 and M6 in analogue it's unlikely that a single legacy home aerial would be pointing that way.

It's possible that a new aerial fitted well would bring in all the TNT's now,   but is there any point?   The power at Niort will be whacked up to 200 kW from the present 31 kW by Nov 2011 (maybe earlier for your region) and a coat hanger will probably work after that.

If you have a top-notch analogue picture at the moment then you might find that a cheap signal amplifier will push the digital channels up enough to render them reliable but it's the "amateur" solution so I wouldn't waste more than a few quid on that route and accept before you start that it might not work.    If your analogue picture displays with a bit of snow (graininess) or any ghosting then the aerial isn't doing it's job properly,  but will probably be OK after the power increase (unless your analogue picture is terrible of course).

Please come back if you need further help.

Laters:   I ought to add that before trying a signal amp you should verify that your aerial is pointing at Maisonnay, which would be roughly NE from you.    If you're using a non digital relay for your analogue your aerial might be pointing in the "wrong" direction for Maisonnay and the digital signals would be coming in off the side or back of the aerial which would make amplification less likely to work.     But I suspect you probably are using Maisonnay.

[cheminot]

Many thanks for your replies.

 I suspect my aerial is something of antiquity.

 It was on the house when we bought it so I dont know how old it is but it is definitely pointed towards Niort.

I think a replacement will be a good idea, has anyone got any recommendations regarding aerials please?

cheminot

[JohnM]

A lot of people think that there is a digital aerial, so just to reinforce what has been said earlier, this is how the "Digital Aerial" myth came into existence..

 

Good old fashion analogue signals are quite forgiving. Even if the signal your receive isn't as strong as "it should be" you can still get a picture. As the signal gets weaker the picture gets worse and it's almost a straight line graph. However, with digital, even as the signal gets weaker, the picture quality will stay about the same until it reaches a certain point, then the picture just breaks up. The signal strength that your aerial receives will vary depending on atmospheric conditions, the amount of leaves on your tree and.... sods law. So for some people, some days they get a good signal, some days they don't, some days it varies. So some days they get a good pic, some days they don't and some days the pic is fine for 2 mins then it goes, then returns and so on..

 

So..... as digital signals are not at full strength yet, in areas of weaker signal, aerial installers used to recommend and install, a "high gain" aerial. This had more prongs on it to focus and intensify the signal, they also used good cable and connections so that very little of the signal got lost on the way from roof to decoder. The householder would be told "you've got an aerial installed that will be fine for Digital...." which of course became "I've got a digital aerial".

 

So...... some aerials will pick up digital signals better than others, but as the guys have said, when the wick (power) is turned up on the transmitters, a lot of problems will go away.

[ventodue]

Just to say 'thanks' for all the postings in reply to cheminot's original post.  I have the same situation here in Montpeliier and was fairly sure it was just down to an old aerial, so nice to have it confirmed.

Amicalement

Craig

[Tim]

Glad the information was of some use.

Please guys, let us know how you get on.

Regards - Tim

[Martin963]

It's perhaps worth pointing out that one of the (many!) reasons why some people can't get TNT is because their aerial is pointing (correctly) at a relay station (analogue) which fills in a specific coverage gap in the analogue network.   Very few of these relays are equipped to transmit TNT - yet.

Now sometimes these gaps are quite small,   and may still have patchy (but unpredicatable) reception from the main parent station for the area,  which in most (but not all) instances is already carrying TNT.

So if one is really desperate for TNT it is sometimes possible in these circumstances to put up a high gain aerial at a good height pointing not at the relay but at the more distant main station, which is thus able to pull in the main station (equipped to transmit TNT) and thereby "jump the digital queue".    However this option should only be undertaken after seeking expert local advice,  as it could be expensive and is by no means guaranteed to work.

The point of digital switchover is to extend digital (TNT) coverage to virtually everyone;  however,   whilst the analogue network with its 3500 relays is still in operation there are simply not enough channels (ie frequencies) to go round without the two systems adversely affecting each other.  That's why a definitive switchover is required eventually.

So it may be for the Montpellier case that either St Baudille (the main station) is not giving you enough digital signal strength to keep the receiver happy,   or that your aerial is using (pointing at) one of the relays of St Baudille which has yet to be upgraded for digital.

It's likely that almost all the existing relays will be converted (apart apparently from some of the small town relays which are there to combat multipath problems in the analogue domain,   which it's thought will not be necessary for digital coverage) so if TNT isn't possible at the moment it should become easier by the end of the switchover process;   in addition the main stations' powers will be massively increased once the risk to the analogue network is eliminated by its closure.

[Jonzjob]

Our 'digital' areal is about 20 + years old and pointing towards the Pic du Norr on the Black Mountains, North of us. As has been said it is the same as any other areal for the analog system and it works very well. We too get 'drop out' occasionally which is the signal degredation caused by atmospheric conditions such as heavy rain or snow, the wrong leaves on the line, sorry, slipped to British Rail there! Trees blowing about, but no real problems.

We have had to resort to switching back to analog a few times and the difference is very noticable, but that is a rare occurence. It may be that your areal doesn't have a clear view of your transmitter and you may have to put your ateal on a pole to gain height?

[ventodue]

[quote user="Martinwatkins"] <snip>
So it may be for the Montpellier case that either St Baudille (the main station) is not giving you enough digital signal strength to keep the receiver happy, or that your aerial is using (pointing at) one of the relays of St Baudille which has yet to be upgraded for digital. <snip>
[/quote]

Ta Martin.  People tell us that reception here in Montpellier is known not to be good - and, if the signal's coming all the way thru the hills from St Baudille, I can understand why!  It seems the way to go is a TNT /internet/phone deal; but we couldn't get our Orange TV box to work, so have stuck with a simple decoder.  We'll be moving shortly, anyways, and I guess I'll sort things out then :-)

Amicalement

Craig