General aerial questions.

[djfonti]

Hi all.

I have an aerial in my loft that I've never used. It feeds in to all of the bedrooms. Got a new TV coming soon and want to take advantage of the built in freeview tuner.

I have tested the aerial with an old Freeview box I had lying around. I managed to get a signal after a retune, but no channels 1-8. I have read this may have something to do with it being an old box.

What I want to know is whether the aerial is capable of more. The signal was around 30-40% but fluctuated and on some channels it didn't have a signal when I checked later. The picture quality seemed fine when it worked. I think the aerial is plugged on to some sort of splitter or amplifier, definitely something that needs mains power. If I had a direct cable coming from the aerial itself, with no other lines and it wasn't feeding through anything else (as in the splitter/amplifier), is it likely the signal would improve? I only need one line off it so if that could significantly improve matters it will save me having to get a completely new aerial installed.

Thanks.

 

[kjhskj75]

To answer this question we need to know which transmitter your aerial is pointing at. Go to http://www.digitaluk.co.uk and enter your postcode into the form at the right. Check the box marked "I am in the aerial installation trade".

This will give a screen showing the transmitters you can receive from. Ideally you want one with 6 pairs of green bars.

It would also help if we knew which sort of box you are using. (there are lists of ones that no longer work).

Which of the following channels do you get: ? BBC1, BBC4, ITV1, ITV3, ITV4, Dave.

 

[Peter Rhea]

I think the aerial is plugged on to some sort of splitter or amplifier, definitely something that needs mains power. If I had a direct cable coming from the aerial itself, with no other lines and it wasn't feeding through anything else (as in the splitter/amplifier), is it likely the signal would improve?

If you can post a photo of the splitter/amp or a link to a similar item, it would make things clearer. Loft aerials can be difficult to optimise for all channels.

 

[djfonti]

Thanks for the replies guys. I will get the photos/details and update soon.

 

[djfonti]

Ok, I've been up in the loft and taken some pics.

To answer this question we need to know which transmitter your aerial is pointing at. Go to Digital UK - Home and enter your postcode into the form at the right. Check the box marked "I am in the aerial installation trade".

This will give a screen showing the transmitters you can receive from. Ideally you want one with 6 pairs of green bars.

Here are the results

It would also help if we knew which sort of box you are using.

Alba STB2NS/B

AS for which channels I get. I have just reconnected the box and there was no signal. tried a retune and the same thing - odd. From memory, when it did work last time, it was pretty much all channels except for channels 1 - 8, but like I said, a couple that were on the EPG were sketchy where the signal fluctuated.

If you can post a photo of the splitter/amp or a link to a similar item, it would make things clearer.

Thanks all. I am guessing due to the fact that I couldn't get a signal this time around it doesn't bode well?

 

[Rodders53]

Is the aerial connected to the cable going into the rhs socket of the amplifier?
Where does the disconnected cable go? (If it was the cable feeding the outlet you tried no wonder it didn't work ;-) )
Is the amplifier actually powered and warm (if cold it may have failed).

Is the aerial pointing to Crystal Palace (London ITV) to the West? or Bluebell Hill (Meridian ITV) to the South-Southeast?

Have you tried tuning in with an analogue TV? Which channels do you get? Which regional variants of BBC news and ITV?

I suspect your aerial is pointing to Crystal Palace and, although analogue works OK, the Freeview signals are not good enough (as per the poor predictions). It will almost certainly be OK after switchover though if analogue reception is OK now.

 

[djfonti]

Yeah, the cables are all correctly connected, I haven't changed anything since last time I used it (when it worked). I think it might be an issue with the box itself, which judging by the reviews online is rubbish. The disconnected one pictured I've no idea, I only saw it myself today.

I think it is facing towards Bluebell Hill but am not certain. When I tried tuning in analogue I got crystal clear pictures for 1-3, but channel 4 was unwatchable really, picture was fuzzy but audio was there.

I am thinking of persevering with my satellite connection for now, and laying some coax for the future that an installer can couple on to in the future if I decide to get a new aerial. Or I personally can connect to with this existing aerial after switchover (to test). I have to lay the cable now because I am re-decorating and laying new floor down, so would it be OK to use regular coax (WF100) for this purpose?

 

[kjhskj75]

Channel 4 at Bluebell Hill and the BBC & ITV Muxes are"out of group"compared with the others, which probably accounts for your bad reception.

You could get a "wideband" aerial, but things should improve when you switch over in June.

 

[kjhskj75]

More detailed reply:

BBC1, BBC2, ITV analog are on channels 40, 46 & 43.
Digital Muxes B, C & D are on 45, 42, 39
All these are covered by a "Group B aerial" which handles channels 35-53

Channel 4 analog is on 65, Digital Muxes 1, 2 & A are on 59, 24, & 27, all out of group.

but after June channels used will be 46, 43, 45, 39, 54, and 40, all within your aerials capabilities.

 

[djfonti]

Thanks for the considered reply kjhskj75.

I'll be honest, I don't understand the technical aspects too well. Do you think it is worth waiting to switchover and trying then? If so, would it be better to connect direct to the aerial and bypass the amp? Is it hard to to connect a cable to an aerial?

Sorry for the daft questions!

EDIT: I note you said I could use a wideband aerial. What are the chances of this doing the trick? Would something like this be appropriate?

http://www.amazon.co.uk/dp/B000NH85...de=asn&creative=22206&creativeASIN=B000NH8516

Could you please recommend something that you think would be good if not the above?

 

[kjhskj75]

Yes, I think that aerial would do the trick. (But other, more knowledgeable people on the forum may disagree.)

Given your proximity to the transmitter and that you only want to feed one TV I would guess you wouldn't need the amplifier. It was probably installed so one aerial could feed several rooms, rather than because of you having a weak signal.

It's my guess your existing aerial has been up there for a long time, probably since before Channel 4 started in 1982.

 

[grahamlthompson]

Thanks for thhttp://www.avforums.com/forums/freeview/1556612-general-aerial-questions.html#post16010207e considered reply kjhskj75.

I'll be honest, I don't understand the technical aspects too well. Do you think it is worth waiting to switchover and trying then? If so, would it be better to connect direct to the aerial and bypass the amp? Is it hard to to connect a cable to an aerial?

Sorry for the daft questions!

EDIT: I note you said I could use a wideband aerial. What are the chances of this doing the trick? Would something like this be appropriate?

SLx 27884D 48 Element Digital TV Aerial: Amazon.co.uk: Electronics

Could you please recommend something that you think would be good if not the above?

Get a log40 like this one

Vision Log 40 Aerial, Simplyaerials

If you are still short of signal add a masthead amplifier kit

eg

Vision 1 Way Masthead (15-27dB) + PSU (Vision V20-1127 KIT)

 

[djfonti]

Cheers for the suggestion Graham.

Is there any specific reason why the one you suggested is better than the other one? Like I said I'm not up on the technical stuff, but have you made the suggestion based on the information I provided (in the picture above) or is it just because it is considered a good aerial?

Also, how would I fit that one, doesn't look like it has a bracket or pole attached to it?

Doubt this is relevant but here is a pic of the current aerial

 

[grahamlthompson]

Thats a cheap and rubbish contract aerial. The log-periodic will have a way better performance and unlike the Yagi wideband has a very flat gain. This makes them ideal for use with amplifiers.

More reading

ATV`s Choice Of Aerials for digital TV

TV Aerial Tests

 

[djfonti]

Right I have read up a bit from the links you provided. They seem to be well rated. Easy to wire up, how about installation? Would it be as simple as getting a loft spike, fitting that, and screwing the aerial to it? Does alignment matter?

Also, as it is a wideband aerial, will this solve the 'out of group' problems kjhskj75 mentioned?

 

[grahamlthompson]

Right I have read up a bit from the links you provided. They seem to be well rated. Easy to wire up, how about installation? Would it be as simple as getting a loft spike, fitting that, and screwing the aerial to it? Does alignment matter?

Also, as it is a wideband aerial, will this solve the 'out of group' problems kjhskj75 mentioned?

You simply need to know how to fit f connectors.

Forget the grease if it's indoors

How to fit F Connectors to coaxial cable for Sky and Freesat

It should mount on your existing mount (mine's hung on a piece of string in the loft).

Yes it's a wideband so covers the whole uhf band 21-68

 

[Rodders53]

That is not a contract aerial as the reflector is made up of individual elements rather than a punched aluminium plate - but nor is it a top quality aerial, either. {looks a lot like a Blake SR ??? http://www.blake-uk.com/sr.aspx }

The way the aerial connector/dipole is attached looks dodgy - if not 'wrong' - and may be contributing to a poor performance. You also seem unsure if the amplifier is doing anything useful.

I'd try first, checking and re-fixing the dipole onto the aerial boom; next try joining the aerial cable direct to the TV via a joiner / coupler; next re-connect the amplifier to see if it actually works. Only then consider spending out on a new aerial.

It's highly likely that at Bluebell Hill's DSO in June next year all your problems will vanish due to: 1. the frequencies used will be received better by your aerial if it's not a wideband or group E but an old group B, and 2. the power increase from 2-3kW per mux to 20kW each will help enormously

 

[djfonti]

Thanks for the help Rodders and Graham. Really appreciate it.

Right, got some thinking to do. It is a lot of work because the loft is a mess....no boards, overflowing insulation, old air heating pipes, beams everywhere and spiders.

I fancy giving it a go just to learn but with all that testing to do even before installing a new aerial I am starting to think it isn't worth it. Waiting until switchover to see if things change on their own seems like a smart move, it's not too long away.

If I were to wait until S/O and install a new (better) aerial, I'm guessing the likelyhood is that I will get a good signal even in the loft?

 

[kjhskj75]

If I were to wait until S/O and install a new (better) aerial, I'm guessing the likelyhood is that I will get a good signal even in the loft?

I don't think there is any need for you to do BOTH. Either wait for switchover OR get a new aerial.

 

[djfonti]

Thanks guys, I have some thinking to do. Will update if I need any help if I decide to install.

Cheers.