TV aerial advice

[Quigs]

Just about to replace the TV aerial at home as the current one isn't quite up to the job for the freeview signal, (have to boost it).

There seem to be a wide array of aerials available, and they say for strong signal areas, or weak signal areas etc. Is there anyway I can find out what type of area I am officially in - GU24, or should I just buy a weak signal area like at

because it covers all the bases?!

Also what is the most appropriate co-ax to use - as I am building my extension I need to wire to all my new rooms, but should I use just standard co-ax as at

is there a better alternative?

^^^^^^^^^^^^^^^^^^^^^^^^^^^ Gary Quigley See my build at

[Andy Hall]

be a much better choice.

If the signal really is poor, then you could use

have two of these and they are excellent.

You could perhaps use an antenna for the channel group of your transmitter, but you need to determine which transmitter it is first

GU24 is a large area, but somewhere north of Guildford, yes?

Take a look at the antennas on neighbouring houses. At a guess they are probably with elements horizontal and pointing towards London.? If so, then the transmitter is Crystal Palace and you could use a group A antenna. If the antennas have elements vertically arranged and pointing towards Guildford, then it is the relay station there and a group B antenna is needed.

The wideband type would be suitable for either.

be suitable.

Don't use the TV coax at all - it is rubbish.

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[tony sayer]

In article , Quigs writes

A pragmatic approach would be to go for extra gain in case your in one of those areas described as a "Pocket of poor reception" i.e. you might be screened by a rise in the ground towards the transmitter or screened by buildings etc. Best bet is to find out what aerial group other people use in your locality. If they are all within a particular aerial group then go for that one, only if you have widely spaced channels then you need a wideband aerial. Bear in mind that there is a gain/bnadwidth trade off with the conventional TV aerial. I'm not sure of the make of that one on the site, but I'd go for a UNIX or Thelves. Avoid Maxview in my opinion..

Also very important!!, use a satellite grade cable like CT100 not that junk they call low-loss found in the DIY sheds.

Try to get the aerial up in the clear and as high as reasonably possible. Check with some neighbours to see if they are getting good reception on digital and note if there are very elaborate aerials on very tall masts in the locality, a sure sign of bother!..

Happy erecting;))

[AndyM]

Agree but the picture greatly improved with the junk cable when I soldered all the connections.

possible. Check with some neighbours to see if they are getting good reception"

After time on the roof pointing the aerial in the same direction as all the neighbours I found that I get the best picture on channels 1-5 with the aerial

180 deg out from everyone else. There may be a new & better mast erected.

AndyM

[Richard Porter]

Is your aerial outside? If not just relocating it may solve the problem.

Don't buy a sensitive aerial if you don't need it. I haven't got an up-to-date catalogue but the one I have gives you a choice of 18 element or 43 element aerials in different band groups. Ask the local TLC branch (Guildford) which one you need.

You don't need satellite cable. Just get standard low loss 75 ohm co-ax which is available in white or brown. However you should be thinking about getting a distribution amplifier if you want to serve several receivers at once.

I would take the main aerial feed to the digital terrestrial receiver (DTR) and video recorder (VCR/DVD/ect.) and then feeding the output signal via the distribution amplifier to all the rooms. That way you can watch digital channels and pre-recorded material on analogue TVs without having to buy lots of extra kit. You'll only need to tune the TVs to the output channels of the DTR, DVD player/recorder and VRC as appropriate.

[tony sayer]

In article , AndyM writes

One would assume your being a good D-I-Yer at this, not a so called professional;)

Hope you mean transmission mast!. Actually I have known pro broadcast riggers, the £1000 a day guys screw up sometimes and reverse the elements or assemble aerials arse about face so they work better the other way round;!.......

[Andy Hall]

Requirements vary quite a bit within a given locality depending on the immediate surroundings. A store is only going to be aboe to say which they generally sell.

The OP indicated that he has poor results, so at least a higher gain and more directive antenna is probably indicated.

CT100 cable is certainly recommended for DTTV because the signal levels are substantially lower than the analogue channels. Cheap TV coax is not appropriate for DTTV for this reason, because it has poor loss characteristics with frequency and is susceptible to interference.

However you should be thinking

Only if the signals are clean and of suitable level first. A distribution amplifier should not be used as a means to increase signal level from a poor antenna and feeder - it will amplify the interference and contribute to noise.

.andy

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[tony sayer]

In article , Richard Porter writes

Well if the original posters aerial is the wrong type then he will need to replace. If it is in the loft or other adverse location but otherwise correct then moving it outside may well result in an acceptable signal level.

You very rarely ever have too much signal. Its always best to have more then you need to overcome variations in received signal level that can and do occur. Trees for example can have a very severe effect on TV reception both analogue and digital. This can be fine in the winter months but come summer, it can all go to a blank screen;(

Wrong advice. The grade of cable that is generally sold as low-loss TV cable is usually of very poor quality, with a poor braid weave that will leave the cable insufficiently screened. A good quality SAT grade cable like CT100 has a copper foil wrap and is better screened and much less lossy. The price difference isn't that great. I've used it for all out TV and radio aerial systems and its a worthwhile investment!.

Use a distribution amp if you DO intend running more than One TV off the system...

If you do that then take care not to have the output of the DTV receiver on a channel that is used anywhere in the area, otherwise signal beats can and do occur, and screw up the results.

Further interesting reading can be read on www.wrightsaerials .co.uk Mr "aerial" himself:))

[tony sayer]

In fact here is a well written article about TV aerial cables...

[Andy Hall]

worse per 100m at the top of Band V than CT100.

I notice that he has taken care not to bend the cables on the head end too sharply....

.andy

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[John Rumm]

This will show you:

digital TV there is a usefull reception predictor here:

can get your OS grid reference from

Good advice, also make sure you use a few joins as possible as well. Use F-Connectors on everything you can rather than the old Belling-Lee style TV Co-Ax plugs, and make sure everything (amps, spltters, wall ports etc) are fully screened.

[tony sayer]

into account the losses involved. For those of a technical bent and who wouldn't be, and for the waydio hamsters here this prog by Roger Coude is the dogs doodahs for this sort of thing:)

>For digital TV there is a usefull reception predictor here:

Well do yer know I haven't yet seen a telly or a DTV box with an F connector on, do they exist?...

[Richard Porter]

[Richard Porter]

I only said "if you don't need it". The OP may well need a high gain aerial.

Yes. A distribution amp is for that purpose. If you need to boost a weak signal then a masthead preamp is more appropriate, but it won't compensate for a poor antenna.

[John Rumm]

Not seen one, hence my "on everything you can" qualification above ;-) You can certainly get amps, splitters, and (if you must) wall plates with them though. The screw on ones are also a good deal quicker to fix!

[Andy Hall]

Exactly, and asking in the electrical wholesaler's is not going to tell you.

If the signal is weak, a higher gain or multiple antennas are preferable to a masthead amplifier.

.andy

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[Richard Porter]

Indeed. An amplifier can't put back what you've already lost! The advantage of the preamp is that you boost the signal at the aerial so it suffers less degradation and interference in the downlead.

[Quigs]

Thanks - all looks like sound advice!

Yes we are North of Guildford - Bisley in fact. The aerials do seem to point to London rather than Guildford.

Unfortunately I can't really judge aerial types by what the neighbours have, as shall we say the neighbours are all pretty elderly as are their houses and TV aerials - I doubt they even know digital telly has arrived - they certainly don't have Sky either ;-) No dishes to look at!!

[Andy Hall]

Agreed, but it's still better to put in a higher gain antenna than a lower gain one and a masthead amp.

.andy

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