Signal issues

finnie

Standard Member
My freeview checker is saying i should be getting 99 channels but in reality I am just getting a round 35, most of the time the reality is less.

The house is 5 years old and I have a cheap argos aerial in the loft. I do have an inline amp and then a amplified distribution box but i think the aerial could be my issue.

The checker states A and H Aerial groups, what does this mean?

I dont want to put an outside aerial up really
 

sbowler

Well-known Member
You could replace the loft Ariel with a more sensitive one. But an outside Ariel would improve things a lot.
 

A1944

Active Member
Yes, an outside aerial up as high as possible should be the answer. The checker is telling you what should be available with such an aerial, whereas with any aerial in the loft you are at the mercy of all sorts of issues such as metallic roof lining, tanks full of water, walls (maybe several if you are in a terrace).

The A H, refers firstly to the aerial group relating to the frequency band of your transmitter and, secondly, to the polarisation needed for the aerial, Horizontal or Vertical (referring to the way the main elements of the aerial are oriented).
 

Rodders53

Distinguished Member
LOCATION?
A nearby postcode (not your exact home address) will allow a rough prediction from Wolfbane and Freeview (UK spectrum planners) so we can give more accurate advice.

Lofts lose a lot of signal through the roof materials and/or gable end walls (typical estimates are 10dB loss that's 1/10 getting through cf outside in the clear). An aerial pointing through a series of party walls will lose a lot more.

A link to the exact aerial would help.
As would the make/model of inline amp and distribution amp.
An amplifier followed by another (amplified splitter) is generally deprecated and can result in having too much signal with similar results to too little.

Check all cables and connections are sound, properly terminated with no stray screening wires near/touching the centre cores. No crushed or kinked cables (replace damaged bits).

Use the TV signal level/quality meter to assess the signal levels on every tuned multiplex of channels?

Other things are to try by-passing some of the amplifiers and connecting one TV direct... but exact options will depend on what is fitted currently.


At the end of the day directional TV aerials, mounted externally and 10 metres above the ground are what the UK spectrum planners assume when designing the network of TV transmitters; so if you are not in a strong signal area it might be what you need.
 

finnie

Standard Member
A nearby postcode is HS2 0SU

My issue with an aerial is that I live half way up a hill and in one of the windiest places in the country. I would prefer not to have an aerial on the house but I could possibly put it on the garage, that would be a very long cable. I do have 5 coax cable in a pipe underground going to the garage as my original intention was to put a satelite dish on the garage. Would the long cable introduce any issues?

If i cant solve the issue then I may go down the freesat route. Needs a dish but due to the house orientation and direction issues this is easier to hide
 

Rodders53

Distinguished Member
OK so you are on the Northern end of the Isle of Lewis. That means predictions based on a postcode will cover a large area and therefore be much less accurate.

The actual terrain and obstacles from an antenna location will matter. But with what we have all I can do is give more generalised advice that specific.

That postcode gives two possible transmitters:

Eitshal - the 'main transmitter' on the Island, a 6 multiplex site - 37km (23 miles) away to the South-SouthWest.
Wolfbane suggests 37/40 dBuV/m depending on which mutiplex frequency at 10 metres above the ground (2 storey house rooftop), and that there is not line of sight to the transmitter, so signals will be diffracted.

Ness of Lewis - a relay 3 multiplex site - 3km (2 miles) to the East-SouthEast.
Wolfbane suggests 54 dBuV/m and clear line of sight at 10 m and less if the aerial is lower (e.g. a single storey).

Freeview predictions for interference from other transmitters are excellent from both the above transmitters.
Eitshal has "120 channels" whereas Ness Of Lewis is "45 channels".

Other postcodes for "nearby" post offices give similar results, although many suggest Eitshal as the likely transmitter when Ness of Lewis is probably a stronger and easier to receive signal?

You'll need to do your own runs for your actual address house number/name and postcode in Freeview, and the cruder postcode only for Wolfbane.

If you don't have a HD TV set the 45 from Ness of Lewis will be fewer. Check what frequencies are being tuned in and strored?
Check signal strength and quality readings for each one (list them here)?
Check which direction your aerial points: to Eitshal or to Ness of Lewis.

I need the exact aerial and amp details to be able to advise on them and whether the issue is one of 'wrong transmitter' or poor choice of kit or something else.

Long cables attenuate signals depending on cable type/spec and the frequency concerned: Coaxial Cable Specifications WF100 CT100 WF65 RG6 gives numbers.
Cable losses can be mitigated by using 'launch amplifiers', provided a good signal is received by the antenna (aerial). These can be remote (coax cable) powered if mains isn't available where the antenna is located.

TV and PVR tuners need around 45 to 65 dB signal in to work well (too much is as bad as too little). Aerials may have 10 dB gain and roof aerials 10dB loss so you can see Eitshal is probably not ideal (too weak inside the loft) but Ness of Lewis might be OK? Add a 20 dB amp, though, and then it might be too much and cause overload?
 

finnie

Standard Member
Wow thanks for an amazing response.

Its Eitshall we are tuned and pointed to. Cabling is ct100 but I am not sure about the type of aerial. As I'm not in the house right now I cant tell you either the amp or distribution amp either. I will try and remember tomorrow
 

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