Terrestrial Alignment

Dasilva81 · Sep 25, 2015

I am trying to align aerial in my loft, i am getting signal however not sure if it is enough.

Channel 23 - signal strength between 40% - 46%

Other channels are slightly higher in there 50's.

Is this enough, i will be connecting to a multiswitch and feeding rest of the house.

timo_w2s · Sep 25, 2015

A percentage doesn't really mean much. What are you measuring with to get these figures?

Dasilva81 · Sep 25, 2015

timo_w2s said:
A percentage doesn't really mean much. What are you measuring with to get these figures?

I'm using a revez stc-60 meter

satelliteman · Sep 25, 2015

Terrestrial off-air signal carriers or multiplexes are measured in dBuV or dBmV. You need a meter capable of measuring the average power. Percentage is not much use other than using it for peaking the signal.

Terryl · Sep 25, 2015

An antenna inside the attic (or loft in your case) will get about 1/3 to 2/3 less of the desired signals, it all depends on what the roofing materials are made of, why cant you mount the antenna outside where it will work a whole lot better?

And running the signals at that signal strength to a splitter or multi-switch without a pre-amp on the antenna will cause a sever loss of signal, unless the multi-switch has a terrestrial input that is amplified.

rolfw · Sep 25, 2015

As above, difficult to say with a percentage from a cheap meter, but quality is more important, as long as the signal is above the threshold of the TVs. Which multiswitch are you going to be using? Some have a considerable insertion loss on the UHF input, whilst others are zero insertion loss (they have a built in pre-amp), some will also have a 12v switchble supply on the UHF input, so adding a LTE filtered low noise masthead amplifier is easy.

Try connecting it temporarily straight to a TV which has a signal strenghth and quality reading.

Channel Hopper · Sep 25, 2015

Have you got the aerial pointing South East.

Is there a bigger building South East of you ?

Is your loft insulated ?

Archived-1 · Sep 26, 2015

Are you using the correct polarity ?.

Channel Hopper · Sep 26, 2015

Looks clear to the South East, the majority of the existing aerials look like standard ten elements.

in view are at least 18 element.

Terryl · Sep 27, 2015

Those roofs look like tile, very bad for an in attic antenna. (loft)

The only place may be outside.

Channel Hopper · Sep 27, 2015

Crystal palace is only a few miles from Neasden, putting out around 200kW on each Mux.

rolfw · Sep 27, 2015

Yes and most of the aerials in the screen shot above will have been installed pre digital switchover and prior to the massive increase in wattage. I've managed to pull in better than 42dbµ with a minilog in lofts from Reading using Crystal Palace and we're 40 miles away, the aerial does of course need to be pointing outward and not through the neighbour's loft.

timo_w2s · Sep 27, 2015

I must admit we get a good digital signal on a small 30 year old basic group A loft aerial in south Bucks looking at Crystal Place. Channel 5 in the analogue days was a bit fuzzy but the other analogue channels came in strong.

Terrestrial Alignment

Dasilva81

Regular Member

timo_w2s

Retired Mod

Dasilva81

Regular Member

satelliteman

Administrator

Terryl

Specialist Contributor

rolfw

Believe it when I see it Admin.

Channel Hopper

Suffering fools, so you don't have to.

Archived-1

Persona non grata

Channel Hopper

Suffering fools, so you don't have to.

Terryl

Specialist Contributor

Channel Hopper

Suffering fools, so you don't have to.

rolfw

Believe it when I see it Admin.

timo_w2s

Retired Mod