[LINK] Digital TV could see viewers left in the dark [WAS: Digital TV, live in the clouds, you may not see it]

[David Boxall]

At 12/01/2008 4:26 PM Jan Whitaker wrote:
> http://www.theage.com.au/news/national/digital-tv-could-see-viewers-left-in-the-dark/2008/01/11/1199988590074.html 
>
>
> Digital TV could see viewers left in the dark
> Daniel Ziffer
> January 12, 2008
>
> TELEVISIONS across Australia could go dead in two years as analog 
> signals are switched off, with thousands of homes unable to pick up 
> the new digital system.
>
> A study has found that many apartment buildings that dominate the 
> inner suburbs are unable to receive digital signals as the December 
> 2009 date looms when the Government wants to switch off the old analog 
> system in cities.
>
> The world's tallest residential tower, the Q1 building on the Gold 
> Coast, is just one complex where residents cannot receive digital 
> television.
>
> The chief executive of commercial television industry body Free TV, 
> Julie Flynn, said the problem was extensive, but not insurmountable.
...
I've never lived in a high-rise, so I've no idea of the problems.  
Evidently, a lot of people (i.e. voters) are affected, so the problem 
will no doubt be given some priority.

Where I live (rural, with a mountain inconveniently positioned between 
transmitter and home) digital reception is usually better than 
analogue.  That said; when digital fails, it fails completely.  At least 
analogue degrades with some grace (and digital fails more often than 
analogue).

The causes of digital's fragility are difficult to determine.  
Sometimes, signal strength drops to zero.  Has the transmitter failed?  
Is something between transmitter and receiver blocking the signal?  I've 
no way of knowing.

I have noticed that poor digital performance often coincides with poor 
mains power quality.  Interference transmitted from high tension lines 
is enough to drown out reception on any receiver (mains or battery).  
Filtering the mains supply helps a bit, but the main problem is EMR from 
the lines outside the house.  So what is it that sometimes introduces so 
much hash into the mains supply that it causes such severe interference?

We certainly need some way of finding out what is causing interference, 
so it can be fixed.  I've no doubt there are people causing problems who 
have no idea they're doing so.  We also need some way of knowing if 
there's a problem at the transmitter, so we don't waste resources 
pursuing other suspects.  When more (or all) of the broadcaster's income 
depends on digital performance, maybe they'll get their act together.

-- 
David Boxall                    |  I have seen the past
                                 |  And it worked.
                                 |               --TJ Hooker