People seem to
be dreadfully poorly informed about digital TV. At least those
who do not receive Satellite TV who presumably are badgered by
Sky to swap over from analogue. I see now that On-Digital are
going to spend some money on informing the public. Hopefully
the information will be assimilated and acted upon before the
analogue transmitters are turned off! Now that On-Digital will
be called ITV-Digital how is BBC going to fare and how will this
affect the appearance or otherwise of ITV on satellite? It's
starting to look more and more like the battle between the two
satellite providers Sky and BSB and then the battle for viewers
time on Astra. Does anyone remember the time when we had three
satellite sports channels? Screensport was taken over by Sky
and closed down. "There isn't room for that many channels
dedicated to sport". Having got rid of the competition they
expanded the number of Sky Sports channels. Eurosport and Bloomberg
are still free on analogue but you have to pay for them on digital.
S4C is free on terrestrial analogue but you have to pay for it
on digital satellite. Discovery used to be free, Children's Channel
used to be free....
Now I hear that ITV
is losing revenue. Not surprising as the lion's share of digital
viewers are told to revert to steam TV to receive ITV. As most
viewers don't understand how to use their TV sets they will now
skip trying to watch ITV and instead, look at an alternative.
Although ITV are leasing satellite space for ITV1 & 2 these
won't materialise until Christmas, I hear. They are caught between
a rock and a hard place... if they broadcast on "Sky",
as it would appear to most people, there's no chance of existing
viewers subscribing to On-Digital or now "ITV Digital".
All they can do now is wait until the terrestrial digital bandwagon
inexorably rolls towards analogue switch off and capture the
few remaining viewers who would NEVER switch to satellite. Loads
of people can't receive terrestrial digital yet and anyway the
satellite option is adding more and more channels, not only through
Sky, but also through new Eutelsat satellites that were originally
guaranteed that orbital slot at 28-odd degrees East. It seems
to me there are currently only a smallish group of viewers who
might take up the terrestrial option... viz. those that haven't
heard about the "free"satellite option; those who have
a tree in the way of 28 East; those who haven't got a telephone
point available; and those who will respond to On-Digital's advertising
without checking on their options.
What's going to happen
to terrestrial digital? One option is to give the whole show
to BBC. If they were then to then pull out of satellite TV taking
with them their TV and radio channels together with any other
channels they could persuade to leave, and maybe also ITV even,
then terrestrial digital would be in with a good chance of survival.
The real pull towards BBC is the absence of advertising and the
real pain with Sky is their boring, distracting advertising together
with their unwanted loss of program coverage when relaying say
golf from a US broadcaster (when they add their own huge amount
of advertising).
All-in-all the organisation
of digital TV broadcasting, I believe, is abysmal. It's even
worse than the start of satellite broadcasting when government
assurances weren't worth the paper they were printed on. Remember
the "squarial". Faced with absolutely overwhelming
opposition, the government "sponsored" D2MAC "official"
satellite broadcasters ended up pushing the shape of their dish
because that was all they had left. "I've got a SQUARE dish
and 6 channels"... "I don't really know what shape
my dish is but we've got 36 channels". BSB had no competitive
channels, too few channels, too specialised an equipment, and
a rotten orbital slot (over South America would you believe!).
They went bust, were swallowed up by Sky, closed down, and their
satellite was sold off to a Spanish concern at a knockdown price.
It's about time a professional
was put in charge of the whole thing and politicians wheeled
out to the sidelines before big business brings about their own
plan to the detriment of all but themselves. The slippery slope
is already under our feet. Sky have now introduced huge price
increases (175% that's one hundred and seventy five percent)
for their set top box "installation" for subscribers
because, presumably they see little opposition in the competition.
Next we may see price increases and restructuring of how channels
are paid for as they capitalise on their approaching near monopoly.
Since I wrote the above
ITV digital took over DTT, and after a short while went bust
due to inept management leaving FA Football Clubs reeling from
a budget shortfall.
BBC have taken over
the helm and because of their existing avenues for broadcasting
commercials for their own products, with the help of manufacturers
like Pace who made a set-top box at an economic price, telling
sort of big fibs by not mentioning the possible need for an (expensive)
new aerial, cranking up the power of digital transmissions against
the advice of the experts and changing the mode of transmission...
should make a go of things. Many people though are being hoodwinked
into paying nearly as much for "special cables" as
the box itself by big-name retailers, anxious to make money from
the opportunity.
Post script... it's now some years later
(October 2006) and "Freeview" is now commonplace, although
a good few people still haven't heard of it. "HD" or
High Definition TV is next on the horizon. This is basically
1000 odd lines instead of interlaced 625 (really 300 odd). I
haven't seen any examples myself, but I guess it goes well with
flat screen TV, which is quite capable of really good results
as it's been weaned on computers. Flat screen HD TVs are generally
very expensive, although some models are available at a third
or a quarter the price of the dearer models. Because HD uses
a lot more bandwidth it's a lot more expensive than ordinary
digital channels when it comes to subscribing.
Incidentally when it
comes to "lines", some viewers of new TV sets will
profess that they can't see any. Very large screen TVs employ
a method of scanning that shifts the position of successive frames
so that lines are effectively invisible. This is all very well
but the loss of lines results in picture definition way below
what is technically feasible, hence the need for something better
ie. HD. If only 300 different lines are used in a standard TV,
then on a screen 30 inches in height, the picture is viewed in
tenth-inch stripes (2.5mm) . Compare this to the pixel spacing
on a good quality computer screen, CRT or flat panel, and technically
you can resolve down to 0.15mm. In other words the screen can
accommodate a TV line scan of 5,000 lines. A 30 inch high flat
screen would need a pixel spacing of around 0.4mm for this scan
rate, or for 1300 lines for HD TV, around 0.6mm spacing.
Looking in the other
direction... I bought some new boxed VCR's for £10 the
other day and DVD/Hard drive recorders are available around £100
and prices will continue to fall until old stocks are exhausted.
This is because these models use analogue TV tuners. Good bargains
as a digital set top box is £25 and can be used as front
end to both an old VCR or DVD recorder. There are two drawbacks,
first is the set of three remote controls needed to make timer
recordings, and secondly the technical expertise needed to understand
how to use the system !
PPS... 2013 and analogue TV broadcasts
are no more. Digital TV rules.
Once again politicians
are looking for ways of remaining in power and seeking further
ways of making money.
Sell off the TV broadcast
spectrum was in vogue. Now its back in vogue and the digital
broadcast bands are being compressed yet again.
Not only in the UK but
everywhere.
Sadly it looks as if
HD TV without satellite or cable will be confined to just 4 or
5 channels, that is until the next leap forward in technology.
The problem with disposing
of Band V and stuffing everything into a truncated Band IV sounds
sort of plausible, but on the continent in areas demanding multi-lingual
broadcasting, the squeeze in spectrum seems not to be able to
provide enough space.
Thankfully CRT TV sets
are no more, although I don't admit to fixing domestic stuff
any longer.
Who would have thought
a 32" TV could be lifted with one hand. The last 32"
CRT set I had in the workshop took three of us struggling to
lift it onto the bench.
A couple of up-to-date
repairs. Well, they're up-to-date in 2015 anyway.
A Mercedes electronic
controller. This operates the electric windows and sunroof but
sadly it did neither, which was even sadder because at the precise
time it failed both windows and sunroof were wide open and it
was about to rain. So it was then, that the owner took his car
to our local garage, and being kind souls they sheltered it under
cover whilst they diagnosed the fault. I was presented with a
plastic-cased circuit board which I'd previously repaired for
a similar fault when the case got full of water and despite it
having been re-sealed more water had got in five years later.
Patches of grey once
cleaned away revealed a 7- legged chip. This had started life
with 8 legs but water and electrolytic action had eaten one completely.
On the case under a strong magnifier could be seen the numbers
290301, which after at least 40 minutes of puzzlement worked
out to be shorthand for LM2903AVQPWR, a tiny device some 3mm x 4mm
with 8 legs. After detaching the 7 legged chip and replacing
with the 8 legged chip the windows and sunroof worked a treat.
How many types of LM2903 are there? Looking at the manufacturer's
datasheet (click the number above) reveals there are 30 different
codes of this one chip. Choosing the correct one is important
because some are four times bigger than the one I needed!
The next day a faulty
computer power supply was on the bench. Not an ordinary PSU,
but a 200watt slimline job that cost nearly 4 times the price
of a standard version. The answer was to fit the computer into
a standard case with a standard PSU and dispense with the slimline
computer case and expensive PSU. I'd decided to check the old
PSU. Capacitors all OK even though I swapped some likely candidates.
Under test it just twitched and only the 5 volt standby output
was present. Inadvertently I connected the minus 5 volts to the
power switch input and oddly the thing came to life. Everything
was present but low voltagewise and in particular the 3.3 volt
output which read 0.168 volts.
I removed the 3.3 volt
rectifier having measured an anomaly then, after this tested
OK, removed the switch-mode transformer. This had a 5 volt winding
and a 3.3 volt winding, but the later was open circuit. After
breaking away the ferrite core and removing the outer high voltage
winding of 14 turns I removed the few turns of 5 volt winding
and discovered the 3.3 volt winding. This was copper tape and
one connection to the tape was fused open circuit. Sadly the
transformer was half the size of the normal type and the space
insufficient to mount the latter. Hence the decision to change
the case.
