South Island analogue switch off, this Sunday 28 April

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#807984 30-Apr-2013 13:47

It was an all or nothing approach. Set Top Boxes don't have analogue tuners in them so to shift some services to digital and not others would have been a bigger problem. (Means most only have to learn one remote control :-) )

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knoydart

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#807991 30-Apr-2013 13:54

RustyViewer: I'm a bit confused. Why is there a "shortage" of space available? I thought the whole point of digital is to have room for hundreds of channels. I'm not talking about satellite here but terrestrial. So far, only UHF 32 & 36 are being used, aren't they? That leaves potentially heaps more space for other channels.

So far (in Chch from Sugarloaf), Igloo is on Ch 30, Freeview are on 32,34 & 36. World TV should be appearing on Ch 28 at some point. Sky (read Igloo) still have a number of conversion options which they have a couple of years to decided. There is also a TPP (effectively MTS) allocation at some point too so the transmission capacity is out there, especially using DVB-T2 like Igloo gives you some serious SD and HD capacity.

People just need to start running channels to get your 100's of channels of TV

jamesrobert

90 posts

Master Geek

#809348 1-May-2013 08:28

Interesting item

http://podcast.radionz.co.nz/aft/aft-20130430-1410-enthusiasts_re-discover_the_magic_band-00.ogg

richms

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#809678 1-May-2013 16:58

msukiwi: It was an all or nothing approach. Set Top Boxes don't have analogue tuners in them so to shift some services to digital and not others would have been a bigger problem. (Means most only have to learn one remote control :-) )

But they are not shifting, they have all been on digital for years now.

leave TV1 on analog running and most old farts who are clueless would be no wiser to the shutoff. Then kill the transmission when they start to all die out ;)

Richard rich.ms

tehconz

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#809689 1-May-2013 17:06

richms:
leave TV1 on analog running and most old farts who are clueless would be no wiser to the shutoff. Then kill the transmission when they start to all die out ;)

Maintaining an extensive nationwide network of ageing analogue transmitters so a couple of percent of viewers are not forced to upgrade is not an efficient use of resources.

richms

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#809694 1-May-2013 17:17

Leaving analog switch off till now is also not a very efficient use of resources, should have been done 2-3 years back, pretty much a month after digital came along.

Would be funny to have just looped the same coro street episode on analog for a few days and see if the oldies pick up on that or not ;)

Richard rich.ms

RustyViewer

296 posts

Ultimate Geek

#809695 1-May-2013 17:19

Maybe they're looking at the snow and thinking its a documentary about Antarctica.

Skolink

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#809757 1-May-2013 19:40

jamesrobert: Interesting item

http://podcast.radionz.co.nz/aft/aft-20130430-1410-enthusiasts_re-discover_the_magic_band-00.ogg

That is interesting (or at least the text article on the subject I found on the Timaru Herald website).
If it is a 'magic band' that can enable conversations with people as far away as Germany, and HAM radio transmitters are only a few hundred watts, how come TV1 transmitting at 200kW from the top of a mountain didn't drown out the band worldwide?

oxnsox

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#809772 1-May-2013 20:28

A number of reasons, amongst them: the bandwidth of the signal and the need for a large enough signal level to ensure quality levels of the transmission at the receivers tele..

Skolink

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#809790 1-May-2013 20:56

oxnsox: A number of reasons, amongst them: the bandwidth of the signal and the need for a large enough signal level to ensure quality levels of the transmission at the receivers tele..

I meant why didn't TV1 cause audible noise for HAM operators worldwide?

mattwnz

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#809793 1-May-2013 21:05

What really irks me about the switch off, is the lack of HD freeview throughout the country. SD freeview is worse quality IMO in terms of picture quality and compression problems, than a good analogue signal. Also it is a lot more expensive to get installed, especially if you have multiple tvs. Whereas hd freeview is built into every newer tv, and you can buy a uhf aerial for $50 if you didn't have one previously for prime. The government has made millions selling off the spectrum, so I think they should use that money to give more HD coverage. I kind of get the feeling that they are pushing people more to sky, as that is the only way many people will be able to get freeview in HD.

hdinsider

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#809800 1-May-2013 21:23

Bla Bla bla... 87% is enough dtt coverage. Get over it.

don't mess with me.... i'm the hd insider....

oxnsox

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#809816 1-May-2013 22:14

Skolink:
oxnsox: A number of reasons, amongst them: the bandwidth of the signal and the need for a large enough signal level to ensure quality levels of the transmission at the receivers tele..

I meant why didn't TV1 cause audible noise for HAM operators worldwide?

It may well have raised the local noise floor in places.... (Hams use very narrow bandwidths so would have noticed it as noise).. Also local users here absorb some of the signal (as they use it). Remember RF signal strength doubles on an inverse square law basis, which is why such high powered local transmitters are required to get strong enough signals just out into the local community

gareth41

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#809870 1-May-2013 23:48

Skolink:
oxnsox: A number of reasons, amongst them: the bandwidth of the signal and the need for a large enough signal level to ensure quality levels of the transmission at the receivers tele..

I meant why didn't TV1 cause audible noise for HAM operators worldwide?

No amount of power used will every get a radio signal beyond the horizon

grant_k

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#809879 2-May-2013 00:55

gareth41:
Skolink:
oxnsox: A number of reasons, amongst them: the bandwidth of the signal and the need for a large enough signal level to ensure quality levels of the transmission at the receivers tele..

I meant why didn't TV1 cause audible noise for HAM operators worldwide?

No amount of power used will every get a radio signal beyond the horizon

That's not always true, especially in cases like they were talking about in the Podcast. "Sporadic E" propagation uses highly charged portions of the Ionosphere to reflect VHF signals back to earth in a similar manner to what is routinely used for HF signals. Normally, VHF signals penetrate the ionosphere and go out into space, but sometimes during periods of high sunspot activity, or under Sporadic E conditions, they are reflected back to earth. I remember seeing Australian VHF TV signals interfering with local TV channels several times over the years when this happened.

Low-band VHF TV signals are very annoying to radio amateurs trying to use the 6-metre band in NZ. Channel 1 is used from Mt. Te Aroha, and also Mt. Kaukau in Wellington. The FM sound carrier of channel 1 is on 50.75MHz with a 75kHz deviation, and the NICAM sound carrier is at 51.1MHz with a bandwidth of 510kHz. The resulting multiple sidebands mean that the 50-51.5MHz part of the 6-metre band is still unusable in much of the North Island until analogue shutdown happens in December.

Also, the huge signal strength from local transmitters radiating 100s kW ERP is often more than enough to swamp the input stages of ham receivers listening for weak signals from overseas on the 52-54MHz part of the band. Soon, after more than 50 years, hams will once again be left in peace to use the 6-metre band as they see fit.

I can't help wondering what future uses will be found for the vast tracts of VHF frequencies that have been, or are about to become, deserted. They are capable of travelling for very long distances compared to cellular phone signals, yet the bandwidth is much more limited, so effective throughput is less. However, for slow speed telemetry, VHF can still be useful.

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