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 The birth of Television Australia, great read
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 Return to top of page · Post #: 16 · Written at 8:29:41 AM on 23 October 2019.
Robbbert's avatar
 Location: Sydney, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 1074

where did all these radio channels come from

I don't know, but I don't listen to any of them, I think they are a complete waste of bandwidth and taxpayers dollars.


 
 Return to top of page · Post #: 17 · Written at 9:52:14 AM on 23 October 2019.
Vintage Pete's avatar
 Location: Cromer, NSW
 Member since 1 May 2016
 Member #: 1919
 Postcount: 1050

Apparently and according to what I read in the news the Chinese have been buying up all our old AM frequencies here and in the Pacific.
Which I found interesting.hmmm
Pete


 
 Return to top of page · Post #: 18 · Written at 10:28:18 PM on 23 October 2019.
NewVista's avatar
 Location: MilwWI, US
 Member since 10 May 2013
 Member #: 1340
 Postcount: 600

main reason for choosing CCIR ..was..mains power frequency

An oldie but a goody .. with perhaps a little mileage left in it?
Can imagine the Euro lobbyists flipping Aussie committee with this one
-- just like they spooked Brazil into going with ridiculously incompatible 525/60 PAL


 
 Return to top of page · Post #: 19 · Written at 6:03:40 PM on 26 October 2019.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 1290

Hey Newvista, you will find in ALL cases and in ALL countries, mains power frequency and (analog) TV frame rate match. Consider why, back in the early days of analogue TV:

1. You are watching a Band 1 VHF channel and you are 50 or 100 miles or more from the transmitter. Nearby 11kV power lines have arcing insulators producing bands of noise in the picture. These bands will drift slowly up or down the picture but don't disturb the picture too much.
Now imagine the TV frame rate is 60Hz. Those noise bands will be rolling rapidly through the picture and will be most disruptive.

2. Early valve/tube TVs had smaller deflection angles and so the CRT would be affected noticeably by magnetic fields from the TV's mains transformer. If the frame rate was around the same as the mains frequency, you wouldn't notice it. Of course, CRT computer monitors would frequently use frame rates that were different to mains frequency but by then we had SMPS and the problem goes away - almost.

3. Many early TVs, either by fault or design, had a degree of visible hum modulation of the image. The same thing applies.

US tried very hard to push ASTC here for digital. But in the side-by-side tests with COFDM, the ASTC signal was embarrassingly fragile. Many free-to-air networks in the US lobbied hard to go COFDM but were pressured into accepting ASTC. And now there is ASTC 2.....

COFDM gives good results in areas where analogue TV was totally unwatchable due to multipath. My daughter lives in just such an area and I can attest to this. I find it hard to believe it can work so well, but it certainly does.

And PAL is SO much better than NTSC for colour rendition as far as the average user is concerned, because there is no need for a tint control. 20 or so years back I saw both in action on internal cable networks in educational environments.

Sorry to rain on your parade mate!


 
 Return to top of page · Post #: 20 · Written at 8:50:00 AM on 28 October 2019.
NewVista's avatar
 Location: MilwWI, US
 Member since 10 May 2013
 Member #: 1340
 Postcount: 600

"..4K televisions have been available for a long time, yet not one station in Australia broadcasts 4K.."

Just watched a Rugby World Cup game from TV-tech-fanatical Japan - something different about the picture quality..? Picture is smoother, less 'fatiguing'. I'll bet they are using 4k or better cameras as a source? Current broadcast cameras - even top line studio cameras - are still using those awful 2/3" 2k-pixel sensors (look up the specs of industry leaders like Sony & Ikegami.) Everyone knows you need to sample at, like, twice the desired resolution!


 
 Return to top of page · Post #: 21 · Written at 1:19:19 PM on 28 October 2019.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5500

I would assume they are broadcasting in 4K as they are currently running test transmissions in 8K. 8K, I'd imagine, is probably stretching things a bit - there's no reason why owners of smaller sets would need this and it'd be more suitable for screens in excess of 300cm or that ballpark.

I'd be happy if all Australian channels were in FHD. It looks good on sets ranging from 60cm to 200cm. I don't recall watching a screen that is bigger, though they do make them.


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A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 22 · Written at 9:13:24 PM on 28 October 2019.
NewVista's avatar
 Location: MilwWI, US
 Member since 10 May 2013
 Member #: 1340
 Postcount: 600

Well, you look at a typical live US NFL game: state of the art FHD, and, to be sure, the pictures they are working with from present day cameras are jazzed-up as much as possible (enhanced dynamic range and "sharpness") but there's a 'harshness' which is visually 'fatiguing' (confirmed by recent comparison view of RWC signal from Japan sourced with 4k or better cameras?)(a preview of upcoming Olympics from Japan, probably from NHK who have been prompting Ikegami to make better cameras!)

Digging a bit further into the specs of existing cameras, at Ikegami for instance they are touting "new 2.5m-pixel sensors" (not enough) (no doubt chips sourced from Sony) because the Horiz res spec is a meagre "1000TVL" for both theirs & Sony's cameras! Problem: weak competition in camera manufactures (a duopoly?) and shrinking broadcaster budgets.


 
 Return to top of page · Post #: 23 · Written at 10:29:45 PM on 28 October 2019.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5500

2.5 megapixels doesn't sound like much. I work at a hospital and it is a Dept. Health requirement that all S8 drug safes are protected by FHD cameras and the ones we have are 3 megapixels and can zoom in so what the nurses write in the log book can be clearly seen by the camera. They are top shelf stuff for a camera that fits inside the standard sized tinted domes. I would have thought that TV channels with million dollar budgets would be using something far better, given the price difference for a good quality security camera versus a broadcast standard TV camera.


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A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 24 · Written at 1:09:35 PM on 29 October 2019.
NewVista's avatar
 Location: MilwWI, US
 Member since 10 May 2013
 Member #: 1340
 Postcount: 600

"side-by-side tests with COFDM"

Does Aust DVB-T system allow 60p/60i source to pass through to viewers? (like for coming super quality Olympic pictures from Japan)
Have heard they can do this with Euro DVB-T.


 
 Return to top of page · Post #: 25 · Written at 11:22:27 PM on 30 October 2019.
NewVista's avatar
 Location: MilwWI, US
 Member since 10 May 2013
 Member #: 1340
 Postcount: 600

Well it's official, the 2020 Olympics will be sourced in 8k/120p video. This clip shows how NHK obtained the special cameras - if you freeze the video you can briefly see the brand HITACHI. They also show the home-brewed NTSC camera NHK used for 1964 Olympics and true-to-life 3683millimetre 8k screen.

https://www.bbc.com/news/av/technology-29789468/tv-technology-for-the-2020-olympics

NHK + Hitachi present world first:
https://www.hitachikokusai.us/BroadcastandProfessionalCameras/SK-UHD8060.html


 
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