8 replies to this topic

[mgaleano]

Hi

Take a look at the maps.

http://maps.google.c...mp;source=embed

Where do you think they could locate the repeaters?

I think we can start with the where the TV repeaters are. Definitely the northern beaches it is needed.

Is there is a requirement for Kings Cross? Did not test my digital radio out there? Again the Oatley area is it a need there? Or would a "C91.3" transmitter cover that zone.


Where would it be best to put a repeater to cover western Sydney? Would using the existing tower at WS FM (Winmalee tx) to cover the Kellyville, Windsor , Penrith etc area ok?

The southwest of sydney similarly could use the WS/ C91.3 tower location (Razorback).

The Wentworth falls tower could be used also to cover those spots around North western areas.

I would assume they could make the power a lot more than the WS FM repeater, perhaps a similar level to C91.3 or 96.1 The edge.

I'd be interested to know your opinions to make this DAB+ thing at least cover the area it is suppose to, much better than now.

Edited by mgaleano, 01 October 2011 - 09:23 AM.

[GlennP]

mgaleano, on Oct 1 2011, 09:20 AM, said:

Where do you think they could locate the repeaters?

I think we can start with the where the TV repeaters are. Definitely the northern beaches it is needed.

Is there is a requirement for Kings Cross? Did not test my digital radio out there? Again the Oatley area is it a need there? Or would a "C91.3" transmitter cover that zone.


Where would it be best to put a repeater to cover western Sydney? Would using the existing tower at WS FM (Winmalee tx) to cover the Kellyville, Windsor , Penrith etc area ok?

The southwest of sydney similarly could use the WS/ C91.3 tower location (Razorback).

The Wentworth falls tower could be used also to cover those spots around North western areas.

I would assume they could make the power a lot more than the WS FM repeater, perhaps a similar level to C91.3 or 96.1 The edge.

I'd be interested to know your opinions to make this DAB+ thing at least cover the area it is suppose to, much better than now.

The area it covers now is the area it's designed to cover, analogue radio is designed to have signal levels at the license area edge above a specific level, DAB+ digital radio is designed to have zero signal levels at the license edge, so it doesn't have overspill into the adjacent license area. You can thank Commercial Radio Australia for that.

TV from the Manly/North head site, doesn't reach much past Dee Why, so neither would DAB+ from there, & although patchy, DAB+ from Artarmon already services that area, a translator needs to be further North, or at the North end of the Northern Beaches, feeding back South.

The Napean/Hawkesbury river is the border for the Sydney license area, so anywhere outside of that wont be a Sydney DAB+ translator site, the whole reason DAB+ is patchy or non-existant out to the West is, it's designed/Engineered not to go out there past the river, if there were translators out there, they would be low power local area (1 or 2 suburbs) sites, otherwise it defeats the whole purpose of the power levels & downward beam tilt from Artarmon. Take the beam tilt off Artarmon & let the signal go & these western areas would be pretty well covered from the 1 site at Artarmon, so would likely the Northern Beaches areas, & the areas to the South West out to Campbelltown.

[alanh]

mgaleano,
DTV Coverage is better than DAB+ coverage because on the weakest signals its assumed that the antenna is 10 m above the ground and is a high gain type. This is hardly equivalent to a DAB+ radio in a metal roofed building using a short telescopic antenna.

Sydney RA1 Licence area This is for the high powered stations and there are other licence area maps for particular locations such as Campbelltown

Locations of current TV translators
Bombi Road BOUDDI for the Northern Beaches. This site is also used for the Central Coast.
Manly Sewage Farm North Head with a coverage area of lower Northern Beaches/Mosman
Elan Building Kings Cross with a coverage area of the CBD and Eastern Suburbs and some inner Western Suburbs.
Top Eastern Cutting RTA Bridge Approach WORONORA.

As GlennP has pointed out there is vertical tilt to prevent interference to and from SBS9A in Manning River and CTC 9A (Southern Cross) Bathurst. These transmitters ar both digital and vertically polarised.

In 2014 the Manning River and Bathurst transmitters will change channels.

The problem which will exist after 2014 is that only 8 DAB+ transmission channels ar available (currently Sydney is using 3), this is insufficient to prevent interference between DAB+ transmissions. If an SFN is used for the ABC/SBS programs, local radio cannot be put on that transmitter. So within range which will have to use different DAB+ transmission channels for Canberra, Illawarra, Central Coast, Newcastle and Central Tablelands. So this is one DAB+ transmitter for each area outside Sydney. There is no space for Cambelltown for example.

This is one of the advantages of DRM+ where there is 209 separate RF channels capable of carrying one or 2 programs/ transmitter.

AlanH

[lizclinton]

You really have to wonder if we wouldn't be better off with HD radio instead of DAB+. There would be no need for any new frequencies and none of the coverage issues that we currently have with this farcical situation of a Sydney digital radio service that cant be received in all of the Sydney metro area.

[DrP]

The US' HD radio is a dud.  At least DAB(+) is a widely accepted system.  Unfortunately its been rather hobbled in Australia by draconian 'anti-out of reception area' measures and services being run at too low a bit rate.  Poor reception and poor sound quality - the precise same reasons that caused DAB in the UK to flop.

[andrewlace]

Unfortunately that's the way it is.  It seems a little silly though as DAB is limited to those fanatics wanting to lift their AM reception.  Basically if you're in a home with a tin roof you'll end up with nothing.  Used a single channel amp and half band 3 antenna to retransmit for one store.  Basically, the killer here is cost.  The units are coming down in price but until they turn up 9A, its' still going to be problematic.

alanh, on Oct 1 2011, 03:13 PM, said:

mgaleano,
DTV Coverage is better than DAB+ coverage because on the weakest signals its assumed that the antenna is 10 m above the ground and is a high gain type. This is hardly equivalent to a DAB+ radio in a metal roofed building using a short telescopic antenna.


AlanH

[alanh]

Andrew,
This problem would not exist if regional and remote radio stations could go digital. The technology to be used is yet to be announced. Once this has occurred, Geelong, Latrobe Valley, Gold Coast, Sunshine Coast etc will get digital radio.

As I have said before, Commercial Radio Australia is well aware of the holes in DAB+ reception within their current licence areas. They just have to get ACMA licences, agree on who is to pay for the infrastructure and build them.

The choice for these services is between DAB+ for which 8 RF channels is insufficient and DRM+/DRM30.

AlanH

[DigitalRadioNow]

alanh, on Oct 1 2011, 02:13 PM, said:

In 2014 the Manning River and Bathurst transmitters will change channels.

The problem which will exist after 2014 is that only 8 DAB+ transmission channels ar available (currently Sydney is using 3), this is insufficient to prevent interference between DAB+ transmissions. If an SFN is used for the ABC/SBS programs, local radio cannot be put on that transmitter.

Perhaps all digital ABC Locals will be bundled and heard across all sites.

By 2014, we can only hope the proliferation of mobile internet streaming radios to be high to render licence areas to history. Unlikely as very difficult for the protectionist CRA to give up but it will happen. The better internet availability we have (esp via wireless), the closer this is to happening. Radio stations will have to revert to localism as their only hook for listeners who will be able to dial up endless choice of genres from across the world.

[GoForMoe]

As I've mentioned previously, there is a provision for a multiplex with a commercial/community/national radio split of 5/2/2 9ths, which would be the setup most likely to be used if an SFN model was chosen, with local radio/Coast FM being put on the 2/9ths allocated to ABC/SBS. It is certainly the only bandwidth efficient way to deliver DAB+ to regional areas without a compromise like in the Canberra trial.

I'd also add that starting DAB+ services is unlikely to be the end of the current coverage restrictions, while things like Brisbane's tilt to protect Wide Bay digital would be removed after restacking to clear 8A-9D, things like the Melbourne power limit towards Geelong are there only to protect the licence area (with Western Victorian DTV not much of a concern). I can't imagine a situation where those are removed, because even on a level playing field for digital, the current overflow (on FM/AM) is considered an anomaly by the local broadcaster, who would likely seek to continue to have the market covered without the intrusion into the local market area.

Edited by GoForMoe, 10 October 2011 - 08:36 PM.