ABC provided an overlap coverage map, mainly for certain areas suggesting an alternative transmitter.
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I’m interested when I go back to Swan Hill next week and see what feeds Goschen is receiving from the commerical stations since Bendigo is gone.
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Hi everyone,
Have been MIA for quite a few years but have been coming on to read sporadically,
Basically what I’ve been told by the techs was that yes there’s a ‘low power’ setup in place (forgot the name they usually call it), it’s not low power as such (running at 1kW) but was placed on a high up place in Bendigo, of which I forgot where but last I checked here in Melbourne, I couldn’t receive it.
With the television TX equipment, Amateur Radio Victoria have a DVB-T transmitter at Specimen Hill at 10w and is vertically polarised (callsign VK3RBO), have not heard anything from them in regards to the equipment at Mt Alexander.
In theory the DVB-T transmitter could be used, by rebroadcasting a single ABC feed from their off air satellite system (it could even be done from an Amateur Radio operators house), I say single feed since it’s at 10w you’d want to change the modulation to something which has more error correction and therefore can be received at lower signal strength therefore lowering the maximum bitrate, it could be bumped up in theory to 100w to allow further coverage. Most modern TVs can receive a DVB-T signal at 445.5MHz which is the output of the Amateur TV transmitter.
That said, I don’t know how ACMA (and the ABC) would respond to a ham rebroadcasting effectively commercial content and legislatively I don’t think there’s really any emergency provisions set aside to clear it.
Lastly, Mt Alexander is really the only suitable site for television into such a wide ranging area as Mt Macedon would get blocked slightly in the north west by Alexander on UHF, my honest opinion going forward if Mt Alexander can’t be used again would be to restack Melbourne to go to UHF and Bendigo onto VHF as you get slightly better penetration at a lower frequency, that said you might get some more spill of the VTV/BCV/AMV signal into Melbourne, also don’t really know how that would work with surrounding areas such as Western Vic which is on VHF but band planning is a very complicated task here in Australia, you also have the issue of having to turn a heap of rooftop aerials towards the new site, id be more inclined of a low power relay in Bendigo itself.
Thanks
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All very interesting @melbournefan Hopefully that low ish powered tx is sited on a hill south of Bendigo so most homes’ antennas are pointed the correct way. As in, towards Mt Alexander.
I’ve never understood why bandplanning allowed for so much UHF broadcasting in the bush when we all know that VHF travels further with less power. I know it’s complicated by only having seven VHF channels available for DTV. But it seems a lot of places without co-channels nearby would have been better served with VHF
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The low powered temporary transmitter was for 91.1, that’s my go to station when I’m around Melbourne as it bleeds in quite well.
Melbourne really doesn’t need VHF DVB-T, I once did a signal measurement on a TV in Ocean Grove years ago and everything was coming in very well. If there’s any issues in Geelong people could just tune to the SFN which still has good signal.
I think the regionals on UHF is more to do with preventing a situation like Sydney has with Wollongong and the regional signal bleeding into another licence area. Pre 2001 I think some channels on Mt Alexander were on VHF but moved onto UHF to accommodate for Melbourne’s DTV services starting.
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Given this map, I wonder if they can’t increase power a bit on those transmitters to try and expand who can get the other signals.
I would also suggest that their initial advice would be to attempt a retune and just see, before contacting an installer.
I assume the current situation is likely down to that people invested in UHF to get the extra aggregated channels - and then spent all of the first digital transition on UHF only, so many people would not still have legacy VHF equipment by the time of the restack.
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They wouldnt have satellite.. and yes a ham operator could do that but it would an against the conditions of his license and the conditions of the license of the repeater and as you said there no provisions for emergencies to do that and the ABC wouldnt know what amateur tv is and would 6 months before somebody would ok it. (the wheels of the ABC turn slowly)
Error correction (FEC) and modulation type are 2 different things.. I think you mean changing modulation to something less complex like QPSK with a higher FEC .. 1/2 for example so it can be received with a lower signal level.
I wouldnt say most TVs can receive 445.5 MHz.. I would say some would be more accurate.
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The issue you are up against is the DVB-T transmitters transmit ASI which is what comes out of the playout centre in Sydney - ASI is a combination of all the various TV channels and even some radio channels as well as the EPG etc. ABC and SBS have ASI up on the satellite and that is how they distribute their program. The same happens at the commercial TV but the ASI program usually gets to the high power transmitter site via a Telco service such as Telstra DVN fibre.
Transmitting a stand alone service if you just have a single SDI program source which is what comes out of digital studio gear requires a DVB-T encoder as well as the transmitter. In Australia the five main broadcasters use centralised playout for all their channels from a DVB-T encoders farm and send the appropriate ASI to each Class A and Class B transmitter site. Mt Alexander is a Class B and Dandenong is Class A. Most class C and D are translators but there are some still fed by fibre rather than off air from a high power site. The evening news and live sport etc go to the playout centres via a telco service and get switched up into the appropriate ASI channel via a routing switcher in the playout centre.
Most TV studios are just a newsroom, news presentation studio and a control room - some don’t even have the control room on site and are just a couple of remote controlled cameras and a set of microphones MUXed down fibre to Sydney or Melbourne’s control room.
There are other sites at Mt Alexander which are located some distance for the 2 sites damaged sites discussed so far. I’m not sure of that the status of those sites, but if any are operational they’d be preferable for any temporary setup since everyone’s antenna’s are pointing in that direction.
Do you know what brands of DVB-T encoders are in use in Australia? I’ve been reading about ETSI EN 300 468 a bit lately, but it’s hard to find what people are practically using instead of just what a spec says.
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Originally Tandberg were widely used as DVB encoders but the Playout Centres may have moved away from them after Cisco took over Tandberg. I will upload a section from the Harris DTV660 manual which gives a good overview of DVB-T. The Harris DTV660 is the most common low power transmitter out there
DTV660_Manual_General.pdf (3.0 MB)
DVB general description from Harris DTV manual - a good intro to DVB-T
DTV660_block.pdf (346.8 KB)
Block diagram of a LP DVB-T transmitter
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Although it lost the title during the digital switchover in 2010, when sections of the old analogue equipment were removed, the mast still stands an impressive 1,154ft (351.7m).
That makes it taller than The Shard in London, and a defining feature on the Lincolnshire skyline. Its bright red aircraft warning lights are visible for miles.
If you have a VPN there is an item on ITV News
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Television restoration update
Following assessment of the Mount Alexander site, BAI advises it can restore enough of the damaged equipment to return television transmission by late next week.
What audiences can expect:
- Most households who lost TV services will have them restored once transmissions resume.
- Initial picture quality may not be as strong as usual while reduced-power equipment is in place.
- There may be pockets of reduced or no reception, including parts of the Echuca and Daylesford regions.
- Quality and coverage are expected to improve in the weeks following restoration.
- BAI advises full restoration will take several more weeks.
- Coverage maps are below.
Important viewer advice:
Some viewers may need to re-scan their televisions to restore channels once services return. An antenna technician will not be required.
Radio restoration update
BAI is hopeful that all four ABC radio services (ABC Bendigo, triple j, ABC NEWS, ABC Classic) will begin to be restored from late next week.
What audiences can expect:
- Radio services will return initially with a much smaller footprint than usual due to reduced power.
- Coverage is expected to improve progressively over the coming weeks as further repairs and equipment restoration are completed.
- ABC Local Radio Central Victoria is currently on air on 91.1 FM. Listeners outside Bendigo can stay informed by tuning to ABC Wimmera on 594 AM.
- Audiences can also listen to radio services on the ABC Listen app and watch TV via ABC iview where internet is available.
- Coverage maps are below.
ABC Local coverage
ABC News Radio
ABC Classic
triple j
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Will be interested to know if all commercial services will be migrated to the ABEV/SBS BAI site on a temporary array, as the BCV site looked like a total loss from pics we have seen. No doubt EPP will be in fulltime use for a while too.
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I hope Indara isn’t owned by the same bloke that owned the Whyalla Smelter - Mt Alexander may be our first DVB-T2 site if it is.
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Time for a large photo dump…I went to Tamworth for the Country Music Festival and some sight seeing.
Old NEN-9/Prime TV studios on Goonoo Goonoo Road, kept in good nick
New 7 News Offices, with new signage.
Site of old NBN offices, now a Guzman Y Gomez - I do have an actual image of that here somewhere…
ABC Local Radio studios
Entrance - it’s at Parry House to the right of the main doors
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Representation of relevant media at the TCMF
iHeartRadio - can’t be arsed to staff it
88.9FM studio at the Atrium
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TMFM/92.9 Studios on the Goonoo Goonoo Road
The front
The driveway entrance
The actual entrance, and yes, the 92.9 banner really was like that
Smaller version of the Golden Guitar and a faux-old 2TM poster in the courtyard
Afore-mentioned sign
Signage in the courtyard
Timeline of the station - which would be an interesting read, had it not been blocked by the shrubs. It is on the website IIRC. Also, one of the tourism websites lists this as an attraction. Quite a low bar… 
Sign at the exit tooting their own horn.
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WIN and (apparently) Nine/NBN offices near the Harvey Norman building in Ringers Road.
Two things to note -
1 - the WIN Network signage has seen better days
2 - not one, but two NBN News Toyotas parked out the front. One of them had pulled up and the journo (can’t think of the name) and camera guy hopped out and entered the building,
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