Wollongong-Syd-Newcastle 70cm repeater network

[VK2LK]

Hi All,

After having read the thread viewtopic.php?f=74&t=11112 regarding repeaters and their planning and usage, I want to know if anyone would be interested in using a large linked 70cm network that spans from Newcastle down to Wollongong, the Sydney metro basin and possibly even have a node down in Canberra. Such a network would be in line with the work that was already done in Sydney by a well known late HAM operator.

It's certainly possible that this network could be built (as we have the right people already involved) however given the massive effort that would go into setting it up, planning and co-ordinating frequencies and licenses etc, the real question is, would anyone use it?

Cheers,
Matt

[VK4TI]

Hi All,

After having read the thread viewtopic.php?f=74&t=11112 regarding repeaters and their planning and usage, I want to know if anyone would be interested in using a large linked 70cm network that spans from Newcastle down to Wollongong, the Sydney metro basin and possibly even have a node down in Canberra. Such a network would be in line with the work that was already done in Sydney by a well known late HAM operator.

It's certainly possible that this network could be built (as we have the right people already involved) however given the massive effort that would go into setting it up, planning and co-ordinating frequencies and licenses etc, the real question is, would anyone use it?

Cheers,
Matt

If ip access was available I have several friends I would like to chat occasionally down that way , it would be a definite plus for the community

[VK2LK]

Yep, anything is possible.

The idea is to increase activity and get more people on air first and foremost... If no one is keen, then theres little point putting the effort in, so everyone speak up!

Cheers,
Matt

[VK2FUND]

I know it would be the channel I'd have the radio turn on to every day. I often travel up North and the Central Coast as well as down South through the national park and to Wollongong.

Frankly I think it's a wonderful idea!

Cheers,
Ash

[VK4DU]

Go for it, mate.

[VK2XSO]

There is also the Kaputar link system which currently links Mt Kaputar 2m and 70cm with Glen Innes 2m and Tamworth 70cm.
To link the southern end of this network into Newcastle would be a fairly easy task for me to do if the guys one each side of the link wanted it.

I've also been slowly working away on a 23cm link from Tamworth 23cm repeater via Ebor to Mt Nardi 23cm repeater near Lismore.
But Mt Nardi isn't ready and it may be some time before it is.
I've surveyed a couple of 23cm paths to distant sites which may be possible in the future.

[VK2AAH]

Hi Matt,

My suggested system would combine the ACT-Wagga, ACT-Goulburn, Goulburn-Central Coast, Illawarra, and St George networks to form a single linked network consisting of the following sites (south to north):

Wagga
Mt Ginini
Mt Gray
High Range
Maddens Plains
Kurrajong
Horsley Park
GPT
Mt Penang/Somersby

It wouldn't be hard to extend it north to Sugarloaf and down through the Illawarra. It could also be easily extended south from Wagga into VK3 and north towards VK4 (either via the New England or the North Coast). Most of the infrastructure is there & I know one or two of the clubs may like the expense of running these networks to "disappear". No-one is suggesting there wouldn't be challenges but wouldn't it be a great network if it was done properly? By properly I mean digital hot links, low latency etc...

Cheers,


Richard
VK2AAH

[VK5ZK]

Hi Matt,

My suggested system would combine the ACT-Wagga, ACT-Goulburn, Goulburn-Central Coast, Illawarra, and St George networks to form a single linked network consisting of the following sites (south to north):

Wagga
Mt Ginini
Mt Gray
High Range
Maddens Plains
Kurrajong
Horsley Park
GPT
Mt Penang/Somersby

It wouldn't be hard to extend it north to Sugarloaf and down through the Illawarra. It could also be easily extended south from Wagga into VK3 and north towards VK4 (either via the New England or the North Coast). Most of the infrastructure is there & I know one or two of the clubs may like the expense of running these networks to "disappear". No-one is suggesting there wouldn't be challenges but wouldn't it be a great network if it was done properly? By properly I mean digital hot links, low latency etc...

Cheers,


Richard
VK2AAH

]

And just when are you calling a meeting and coordinating all this.

Talk is cheap. Action is another thig.

Having built the 1st VK5 2mx repeater in 1970, which is still on air today, and installed multiple 2mx and 70cm Packet repeaters in the 1980's I kow how much work is involved to make it happen.

Get out from behind the keyboard and do something.

If you actually achieve something I will be the first to congratulate your efforts. Good luck.

Garry VK5ZK.

[VK2AAH]

Garry,

You clearly don't know what I do for a living... and anyone who knows me knows that I don't just hide behind a computer. I don't think I need to defend myself to you ol' timer...

Cheers


Richard
VK2AAH

[VK2LK]

Guys, the purpose here is to discuss if people would use such a thing or if it would sit there idle like most of the other repeaters on air.

That is all

[VK2AVR]

Would be very interested in helping with something like this! Big project but with the right equipment and connections and a fair bit of work it is possible. A large area coverage properly controlled would be amazing.

I think the risk/reward is just something you have to evaluate and go and do it. Use the Wollongong / south coast link as an example. Does it work better than a single repeater? If so, the theory is sound. There will always be people who say they'll use it and never do, and those who pooh-pooh the idea and then when they realise how good it is they sneak on when they hope everyone has forgotten. I think it would be a great asset for amateur radio in NSW.

[VK4TIM]

ZL's National System is an example of how it could be done, very easy, and in band, and the controllers to run the system are very simple.
The only requirement for that is an inverted intermediate repeater, RX high and TX low, every second repeater in the chain.
Run the inverted nodes in areas of higher population density to get their receivers away from the LIPD interference, and use yagi antennas on the links. Any interference on one receiver will be heard across the entire network.

It would be an interesting project, and as long as there is a good path from site to site for UHF linking, (good fade margins, minimal over-water and unobstructed paths) it could be fairly easily engineered.

Linking by means of digital (say IP based systems over RF) links can introduce delays, which over a long system could become unacceptable. Digital linking systems operating at say 23cm could be employed as a backhaul, and equipment used in commercial links is available at around 1400 MHz and could be modified and brought into the band OK.
CTCSS could be used on links, but the decoders would need to be very fast (to minimise key-up delay across the network), and I would recommend using higher tones as higher tones often decode quicker. Re-use of CTCSS tones across the network probably not a good idea because of propagation along the coast during the summer causing interference.

Feasible project. I have experience with the ZL network.

[VK2AAH]

Hi Tim,

Thanks for the input- and I agree with all of your suggestions except for the in-band linking. That is the one criticism I have of the ZL network. I would look real carefully at other options if there are any- there are a few very smart microwave gurus interested in this challenge. Most of the link paths in this area are well known & tested, though High Range- Penang always amazes me... Lots of hurdles to be jumped yet but the guys concerned can count on my assistance if they want it.

I wish we had money for Mimomax digital links... seriously good performance in applications like this. Alas, I think I'm dreaming.

Cheers

Richard
VK2AAH

[VK2PR]

Yep, it's a fantastic plan Matt, go for it! I would use it everyday while I'm out and about.

[VK2XSO]

And just when are you calling a meeting and coordinating all this.

Talk is cheap. Action is another thig.

yes, but it doesn't take an committee to make it happen, it only takes one person to do something.
Whether others help or not is up to them.

I'd be prepared to stick my head in the lions mouth and say that I'd got more ham repeaters on air than Richard.
Most or northern NSW APRS digipeaters are on air because I put them there.
I'm lucky because I have the support of a fantastic club (Tamworth club) and I've put in lots of time effort and money into making it happen. Some notable mentions go to Graeme vk2jub and the Port Mac club.
And I have used my outstanding good looks and charm and probably even body odour (hams like that) to influence others to help out too. I've also been known to make hostile take overs and ignore some individuals and even clubs who obstruct development.

If I didn't think it would piss somebody off, I would find some time in the next week or two to link the kaputar system into either Newcastle or Rylestone repeater which I've heard is now linked into the south coast network.
One problem I am aware of with link systems is audio degradation, so each hop adds a little bit more noise and distortion. On long analog links it can cause problems. So that is my only technical caution with adding in a link repeater to the existing network.

I just thought I'd try total up the digipeaters I've put out there. It looks like there are currently 12 and about another 10 I've had my evil influence upon them as well as a few voice repeaters. And there would be a lot more with more support. It's amazing how much help even trivial things can be.

[VK2AAH]

Trash, no need to put your head in the lion's mouth on that one... all my experience is in land mobile, though my count over the years would be in the hundreds! Hey if you don't think I have experience I guess I'll just have to spend more time relaxing.

People should work together rather than turning things like this into a peeing contest.

Cheers

Richard

[VK3AIF]

Yeah I'd definitely give it a go when in range of it and I do frequent the Tamworth area around this time of year.

Also travelling the Newell a few times a year can be a pretty quiet time VHF wise and difficult to raise anyone on the few repeaters along there though I realise this plan is more to the East of that area it is still a good one.

[VK4DU]

What are you people on?

It was a simple question.... would you use it if it were there?

Yes or no?

Exactly........

YES.

[VK2AVR]

yes, but it doesn't take an committee to make it happen, it only takes one person to do something.
Whether others help or not is up to them.

People should work together rather than turning things like this into a peeing contest.

Agree x2!

[VK3YE]

(warning: armchair speculation follows)

A single channel FM repeater system is great for people driving up and down, but otherwise doesn't capture the imagination or encourage a lot of experimentation by users.

While considerably more complex, with much greater power requirements, wouldn't a chain of crossband linear translators with a 100 - 200kHz wide bandwidth be grand? It would allow multiple contacts on multiple modes, including digital and image communications. A far cry from the limited versatility of the standard FM repeater.

It could even be a use for the 51 - 52 MHz segment if we get it, though higher VHF/lower UHF frequencies would probably be more optimum and less noisy.

A problem is that unless the power output was very high the density of power on (say) a single SSB channel would be low. Which means that a translator might have a difficult time to extend range compared to direct contacts between even modest VHF SSB stations with say 25w and a 6 el yagi. (This problem was less with linear translators satellites due to the line of sight paths at both ends).

Users would also need to regulate their output power (or have some sort of AGC circuit applicable over sub-bands within the translator's passband) so that strong signals don't swamp the system and lower signals for the rest of those on it.

And I suppose noise and problems would multiply if linear translators were linked.

I believe that NZ not only had an AM repeater but also had a linear translator, so it would be interesting to hear their experiences.

One can only dream!