Telstra complains of QRM!

[VK3PY]

An article of interest from today's Age newspaper with which we can all identify:

http://www.theage.com.au/it-pro/busines ... 0h252.html

Chas
VK3PY

[VK2XSO]

I'm one of the people who sometimes has to chase down these devices.
Mobile phone repeaters cause a lot of problems. Some of them are well installed and do not cause any problems.
Having said that, the noise they generate can be seen by the network and if we know anything about shannon's law, its that noise reduces the usable bandwidth.
Telstra's gods on olympus who monitor the network and it's performance can see where and how many of these repeaters are out there. (A lot).

Telstra isn't complaining about what is outside of their bands, they have some filters which could muffle the sound of an atomic bomb dropped in the next suburb.
What they're complaining about is what is inside of their band, and fair enough they pay a little bit of money in licence fees for it.

Mobile repeaters are the main source of interference.
One of the guys who's full time job it is to hunt down interference was showing me some of the places they turn up.
A recent one he had spent months trying to find turned up in the back of a ute. The guy had been driving all over NSW with it causing massive problems.

Masthead amplifiers are another. I was at agquip and I was called back to the site because it had "problems" and the called in the regular interference chaser to help.
Two sources of interference, the first was a mobile repeater, but as we got close, it suddenly disappeared, The two guys with yagis must have been a give away.
The second source of interference was a masthead amp that went faulty at the jaycar stand.

Now with the move into 700MHz and 2600MHz, well you can imagine there might be a few cobwebs left in the corners of the bands.
Especially down at -130dBm.

[VK2FABS]

Does this "mobile repeater" issue relate to mobile boosters? I note ACMA's site talked about them with differentiation. And what purpose does a guy have in having one of these sitting in the back of his car?

[VK3BQ]

You can follow the grey nomad migration looking at cheap mast head amplifier noise on 900mhz as it sweeps accross the tundra as the old people move towards the heat each winter!!

Telstra have it easy. They are not inside the US ISM band.

The recent grief seems to come from 902mhz hopper weather stations.

[VK4KL]

I am about to install a wireless repeater to allow Internet access in my shed hope these don't cause problems

Adrian

[VK3ZAZ]

An article of interest from today's Age newspaper with which we can all identify:

http://www.theage.com.au/it-pro/busines ... 0h252.html

Chas
VK3PY

I was unaware they didn't already have the power to act...
They come down on us with 1982-1989 circa FM transmitters emitting 9th harmonic radiation deigned in a day when no one even thought of the 3G and 4G bands.
Total unrealistic expectations of 30 YO equipment and the noise floor values it is seeking for its base stations sited on ór adjacent to TV and radio sites (which it built back in the 70's) running thousands of KW of RF in the FM and UHF bands.
You cant filter out what radiates from a cabinet..
Then we have smart meters designed in India 10 years ago with software defined illegal power levels running external dipoles to reach base stations pinging all over the top end of 900mhz.
All this in the name of mobile phones which have evolved into mobile computers to browse the internet 24/7....
And the cost of moving all the TV stations below CH 50 is mind blowing along with NBN expenditure on sites.
BiLLION$ of TAXPAYER$ DOLLAR$
Good Luck Telstra you are chasing shadows...

As for grey ghosters running phone repeaters along the highways and byways, who thought up that bit of nonsense.
Those people wouldn't even know how to retune their tv set let alone run technology like that..
Ah well ACMA can always run Winebago raids at the borders like they did decades ago chasing CB truckers.

[VK3BQ]

Lots of problems. And a big fine. Should they come looking. http://www.acma.gov.au/~/media/Complian ... %20pdf.pdf

[VK4TI]

I am about to install a wireless repeater to allow Internet access in my shed hope these don't cause problems

Adrian

I hope its a 5 gig unit

[VK3ZAZ]

Lots of problems. And a big fine. Should they come looking. http://www.acma.gov.au/~/media/Complian ... %20pdf.pdf

YEAH|
How about they chase the power providers trying to install outside antenna to Smartmeters exceeding the EIRP on the 900 MHz class band of 1 watt E.I.R.P.
Some sdr meters out in bush have been cranked up (5 watts) to reach base stations kilometres away.
ACMA doesn't want to know.

[VK4WDM]

"Some sdr meters out in bush have been cranked up (5 watts)"

What are the EMR implications of that? How far away from human heads are these antennas?

73

Wayne VK4WDM

[VK3ZAZ]

"Some sdr meters out in bush have been cranked up (5 watts)"

What are the EMR implications of that? How far away from human heads are these antennas?

73

Wayne VK4WDM

1.2 metres
Mine sets off my Rad Monitor
beeper went off when they put it in
Electrical inspector just laughed and walked away said not his problem
ACMA said it WILL comply, would not come and look
So I have big yellow sign on it warning EMR
have it on good authority from friend in SEC that the sdr txers have nevr been set up
come out of container at full power

as far as emr implications who is kidding who
even hams mainly only do calculations
hm have a rad monitor or even have borrowed one and done a check around their houses?

[VK4WDM]

have a rad monitor or even have borrowed one and done a check around their houses

A bit off topic but there has been a thread on whether hams should have/use a rad monitor. Those who work in the field thought that the the cheaper models (?less than about $500) are a waste of time and that only an industry approved one would give readings that meant anything. Probably too expensive for individual hams to buy but my suggestion was that clubs could look at purchasing one for their members to use.

73

Wayne VK4WDM

[VK2XSO]

Lots of problems. And a big fine. Should they come looking. http://www.acma.gov.au/~/media/Complian ... %20pdf.pdf

It's the usual ACMA thing. They have a big stick, they just can't lift it to swing it because it's too heavy. It makes it very difficult to swat a gnat.

It's not the ACMA who chases the interference, it is Telstra.
When they find a source of interference, they just talk to the source.
Most people are unaware and are more than happy to comply by turning off their equipment. For the price of a new masthead amp I know they've been considering just paying to have them replaced.
The problem is fixed and it doesn't come back and it's good PR.

In the case of repeaters most people have forked out a reasonable sum of money. So not only do they lose their phone coverage they've wasted money on something.
The temptation is there to just turn it back on. Most people don't.
There is also a small group of people who use similar words, "Get the f. off my dirt farm!"
The interference techs give them a pre-fab printed warning with the blurb from the ACMA and it ends up on the ground.
The interference gets reported to the ACMA, but I've not heard them acting upon any of it. They probably do, but I've not heard of it.
Most people do the right thing.

[VK3BQ]

And Optus. It's my day job. And they do act.

[VK2AAH]

I had a moron from Optus call me the other day... made accusations of interference based on the ACMA database list of assignments rather than using his test equipment. He had no understanding of intermod... I told him to provide me with real evidence before I committed tax payer money to travel 800km. I haven't heard back. My concern is that the people doing this work for the carriers have little experience or education to undertake this work. There was a time when ACMA had people like Gilbert Hughes who were logical and thorough... not many of those left in the industry.

Cheers


Richard
VK2AAH

[VK3XL]

logical and thorough... not many of those left in the industry.

Not many left in any industry is my guess. I certainly dont come across many in Higher Ed.