NBN interference

[VK2VRC]

I have an aerial lead in , from the telegraph pole on the street to the box on the house , it is an old copper lead fitted in the very early 70's ,when I first moved here .

I asked the technician when they were installing the NBN ,if he was going to replace it, and he said it was still ok .I had a feeling he was on commission for how many installs he did per day ,and was not really interested.
I have broadband interference , since this problem popped up about a month ago ,59+ on 40m and 80m , but my dipole on these bands doesn't seem to cause the same increase in the noise around my transmitted signal.But on 20m with the Yagi,it only takes a couple of watts to cause the problem, which sounds a bit like the woodpecker ,but at a higher and faster rate.
have been wondering if it was caused by water ingress ,either from a flooded pit, or from one of those black connectors on the telegraph poles.As it is strange that I have never previously had any noise, and then during all that very heavy days of rain, the noise suddenly appeared.I was listening the moment that it started,I initially thought I had a problem with the software on my SDR.But changing radios,quickly showed it wasn't radio induced.

I have to call my ISP anyway, because I now have a problem with my home phone, which now runs through the NBN ,I call some phone numbers here in Sydney ,and get a message that " my call can't be completed with the long distance company that I have selected .Please dial your call within access code" whatever that is supposed to means it is a local call within Sydney. It is a reason to get a technician involved, and hopefully the 2 problems are related .


In my case it took much persistence.

You need to accept that in the first instances you will need to deal with your ISP as they are the first port of call.  This will lead to much frustration.

In the end I was lucky that it got escalated and once the NBN tech's got involved there was progress but no fix.

One thing that did make a small difference is that the lead-in was recabled with a tight twist Cat6 type cable from DPU to NCD.  We have a aerial lead-in which acts like a big old antenna, the Cat6 reduced some of that.

I was told by the NBN network engineer who came to visit that the VDSL modulates between 10 and 140 MHz.  When RF enters the system in that range the NCD senses the change in conditions and turns up the power to overcome the 'interference'.  For me this resulted in broad-band interference. 

I wonder if this was caused by water ingress and the cable (either underground or in infrastructure) that is causing some kind of earth load and the NCD is trying to overcome it by turning up its output?

Your ISP should be able to detect line issues such as this with their tests.

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I have had FTTC for about 12 months or so ,without any problems, then last month, during the big rain event we had, suddenly I have S9 noise on 40m and 80m and S8 noise on 20M , but when I transmit on 20M I get a noise signal that appears to attach itself to my transmit frequency . I would understand if it appeared when they installed the NBN,but this is nearly a year later.



This happens as soon as I key up and the noise is very loud.
What should I tell NBN Co when I call them,I am sure they will be very helpful if I say that I have interference on my Amateur radio equipment ?

Regards

Wayne 
VK2VRC

Hello Wayne,
check the AM radio band for interference, they are obliged to fix any interference to AM broadcast and it is something they will understand about when the fault is reported.I had problems with fixed wireless early on as it killed 160 / 80 /40 here and also killed AM broadcast....  they did not give two hoots about HAM but they understood they had to fix AM broadcast   
My roof top unit was replaced and problem had not appeared again.
Regards,
Peter, vk5pj

Hi Peter

Checking the broadcast bands is one of the first things I did , as I know that ACMA are not interested in helping Amateurs , but if I had interference on the broadcast bands ,then as a member of the public ,they would be compelled to look into it . But the broadcast stations are so strong here ,the signal would need to be extremely strong to cause any problems.

Wayne 
VK2VRC