18-01-2020, 07:15 PM
Eventually the guru's from NBN turned up with a bunch of VDSL test gear - specan like equipment.
The interference was the signal between the NCD (in the house) and the DPU (in the street). As we have an aerial lead in and VDSL operates in a a band of 10 to 150 MHz (or thereabouts, I can't remember the exact numbers) the lead in is in effect a very large antenna.
I had already replaced the Telecom Australia installed 2 pair with Cat 5, NBN replaced the 40+ year old 1 pair IBC lead in with a screen bearer Cat 5 equivalent. This reduced the RFI a fair bit but it is still there.
In the image you can see where I triggered the NCD/DPU to start interfering (2 or 3 watts at 14 MHz using FT8 triggers it each and every time) - the interference continues until the NCD/DPU is powered down and restarts. By the by, the NCD powers the DPU so not only are you paying for the service you are also paying to power it too.
The NBN engineer believes that as the VDSL is broadband and the RF from my station is in it's bandwidth then the NCD sees it as interference and turns the wick up and that's where the interference appears in the waterfall. Although he could see the interference in his equipment and in my equipment and saw that powering down the NCD and/or DPU stopped the interference there was nothing else they could do.
ACMA weren't interested as they can only refer it to NBN and as I had already had contact with NBN they couldn't help.
I have tried numerous other things like rerouting antenna cables, moving antennas, different antennas, turning the xmitter power right down (and right up), etc.
So after many tens of hours of frustrating phone calls, live chats, days off work, running cables and much frustration I've cut my losses. HF voice simply isn't viable here due to too much QRM from railways, high voltage transmission lines and many other spot sources, so digital modes (FT8 mostly) allowed me to get back on air, now that is too difficult and frustrating which has killed any fun.
The upside is I have much more room on my workbench now.
Cheers.
The interference was the signal between the NCD (in the house) and the DPU (in the street). As we have an aerial lead in and VDSL operates in a a band of 10 to 150 MHz (or thereabouts, I can't remember the exact numbers) the lead in is in effect a very large antenna.
I had already replaced the Telecom Australia installed 2 pair with Cat 5, NBN replaced the 40+ year old 1 pair IBC lead in with a screen bearer Cat 5 equivalent. This reduced the RFI a fair bit but it is still there.
In the image you can see where I triggered the NCD/DPU to start interfering (2 or 3 watts at 14 MHz using FT8 triggers it each and every time) - the interference continues until the NCD/DPU is powered down and restarts. By the by, the NCD powers the DPU so not only are you paying for the service you are also paying to power it too.
The NBN engineer believes that as the VDSL is broadband and the RF from my station is in it's bandwidth then the NCD sees it as interference and turns the wick up and that's where the interference appears in the waterfall. Although he could see the interference in his equipment and in my equipment and saw that powering down the NCD and/or DPU stopped the interference there was nothing else they could do.
ACMA weren't interested as they can only refer it to NBN and as I had already had contact with NBN they couldn't help.
I have tried numerous other things like rerouting antenna cables, moving antennas, different antennas, turning the xmitter power right down (and right up), etc.
So after many tens of hours of frustrating phone calls, live chats, days off work, running cables and much frustration I've cut my losses. HF voice simply isn't viable here due to too much QRM from railways, high voltage transmission lines and many other spot sources, so digital modes (FT8 mostly) allowed me to get back on air, now that is too difficult and frustrating which has killed any fun.
The upside is I have much more room on my workbench now.
Cheers.
Colin
Barossa Valley, SAP. PF95ln
(aka VK5CSW)
Barossa Valley, SAP. PF95ln
(aka VK5CSW)