[RFI] ADSL2 RFI

[Jim Brown]

On 2/7/2020 1:57 PM, HP wrote:
> Are there any ADSL2 gurus on this reflector

Hank,

I have no experience with ADSL, but lots with RFI, especially 
suppression of common mode coupling at MF and HF. The same chokes that 
are effective for TX and RX antennas are also effective on data lines.

Something else that can help is to replace as much as possible of the 
length of Telco's lines that are within the near field of your antennas 
with a good grade of UTP CAT5/6/7. Belden makes a number of these cables 
with pairs that are individually molded to prevent deformation of the 
twist when the cable is bent.

Many years ago, Bud, W2RU, had to deal with a problem like this, and we 
corresponded extensively about it at that time. Also many years ago, 
W8JI encountered similar issues, called the DSL provider to fix it, and 
got them to install a new interface which, I think, took care of the 
problem. You might want to touch base with either or both of them.

Also, take a look at http://k9yc.com/KillingReceiveNoise.pdf and 
http://k9yc.com/KillingRXNoiseVisalia.pdf about radiation of "backhaul" 
data on both DSL and CATV lines, and about Plasma TVs. It's page 15 of 
the text link, slides 181 - 197 in the other link.

Note that I also strongly recommend using as little wired ethernet as 
possible, both because of the birdies that are present, but also because 
it can act as antennas to receive and transmit RFI. I've used only WiFi 
for at least 15 years. With thoughtful placement of a good quality WiFi 
router, the system works just fine for every application I need, 
including streaming hi res video.

73, Jim K9YC