Re: Feed Line Noise

David Cutter

I'm not fully up to date but the last I heard was that the band of frequencies used for data distribution has the FACILITY  to notch out the amateur bands.  I recently heard that this is not always done and is done by the engineer in the street at the box, but is not part of their regular training so, might not/probably not done.  I don't have it to hand but there was an excellent article in RADCOM recently about this.

David G3UNA


From: [] On Behalf Of Tom Crosbie G6PZZ
Sent: 07 April 2019 14:04
Subject: Re: [CrossCountryWireless] Feed Line Noise



Could you please expand on “notching”. I have Previously built notch filters for 2m/70cms to insert in my neighbours TV downlead, so I’m familiar with the basics, just not how it applies to VDSL/ADSL.

Is this some magic device that would fit to the telephone line?

What are the magic words to say to an engineer to make a start on this process?

Kindest regards



From: <> On Behalf Of David Cutter via Groups.Io
Sent: 06 April 2019 16:04
Subject: Re: [CrossCountryWireless] Feed Line Noise




That's very interesting, as is the LZ1AQ data.  Does your experience then tell us that the VDSL signals are in fact coupling directly to the antenna and it is then irrelevant what else is happening? 


Your only escape is to place the antenna remotely, ie long distance from VDSL sources. 


So much for notching which is only done on a site by site basis and only if you know the engineer to ask, etc.


David G3UNA


From: [] On Behalf Of leslie norton
Sent: 06 April 2019 15:47
Subject: Re: [CrossCountryWireless] Feed Line Noise


I don't want to put a spanner in the works but it depends on what the noise is, i'll give you an example, I had a Wellbrook loop and could not null out the noise (mine is caused by VDSL) I decided to go for the CCW active loop in the hope the filtering might be better. It isn't, I still have the same issues so in a way ive wasted money. My CCW is outside and above the lines that cause issues although ive tried in in loads of positions. The dropper cables are attached to all the houses and i live in a square so 360 degrees, I have the CCW mounted on a Yeasu rotator. I have now come to terms with not operating (apart from digital) on affected bands.
VDSL is particularly troublesome to amateur radio.
I have tried all sorts of filters and nothing works for VDSL.



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