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[snadge]

I saw a video on YouTube of a guy solving drop outs by putting ferrite cores on some of his mains appliances to cancel/lower RFI - is this correct?

[Weaver]

I have done this on DC cables, not on mains. It’s superstition on my part. Theoretically it could block interference getting up the dc cables into the kit but whether or not it actually does snyth8ng depends on whether there is any noise in the first place plus a whole lot of stuff about the behaviour of the circuitry inside the devices in question. I haven’t even ever done proper testing with-vs-without either, which would be extremely difficult anyway and even if there are any resulting differences, the differences would be small and that would make it difficult to measure them.

[JGO]

Here we go again !

Ferrite cores can be very effective IF the cause and its mode of propagation are known.( within limits)

If not you are depending on luck.

[j0hn]

Buying a random ferrite core and slapping it on your DSL cable is a waste of time, waste of money.

Here we go again !

Ferrite cores can be very effective IF the cause and its mode of propagation are known.( within limits)

If not you are depending on luck.

I was just about to link to a couple of your posts.

A forum search of "ferrite core" provides a good read.

https://forum.kitz.co.uk/index.php/topic,13380.msg252015.html#msg252015
https://forum.kitz.co.uk/index.php/topic,21529.msg372496.html#msg372496

The next link is probably the only example I've seen where it's been done right
They had a specific purpose, trying to filter RF on a specific frequency. They also knew what they were doing.

https://forum.kitz.co.uk/index.php/topic,20136.msg354475.html#msg354475

I have a box with around a dozen different types of ferrite core, which came from a company liquidation (around 20 of each type, some 200+ in total).
Not 1 of them had any noticeable effect on the xDSL circuit.
This box is in the attic gathering dust.

The only ferrite core in use here is the couple that came with some expensive audio equipment.

[snadge]

It was in reference to mains power noise... such as washing machines, dryers, power tools etc that may be causing a really bad noise increase, the advice was to NEVER put one on your DSL cable (which seems sensible enough) as it will increase loss/attenuation, but if you have something that's doling out lots of noise, then apparently putting Ferrite Cores on the device in question's mains cable is helpfull..?!

[ejs]

Was the video basically an advertisement from someone selling the things?

[snadge]

Was the video basically an advertisement from someone selling the things?

no it was just a video on how to better your long/noisy dsl line

[ejs]

I almost want to watch the video, just to see how horrendous it is.

[snadge]

it was bad lol... a 'red-neck' with colourful language, you could tell he knew very little and some (actually a lot) of his instruction was poor, however it was the first time I heard of using 'Ferrite Cores' so thought I would ask the experts

[JGO]

"Ferrite" is the magnetic core material and just for rejecting RFI on power lines  you can use it three ways.

Firstly a single hole core ("bead") on each conductor will attenuate RFI pickup. This has the advantage you can slide the cores along the conductors  to maximise attenuation.

OR a 2 hole (balun) is designed to attenuate common mode interference on a balanced feeder so it will work to clean up power leads the same way.


OR a big (transformer core)  ferrite will attenuate RFI in a twin power line wrapperd round it a number of times,

[vultura]

I have to confess to adding ferrite beads to various plug-in PSUs in my house to try and resolve the load speed issue I feel I have.

Whether they make a difference in reality I don't know, but I assume (perhaps incorrectly) that they won't make things worse.

[ejs]

I've got a couple of old AC/DC adapters that were made with ferrites on their DC cables. Or at least that's what I assume is in those cylinders on the leads.

[vultura]

I've got a couple of old AC/DC adapters that were made with ferrites on their DC cables. Or at least that's what I assume is in those cylinders on the leads.

Yes they will be.

Used to be quite common on VGA cables too.

[banger]

My Fuji camera has ferrite cylinders on both power and data cables.

[vultura]

So, if adding them to DC cables on PSUs for example are they likely to have a detrimental effect?