RFI from mains ethernet adaptors


Allan Isaacs
 

Here's a funny story for readers.
Ages ago I persuaded my next door neighbour to replace his mains ethernet adaptors and instead use a cable from his BT router through his loft to his TV located several rooms away.
I supplied a new cable and confidently expected severe interference to disappear.
The level however was unchanged so I lent him a portable receiver which he used to pinpoint the remaining noise from his cottage.
He said it was coming from a smart meter but nothing would persuade Southern Electric to fix this.
Today I was called to fix his Internet which had stopped working.
I fixed this and then noticed a black cable running from his BT router along the skirting board.. and it went to a mains ethernet adaptor with a green LED flashing merrily. He'd done away with the adaptor next to his TV but hadn't removed the adaptor at the router....
Anyway, I turned it off and now I'm RFI free.. at least from his house and 80m is clear as a bell...
Allan G3PIY


Max
 

On Sat, Sep 25, 2021 at 01:34 PM, Allan Isaacs wrote:
I fixed this and then noticed a black cable running from his BT router along the skirting board.. and it went to a mains ethernet adaptor with a green LED flashing merrily. He'd done away with the adaptor next to his TV but hadn't removed the adaptor at the router....
Anyway, I turned it off and now I'm RFI free.. at least from his house and 80m is clear as a bell...
On the subject of funny RFI stories, had new neighbour move in few weeks ago to house that had previously been practically unoccupied (second home) since we moved here about 7 years ago. Actually they are about 100 yards down road but I'm not in a very populated area. Was listening on 160m one Saturday morning. Hear horrible unstable RFI all over 160m band, SM PSU style hash. It's odd because it goes for a while, then a break, the starts, then a break. I am cursing because I convince myself in a panic that it's some piece of kit the new neighbours have brought in and plugged in! A bit later in the day it's gone. Relief all round.

Following Saturday morning I listen out for it again. Blow me if it is not there again. Set off outside with portable receiver, and swinging antenna back and forth it seems to be coming not from neighbour's direction but from my own house. Eventually track it down. It's our own washing machine. Suddenly realise that my other half does wash every Saturday morning. Machine is AEG (well John Lewis, but made by AEG). Makes RFI racket when motor is turning drum, hence the "stop-start". Disappointing but also a relief at the same time!

Max


Michael.2E0IHW
 

Max, you could volunteer to do the washing - 100%-RFI-free :-

On 26/09/2021 10:02, Max wrote:
Eventually track it down. It's our own washing machine.
...Makes RFI racket when motor is turning drum, hence the "stop-start". ..


Max
 

On Sun, Sep 26, 2021 at 11:35 AM, Michael.2E0IHW wrote:
Max, you could volunteer to do the washing - 100%-RFI-free :-
Don't worry, I am the modern man...... do my full share of the domestic tasks!

Max


Tom Crosbie G6PZZ
 

And generate your own wave energy…

 

Max, you could volunteer to do the washing - 100%-RFI-free :-

On 26/09/2021 10:02, Max wrote:

Eventually track it down. It's our own washing machine.

...Makes RFI racket when motor is turning drum, hence the "stop-start". ..


Kriss Kliegle KA1GJU
 

Max,
I cured mine with an FT-240-31 Ferrite Toroid and an improved AC line filter, all of which I installed inside the washer. My first SDR antenna (EFW) was overhead the washer by about 25'.
Mine had a similar, useless, small plastic AC line filter as the OP in the following page:
https://www.eham.net/article/12278

I don't remember the make and model of the filter, but was in a metal case just like the OP's. Between the toroid and the filter, it was gone! There's a little RFI coming from the control panel, but only within a foot of it.

73 Kriss KA1GJU

 


Allan Isaacs
 

Hi Kriss

This scan is from our Hotpoint washing machine in standby which plays musical notes on a portable radio. Not the usual mush.

The scan in green is the washing machine, 4MHz plus minus 1MHz.

Yellow 30 feet away.

Because the mains plug is behind the thing it will need an extension lead so I can turn it off from standby.

Allan G3PIY


From: main@SDR-Radio.groups.io [mailto:main@SDR-Radio.groups.io] On Behalf Of Kriss Kliegle KA1GJU
Sent: 26 September 2021 12:50
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] RFI from mains ethernet adaptors

 

Max,
I cured mine with an FT-240-31 Ferrite Toroid and an improved AC line filter, all of which I installed inside the washer. My first SDR antenna (EFW) was overhead the washer by about 25'.
Mine had a similar, useless, small plastic AC line filter as the OP in the following page:
https://www.eham.net/article/12278

I don't remember the make and model of the filter, but was in a metal case just like the OP's. Between the toroid and the filter, it was gone! There's a little RFI coming from the control panel, but only within a foot of it.

73 Kriss KA1GJU

 


Brent Seres/ VE3CUS
 

FWIW,  here in Canada, I have opened up switching supplies and found spots on the circuit board where components were missing.  I've long suspected that these may have been filter components which were included in a device when submitted for testing and approval prior to sale, and left out for cost savings once approved  No proof...just suspicion..

73
Brent
VE3CUS 





Mike N7ZEF
 

Muntz Radio...They were infamous for removing parts that didn't seem to make a difference in operation...Their logo was Napoleon...

73
 Mike - N7ZEF

On Sun, 26 Sep 2021 11:43:09 -0600, Brent Seres/ VE3CUS <brentseres1@...> wrote:

FWIW,  here in Canada, I have opened up switching supplies and found spots on the circuit board where components were missing.  I've long suspected that these may have been filter components which were included in a device when submitted for testing and approval prior to sale, and left out for cost savings once approved  No proof...just suspicion..

73
Brent
VE3CUS 







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jdow
 

Mad Man Muntz

Ah the memories! One of his TVs was gutted to help build my first "junk box".

{^_^}

On 20211005 20:04:47, Mike Reed wrote:
Muntz Radio...They were infamous for removing parts that didn't seem to make a difference in operation...Their logo was Napoleon...

73
 Mike - N7ZEF

On Sun, 26 Sep 2021 11:43:09 -0600, Brent Seres/ VE3CUS <brentseres1@...> wrote:

FWIW,  here in Canada, I have opened up switching supplies and found spots on the circuit board where components were missing.  I've long suspected that these may have been filter components which were included in a device when submitted for testing and approval prior to sale, and left out for cost savings once approved  No proof...just suspicion..

73
Brent
VE3CUS 







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