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Author Topic: 20m and My Washing Machine  (Read 749 times)

KJ4DMO

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20m and My Washing Machine
« on: December 25, 2021, 03:43:26 AM »

Howdy & Merry Christmas! Let’s get to it…
1) new to HF
2) new IC-7300
3) fanned dipole in attic (all I can do at the moment)

I think I have a mischievous RFI poltergeist, that seems to appear mostly on 20m.

Weird things happen when I transmit in that band (maybe other bands too):

1) I can hear myself coming through a set of headphones on my bench that are plugged into a small headphone amp but the volume is turned all the way down.
2) a “smart” WiFi-enabled outlet strip in my shack turns on/off random outlets.
3) the somewhat new washing machine (they don’t make ‘EM like they used to!) gets confused…stops running, flashes an error code, needs to be unplugged and plugged back in to get working again. Only seems to do this when I’m in the next room transmitting. I know this because my wife regularly interrupts my QSO’s asking for help with the device.

Watched this presentation and learned a lot: https://youtu.be/LSL1h6MJbaI

Do y’all think some well-placed ferrite on both my radio power cabling and the washing machine power cord will exorcise these demons, or is my haunting something indicative of a larger problem?
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K1FBI

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Re: 20m and My Washing Machine
« Reply #1 on: December 25, 2021, 04:40:15 AM »

Howdy & Merry Christmas! Let’s get to it…
1) new to HF
2) new IC-7300
3) fanned dipole in attic (all I can do at the moment)

I think I have a mischievous RFI poltergeist, that seems to appear mostly on 20m.

Weird things happen when I transmit in that band (maybe other bands too):

1) I can hear myself coming through a set of headphones on my bench that are plugged into a small headphone amp but the volume is turned all the way down.
2) a “smart” WiFi-enabled outlet strip in my shack turns on/off random outlets.
3) the somewhat new washing machine (they don’t make ‘EM like they used to!) gets confused…stops running, flashes an error code, needs to be unplugged and plugged back in to get working again. Only seems to do this when I’m in the next room transmitting. I know this because my wife regularly interrupts my QSO’s asking for help with the device.

Watched this presentation and learned a lot: https://youtu.be/LSL1h6MJbaI

Do y’all think some well-placed ferrite on both my radio power cabling and the washing machine power cord will exorcise these demons, or is my haunting something indicative of a larger problem?

I had the same exact problem with my new washing machine. It was the safety switch for the lid. I disconnected it. (This is where all the safety officers chime in).

I tried what you are thinking with minimum results.

All my problems were eventually quelled with 2 MFJ-915 line isolators, one at each end of my coax. I used a 3’ jumper coax before the antenna.

They are multiple ferrites used to create an RF choke.
Yes, you can make one yourself but it wouldn’t be cost effective. These are inexpensive and one of the few good products MFJ still makes.

And YES the safety switch on the washing machine lid is reconnected…
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W9IQ

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Re: 20m and My Washing Machine
« Reply #2 on: December 25, 2021, 05:12:53 AM »

An attic antenna can cause all sorts of havoc with modern household electronics. The RF easily couples into household wiring, HVAC ductwork and CATV coax shields. The results can make you feel like you are playing an RF version of wack-a-mole.

The good news is that with diligence and patience, you can gradually bring the household electronics back to normal operation. In most cases, applying ferrite chokes will be sufficient but occassionally additional measures are needed. The ferrite you will use is type 31 (also called mix 31). Do not substitute any old ferrite - the mix is the key to making an effective RF choke. Perhaps the only exception is if you happen to have some type 43 ferrite in your parts box already. This isn't as effective as type 31 but it is the next best.

Start with a proper common mode choke at the center of your fan dipole. This prevents RF from traveling on the outside of your coax braid. This may not solve all of the issues but there is no meaningful downside either. Recheck for interference after installation. This is similar to the recommendation from K1FBI.

Next is to apply ferrite to cords and cables going into and out of affected devices. It is generally more effective if you can put a few turns of the cord through the ferrite. So purchase ferrite sizes with this in mind.

Here are a few sizes that would be good for your project. These are all Fair-Rite part numbers for type 31 material:

2631814002 for the electric dryer cord (you will need to remove the cord to wind it). A toroid with a 3 inch center hole. $26.27

2631803802 for most 120 volt cords and for the dipole common mode choke. A toroid with a 1.4 inch center hole. $6.04

0431167281 for most audio/network/USB cables. A split/snap-on core with a 0.4 inch center hole. $2.97

The prices are from Newark. Last time I checked, they had the best flat rate shipping price but Mouser, Arrow and Digikey are other options.

Good luck with the project and Merry Christmas!

- Glenn W9IQ
« Last Edit: December 25, 2021, 05:22:26 AM by W9IQ »
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- Glenn W9IQ

God runs electromagnetics on Monday, Wednesday and Friday by the wave theory and the devil runs it on Tuesday, Thursday and Saturday by the Quantum theory.

W0RW

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Re: 20m and My Washing Machine
« Reply #3 on: December 25, 2021, 08:28:15 AM »

   My XYL's new Speed Queen Washing machine has gobs of digital noise coming out of it, even when it is off !  I contacted the factory and told them the "Off" switch doesn't turn the machine OFF !, They said I need to buy a 15A line filter, that has no specs.
   So i built a RFI filter for my washing machine using 2 big Sprague  10JX34, 10A, feed coaxial feed filters.
   I have a 6A filter,  Rockwell Automation 2090 for bigger power supplies that needed it.
   I bought a dozen Schaffner FN2080-3-06 (3A) Power Line Filters (From eBay) for my low current items and put them on all the worst radiators around the house.
   I don't mind noisy things that I know about that can switch off or unplug, I have them tagged.
Paul   w0rw
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KF4HR

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Re: 20m and My Washing Machine
« Reply #4 on: December 25, 2021, 10:45:28 AM »

In many homes house wiring distribution is laid throughout the attic.  An attic antenna can easily induce RF into that house wiring and the RF can negative affect many things in the home.  If possible, go with an antenna outside.

KF4HR
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KH6AQ

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Re: 20m and My Washing Machine
« Reply #5 on: December 25, 2021, 12:23:39 PM »

What I would do...
1) I can hear myself coming through a set of headphones on my bench that are plugged into a small headphone amp but the volume is turned all the way down.

Shut the audio amp off.


2) a “smart” WiFi-enabled outlet strip in my shack turns on/off random outlets.

Disconnect the outlet strip and use a dumb one.


3) the somewhat new washing machine (they don’t make ‘EM like they used to!) gets confused…stops running, flashes an error code, needs to be unplugged and plugged back in to get working again. Only seems to do this when I’m in the next room transmitting. I know this because my wife regularly interrupts my QSO’s asking for help with the device.

Wrap the power cord thru two stacked FT240-31 or FT240-43 cores as many turns as will fit. This is the no risk filter; it will not affect the washing machine. An external filter incorporating differential-mode chokes may upset the switching power supply in the washing machine. The MFJ-1164B AC line RFI filter is such a device.

https://www.dxengineering.com/parts/mfj-1164b/documentation
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AC2EU

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Re: 20m and My Washing Machine
« Reply #6 on: December 25, 2021, 02:56:03 PM »

I wonder if anyone has tried putting a .047 to .1 uf safety cap across the line?

My washing machine transmits on 12 meters, but no big deal. It would be great if there was a simple fix for it.
I tried a snap-on type EMI device, but it didn't help much.

KJ4DMO

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Re: 20m and My Washing Machine
« Reply #7 on: December 25, 2021, 03:17:37 PM »


I had the same exact problem with my new washing machine. It was the safety switch for the lid. I disconnected it. (This is where all the safety officers chime in).

I tried what you are thinking with minimum results.

All my problems were eventually quelled with 2 MFJ-915 line isolators, one at each end of my coax. I used a 3’ jumper coax before the antenna.

They are multiple ferrites used to create an RF choke.
Yes, you can make one yourself but it wouldn’t be cost effective. These are inexpensive and one of the few good products MFJ still makes.

And YES the safety switch on the washing machine lid is reconnected…

K1FBI,

I have a hollow core choke I made by wrapping 21 feet of coax around a piece of PVC. It is located right at the base of the antenna. Would the MFJ-915’s replace it?

Thanks!
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KC6RWI

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Re: 20m and My Washing Machine
« Reply #8 on: December 25, 2021, 03:20:49 PM »

My whirlpool washer does the same thing, an error light flashing, when it has sensed rf, the same kind of light you get if you open the lid while work is being done. I would guess that the switch is open when the lid is closed, making the leads an antenna, but that is pure speculation.
I also have astron power supply, 35 amp and when I use certain tools on the same electrical outlet branch I will get a low growl from the ps, seems to come from the transformer from the sound of it.
I don't think its any concern??
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W9IQ

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Re: 20m and My Washing Machine
« Reply #9 on: December 25, 2021, 04:18:23 PM »

I have a hollow core choke I made by wrapping 21 feet of coax around a piece of PVC. It is located right at the base of the antenna. Would the MFJ-915’s replace it?

13 turns of coax through the 2631803802 core will give far superior choking performance.

- Glenn W9IQ
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- Glenn W9IQ

God runs electromagnetics on Monday, Wednesday and Friday by the wave theory and the devil runs it on Tuesday, Thursday and Saturday by the Quantum theory.

K1FBI

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Re: 20m and My Washing Machine
« Reply #10 on: December 25, 2021, 04:25:44 PM »


I had the same exact problem with my new washing machine. It was the safety switch for the lid. I disconnected it. (This is where all the safety officers chime in).

I tried what you are thinking with minimum results.

All my problems were eventually quelled with 2 MFJ-915 line isolators, one at each end of my coax. I used a 3’ jumper coax before the antenna.

They are multiple ferrites used to create an RF choke.
Yes, you can make one yourself but it wouldn’t be cost effective. These are inexpensive and one of the few good products MFJ still makes.

And YES the safety switch on the washing machine lid is reconnected…

K1FBI,

I have a hollow core choke I made by wrapping 21 feet of coax around a piece of PVC. It is located right at the base of the antenna. Would the MFJ-915’s replace it?

Thanks!
Interesting, that is what I tried first with marginal results.
Yes, but first try running a short jumper between the choke you made and the antenna.  You don't want your jumper to be a resonant length on any frequency you transmit on.
If it doesn't help try the MFJ-915s, they worked for me.
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K1FBI

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Re: 20m and My Washing Machine
« Reply #11 on: December 25, 2021, 04:32:18 PM »

I have a hollow core choke I made by wrapping 21 feet of coax around a piece of PVC. It is located right at the base of the antenna. Would the MFJ-915’s replace it?

13 turns of coax through the 2631803802 core will give far superior choking performance.

- Glenn W9IQ

I think Glenn is leading you to experiment and have a little fun learning. Yes you certainly can wrap your own as he suggests. You can even put it in a project box with coax connectors on each end.  Lot's of articles on the internet.
I made one myself for the car and it did indeed work.
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KI5FJ

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Re: 20m and My Washing Machine
« Reply #12 on: December 26, 2021, 06:20:37 AM »

I recommend installing a Tripp-Lite Iso-Bar Ultra in the power cord of the washer and rig.
I have used these in calibration laboratories for years. The RF choking is usually enough to tame
the RFI beast. However, your Attic antenna's radiation may be to much for the consumer electronics to ignore.
I suggest you re-validate your RF Safety computations. A "Rule of Thumb" if consumer electronics is affected, the level of RF is probably in excess of the safe limits. Be Well & 73, Joe O, K I 5 F J, NNNN
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N5PNZ

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Re: 20m and My Washing Machine
« Reply #13 on: December 26, 2021, 07:40:16 AM »

Our not so old Whirlpool washer talks to my receivers on 10 and 12 meters. And it does it across the entire bands.  I can tell it is operating on 15 meters but the signal is very low.  On 10 it wipes out the band.  To my knowledge my transmissions do not effect the washer.
Those lid switches are prone to failure on their own.
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K1VMT

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Re: 20m and My Washing Machine
« Reply #14 on: December 26, 2021, 10:13:03 AM »

I had a Cabrio fancy machine digital... and got rid of it for a Manual type Speed Queen
It cleaned RFI from washer.. but it's not the only culprit in the house.. hi hi

Joe
K1VMT
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