Ferrite, chokes, and RFI
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- เผยแพร่เมื่อ 4 มี.ค. 2017
- An introduction to ferrite and chokes, and how to use them to stop RFI (radio frequency interference).
Buy ferrite on my website: www.kf7p.com/KF7P/Ferrite_chok...
More how-to and tech resources on my tech page: www.kf7p.com/KF7P/Tech_Resourc...
ARRL RFI book: www.kf7p.com/KF7P/Publication...
More info from the ARRL: www.arrl.org/radio-frequency-i...
W1HIS Choke info: www.yccc.org/Articles/W1HIS/Co...
K9YC RFI ham: audiosystemsgroup.com/RFI-Ham.pdf - วิทยาศาสตร์และเทคโนโลยี
“My child was misbehaving, so I fixed that problem by just wrapping him around some ferrite.”
Your sewing machine started by itself. Time to put down the ferrite and call a priest.
Ha! Ha! Ha!
The power of Christ compels you!!!
My station turns on the TV downstairs and then programmes in all manner of settings I don't know how to get out of. It's midnight and the house is completely dark and all of a sudden I hear reruns of The X Files blaring at full volume downstairs, on a channel I didn't know I even got. Priest, is right.
Or you could have done a little more research and realized he has a faulty switch that has an open or semi open connection and just replace the switch by soldering a few wires lol
This would be a great whole other video, I would love to see.
Very helpful. I needed to see real-world examples of fixing these problems. Thanks
I googled "How do I turn all of my long cables into 6" cables" and found this video... :) Seriously though, I will be buying a few cores from you...
HAHAHA I was thinking the same thing. 12' cable = now 7.34' (and it weighs 10 lbs now BTW)
😂😂😂
Your family is very tolerant and patient
This guy taking ferrite seriously
**wraps your comment around some ferrite cores**
Rap ear around core so no interference from wife...
Never knew, you could get addicted to ferrite.
@@coffee24seven That is is funny right there!
great job. No long winded introduction and real life solutions. Thank you.
Legend has it that he was so fed up of his wife’s interference that bound her in ferrite 😂 now she’s very quiet 😂
Buried her in a ferrite sarcophagus, last time I heard.
And dropped her in the river?
IF
0NLY that worked
:DDD
Thank you for the helpful video. Is there any good resource on how to reduce noise while trying to monitor VLF and LF bands using an active mini-whip antenna??
I have a military headset with a civilian high impedance mic and a adapter cord to a 1\8 inch jack for the mic and headset. It is used on my computer and I hear spanish music whenever the mic is plugged in. When the computer is turned off it is silent. One other thing if I hold the mic jack it is silent. Would a ferrite core help somewhere?
I will have to follow this up. However, my problem is with RFI egress from HDMI and cat 6 cables. This is causing grief to a radio mic receiver in a fixed auditorium PA. The receiver measure -20 dB broad spectrum RFI across every channel and proximity testing confirms RFI is generated by these cables. RFI only exists while video signal is present in the HDMI over cat 6 cabling. It is difficult to reduce proximity as the source device is in the AV desk. I am not sure if ferrite is the answer here as the square wave signal pulse is creating a GHz transmission aerial effect (egress) while ferrite seems to be effective at attenuating ingress. Perhaps I need to run the cables in grounded copper tubing. I'd appreciate advice as to which approach to pursue.
quick question, if i loop the positive and negative supply to the back up camera in may car , around some Ferrite will it reduce the engine RF interference that i see in the backup video? or will i need a capacitive solution?
Sewing machine running by itself? Crazy yet interesting. Two common ones at home for me is dimmer switches to AM radio and the coffee grinder to TV signals.
I feel like this video might be him trolling us, he literally wraps like every cable in his house with ferrite lol
@@karlmoore6354 Yeah i was thinking the same thing lol
I have a video as well for ferrites vs stray RF, more or so in layman's terms. This here is a great video too, thorough and precise. 73's✌
Can we use the ferrite cores to filter noise from Mic?
please can you help me !
Rfi Emi ferrite ring suppressor with clip
can i use it on my smart tv?
I have a problem. when I turn on the switch on my closet (which has light savings)
My smart tv blinks.
thank you.
Thank you for the video. Simple yet clear. 👍
We have the same dryer. Worked great. 25 yrs and counting
Is the torroid you used for the mouse cord a magnet?
I bought some clamp-on ferrite noise suppressors, and when I opened one and tried to pickup a small screw expecting it to be a magnet, but it didn't make the screw move at all, so I don't think they are magnets at all.
Hi there. I'm in the UK and I found this video informative. I recently purchased a dash cam with a rear camera unit. When I connected it, my car DAB radio started to be inconsistent. The car (Peugeot) uses the heated rear window as the Aerial (antenna) for the radio. Would using a ferrite on the dash cam cable help to stop this problem? Many thanks.
Great vid.
I have problem from few days ago, when I turn on my LED headlights my radio goes static.
What exaclty should I put through ferrite?
Thanks for the info and help, what do you know on how to quiet mppt solar charge controllers,, ? Thanks 😊
Hi, i have this problem, i usually ride jetski for leisure, but when doing search & rescue, using handheld radios, the problems appeared.
It seems that the reverse cup of the jetski, operated by a motorised servo or actuator, seems to give some interference to the handy talkies. I was wondering & thinking to clip a choke or ferrite at the servo's wiring.
It is a right thing to do? The wires are short & straight, it cant be coiled like i've seen on your videos.
Thanks, from redzall, 9w8arr.
Can you do a video getting into the different sizes and mixes? FT140 vs ft240? I have a ocf dipole 160-10. Do I use 2 choles? one mix 43 and one mix 31? This is where I get confused.
hi. i have led lamps all around in my house which causing interferance in the radio. How do I stop to do it. would ferrite on the radio plug help?
Can these be used on my car radio as dab signal is terrible after I fitted led driving day lights?
If they can help which and where should I fit them
Hi Chris, first of all let me thank you for your video, it has educated me to no end. I have a rfi problem I would like your advice with.
I run a professional music studio and am always trying my best to cut down on noise and interference . Recently I have had a dimmer switch installed on the studios lights. The dimmer switch is an old school MK type double switch not a new led one.. One dimmer for each rooms lighting circuit. I am using new Phillips led warm white bulbs which are great for my studios lighting bills and have been designed to work/dim with regular old dimmers. Indeed the Phillips led bulbs dim perfectly and smoothly, even better using the old mk dimmer than the Chinese led dimmer I had before.
However, now it seems that with the dimmer installed I am picking up much more interference in the room while recording. The classic one is a single coil pickup in a guitar. It goes crazy with interference when the lights are on and then shuts up when I turn the lights off.
Same with guitar amplifiers. Of course I know that guitar pickups and tube amps always pickup interference anyway it's just that the audible volume of said interference has got much louder since I fitted the dimmer.
Please is there any way I can choke/suppress or isolate the dimmer switch in order to reduce the noise/interference without having to sacrifice the dimmer and go back to the standard on full of off switch? Perhaps ferrite beads on the connections to the dimmer? Or do I have to spend a lump on a 1:1 isolating transformer and completely isolate the lighting circuit from the rest of the power in the studio. Any help would be much appreciated. Thank you.
I will answer the question for you. I learned the answer from this video. Take every wire in a 2 block radius and wrap them numerous times around ferrite clips.
Wish I had seen this before. Might have saved me a lot of grief. Thanks
Well done! Thank you for sharing
Thanks
BTW: can you record when you transmitt and you come through the phone, I never saw this live, but heard that you can listen to AM stations on your PSTN telephone
do you know that ferrite changes the cable impedence and that has conseguences on the signal transmitted trought that cable?
Which mix is best for a low pass filter of 100khz or less?
Someone is murdered at 3:10
LOL,
He killed his cat lol ..
or bustin a nut
LOOLLL
^Yeah. It had to be done. The guy said ferrite is useless.
Great video, but anyone with that much trouble with RF on the house, may be in need of antenna adjustments!
Agreed!
Well I'd probably start by putting a decent one at the feedpoint of the antenna. Most wouldn't even know they have CMC issues.
What about if my neighbor has a ham radio that makes my studio go ape shit eveytime he uses it
@@joshthurman7653 I'd cut his antenna wire!
That is what I was thinking too!
Ok so i newly bought wifi and router. So i am starting to have those noise in speakera. Probably its because of router's radio waves. So where should i plug thing Ferrites? I mean on the wifi's wires or speakera wires? Also my speaker wires are smaller in size so winding them with ferrites mike shrink them even more and i need to have my speakers to reach to my woofer in order to work.
hi good day will this work on your car deck?............... when driving i hear a noise playing behind the music......... how can i fix that noise?
I'm not a ham user, but I've always wondered what those things were and what they did. If I ever start picking up local AM/RF interference again, now I know what to do!
This is a guy who has ferrite beads on his shoelaces...
Very well put together video thanks
I have issue which my speaker received RFI, i can clearly hear the radio and its soooo annoying. So where its the best option to put ferrit, speaker power cable or speaker 3.5 jack to my monitor? Please someone help me. Thank you
Awesome !!! New Gen. Licensee here, great practical applications I'm having trouble with.....73, TIM KM4 VGO
Lol I just learned something! Yes, my attention was weakening at the time you mentioned it. Thanks!!! Green video
Hi, i want to use some ferrite chockes on signal wires of a cnc machine. As they have a certain impendance at a certain frequency, other than fitting tightly on the wire, the bigger impendance would mean more efficiency ?
Thank you.
The impedance is resistance to ac current flow, DC signaling passes, but inducted ac signals are suppressed
So I have chokes on everything. My antenna is tuned to less then 1.5/1 I have a common mode choke on the feed line below the antenna. I can not transmit on 40 or 80 without it disconecting my computer from my ft991a. I do not know what else to do.
Excellent simple, straightforward examples. Thanks. K0KK
Does it matter where on the cord you put the far right does it have to be on a certain end or in the middle or it can go anywhere
Will this help my garage door opener from opening by itself? There is a huge radio tower a couple of houses down. This is driving me crazy!!!!!!!!
Can you use both mix 31 and mix 43 on the same coax choke, or does it need to be two separate chokes?
Well you probably could, but I'd just make two separate chokes.
Thanks for this. I'm new to the RFI issue.. never payed any attn to it before. Just setting up a 2m station at the moment. When I key the mike I do have my paper shredder go wild. Also when I had my HP printer closer to the xcvr it would turn on. So, now, shredder disconnected and printer moved a few meters away. That said, what do you suggest for my issue here? I did buy some snap on's that are good to 150mhz per manufacturer. Should I just add a few or more to the antenna coax at the antenna or should I couple that with some coax wraps too? Have no idea what would happen when I try to get onto HF 😊
where is the antenna located and what type?
Hi ! Thanks for the very interesting video. Assuming I'm using a SDR, If I had only ONE ferrite toroid (say FT240-31 ma
terial), on which wire / cable would you recommand to wound it around tu suppress RFI / interferences at best ? Thanks !
IF you're hearing noise in your SDR, you need to choke the source of the noise. You need to find what is making the noise...a "wall wart" transformer, household appliance, etc. and choke its cable.
Thanks for the prompt reply. A few months ago, I tested a basic ferrite clamp (no idea what material it was), and found best RFI suppression when it was wrapped around the antenna coax (between the SDR and the outdoor loop antenna). What does it mean ?
@@aunumero73 probably that the shield of the coax was resonant to that signal you could have eliminated it as easily by changing the length of the coax by cutting it or adding a jumper section
Very informative. So I get radio interference in my plane if I plug a phone cable into one of the two usb ports in the dual usb adapter. One works without interfering the other doesn't. But it only creates interference when I plug in a phone or something to charge. Do you think it would help to put a ferrite around the charging cable or just replace the whole usb adapter?
Yes
Excellent video
This much of ferrite? or is it some kind of OCD?
Perhaps he's selling these things...
Are you a member of the worldwide DX forum?
Yep...you DO require this many for higher power handling and/or higher values not obtainable with just one ferrite. Most info on the subject of Baluns, Ununs, chokes etc., will refer to "more is better" .
How to prevent that one Jammer block the the signal? Any idea??????????
@@rrider993 Yes that's right, for power handling, and for effectiveness. And the right number of turns for the desired frequency, less can be more in choking impedance. Of course the mix is most important too.
Would a ferrite choke stop an EMP pule from coming through the line and destroying equipment?
Was your wive frustrated when she could barely move the mouse? How was it going to plug in and still reach up to the desk?
Crystal clear explanation. Very informative.
I have a question, however.
I'm getting terrible RF buzz on my videos. But not always. Some videos are clean and some have intermittent noise. I'm thinking it's one of my neighbor's cell phones. No?
The cable going into the broadband box? The flat screen computer monitor?
I use a wireless microphone with a lavalier mic.
Any suggestions you might have would be yugely appreciated...
Are you recording video or watching videos when interference happens?
@@alissonmartins1800 This is a blast from the past!
I eventually figured it out. I'd coiled the audio cable to shorten the length. Apparently it emitted an RF signal which interfered with the mic when it got too close to the loop.
True story. I was working at Home Depot back in the 80s - 90s. In Fans and Lighting for awhile. This fellow had a very expensive ceiling fan in his bedroom. Worked off a remote control. Plus the wall switch. He came in a little hot under the collar. Said it was defective because it kept turning on and off at random. He had an electrician look at it. Couldn't find anything wrong with it. Now he's steamed at Home Depot. I had a sudden flash of inspiration. Here in Arizona most air conditioning units are mounted on a concrete slab at the side of the house. Can be at least 10 tons for a 4,000 sq ft house. I told him his unit was on the other side of his bedroom wall. Every time the capacitor discharges to start the motor, it sends out a massive RF signal. He was gobsmacked. I suggested a roll of copper on a sheet of T-111 siding. Worked like a charm. I got lucky on that one....
Are there filters for garage heaters
Any news on my previous question?
How might someone use ferrite for s mobile set up?
Ferrite rocks🤘
Good video man
what is the song at the beginning ?
What's going on if adding ferrites to my speaker cables does nothing but switching to star quad cables fixes the issue?
Awsome advice, thanks
I usually use smaller ferrite chokes and don't wrap several times. But I do not do 2-way radio but only want to get rid of EMF for health and audio reasons. Despite I shielded my PC almost TEMPEST-grade, I hear the CPU and mouse motion as a dull buzz in my tube amplifier. But using ferrite beads with too many turns for the audio wires of the amp itself massively worsened sound quality (harsh trebles, likely by oscillating feedback inside the tube amp or chip output stage of connected media equipment.)
this made me laugh so hard halfway through. I did not see the second half coming.
Okay, so since you know everything, tell us about the common use of ferrite chokes without googling it.
Hola de cuanto es la medida de esos núcleos de ferrita gracias
Priceless...one or two good good ideas. Mind you, self starting sowing machine via RF...Now that's freaky.
73...Karl
VK7HDX
holy crap how did RFI turn the sewing machine on? Did it have a cordless foot pedal or something?
Thank you well done.
can affect bluetooth as well, usb input into my monitor was causing interference until i ferrited it, also a dodgy laptop adapter was part of the problem.
I really got a lot from this video and will need to get better at it. thanks.
This video was funny without meaning to be funny. Whether is the guy getting hit with an arrow at 3:10 or the funny voice imitation, it's funny . But seriously, thank you for the ferrite info, I'm getting a lot of RFI and using chokes to help. 73
Thanks...3:10 was my son playing in the other room with Nerf dart guns.
As a Ham for many years and doing a lot of DX-ing, I've never experienced any of these problems you've described... My antennas are very close to my house. Any thoughts?
Your antennas aren't close enough, lol.
@@KF7P I've an EFLW with the UnUn attached to my house and a trapped vertical (HF) with a dual band vertical (VHF/UHF) next to it, mounted on a 15 ft pole on the second floor balcony... Any other thoughts? (😁)
What haven't you added ferrites to Buddy?
Any pdf file that tackles the purpose of using the ferrite core ?
please share ..thanks
Darrell Lucero download the RFI Ham document in the comments below.
Check out the ones referenced in the video, found in the comments above. Especially RFI-Ham, K9YC.
Thanks very helpful !
Great tips!
my problem is new LED lights. would there be anyway to put one inside light switch. when switch is on you can't hear AM at all.
Not likely, I would replace the the lights with a different kind or try a different brand.
Thanks for the video.
How can I determine choking impedance?
Ever tried this on a guitar cable to try to get rid of EMI noise that gets in?
Great Work
the only time my speaker starts buzzing is when my phone is close to it and I recieve a call... what can I do to stop my phone signal interfering with my speaker?
where can i buy small ferrite cores from
Ebay.
What Ferrite would you recommend me for a Power Supply? like a thermaltake Tought Power 775 bronce 80+
I mean a ferrite for protect the Power supply cable that is connected to the wallets
Also a ferrite to supply those Molex, PCIE, cables that are connected to the psu insidE?
Help plz, nice video
Sorry for my English im from Venezuela.
"Gracias" Thanks WP4CNA
good vid but Mix 31 is the latest development for noise suppression that covers the broadest frequency range of 1 - 1000 MHz and you can use it to stop noise from getting into your radio from switching power supply's of all kinds. the little wall warts from cell phones are switching supply's and so on.
If your amateur radio equipment is causing so much RFI I think you should really do an RF ground not an electrical ground but RF ground most amateur radio operators forget to ground every piece of equipment to a center bus out to an 8-foot ground rod using ground straps that should be as short as possible and never equal a quarter wavelength of the highest band. Also one more thing if you are running a dipole Orin off-center fed antenna it should be as high as possible also.
Exactly, he has issues with his equipment
Question - how/why so many affected/affecting devices? RFI (from TX, and into RX) starts at the transmitter, the feed and antenna systems +/- grounding/bonding and common-mode issues.
26 years of HF operation at present QTH. Station implemented from the ground up, literally, per Ward Silver's best practices and Motorola R56. Neighbors within 30-40 feet of some antennas. Several different domestic appliances/systems, solar, many PCs and associated networking. Station never affected by any household/consumer devices. Station never affected any devices.
Thank you thank you thank you 🙏🏻
I used ferrite chokes for my Bosch fridge. Suppresses the interference.
Every time I transmit (just 10 Watts), my computer has some USB devices disconnect/reconnect. Putting as many ferrites as possible may be the solution... but looks like I need a hundred of them just for the dozens of USB cables on my desk. Also some devices may not have long enough cables to wrap around multiple times.
You can also try using a longer or shorter cable, or plug those devices into a hub, and then use a cable with a ferrite between the hub and PC, try to not have coax and PC/power cables running parallel with each other, perpendicular is best
When I lived in a house where some kids had a walkie talkie, my Amiga (build into big wooden custom case) started to type random characters when they were transmitting. I had to always move the keyboard cable until it went away.
oh man, i forgot about this video :D
for real though, you can never have enough ferrite.
Interesting, but can't even find a place to buy ferrite/chokes where i am. VE7ZU.
May I ask you a very serious question? Does your wife really talk like that?
I love real world, practical videos like this… Thank you for taking the time to produce it
LOL
Sewing machine would run by itself :)
Either antenna adjustments or trim back on the Fat Boy output. Seriously though, I quit radio for a while...press release pointed to the unindicted causing splatter on neighborhood boob tubes and squawk boxes. Rumor has it a sewing machine made a wedding dress all on its own. I'm back, running barefoot and boxers only.
Most wives would throw that ferrite you placed on their mouse right back at you.
Whodathunkit? Got a major noise problem on a new HF radio installation now. Time to get, *"The Book!* Might just order the ferrite though.
Nice piece from KA1XK/7