Living in a noisy world.

[KD1SH]

   Yesterday afternoon, on 3873, I was plagued by some very nasty broad-band RFI; the worst I've had in a long time. It appeared on my spectrum display as regularly spaced swaths of "fuzz," accompanied by a very annoying buzzing sound. Unplugging everything I could think of, all the usual suspects, led me nowhere. I even went outside and shut down a couple of solar-powered motion sensor lights on my front porch, but to no avail. I've seen this before, but never this severe. I was beginning to worry that it was coming from a neighbor's house down the road, which has a huge steerable array of solar panels in the back yard. Great, I'm seeing the beginning of the end of my radio hobby!
   Okay, let's try one more thing...I unplug my "smart" battery charger, which sits on my desk right next to my computer and normal operating position. Silence! Wonderful, golden, silence! It's a Nitecore D4, a nice little charger, but apparently whatever switch-mode stuff is going on in there, or maybe the microcontroller's clock, is performing a concerto in there. The weird thing is that when I plugged it back in, the noise was gone. It seems that it gets itself into a tizzy, and stays that way until power is cycled.
   There was a time when we hams were the convenient whipping-boys for every line of static that appeared on every neighbor's television, or every crackle heard on a stereo (it's that stupid guy down the street with that stupid ham radio again!), but now it seems everything in the world is screaming at us.

[KA3EKH]

My brain gone soft over the years and don't remember much of Maxwell but am fairly certain field density decreases as an exponent of distance.  Local noise sources are always worst. I have one of those Chinese GPS 10 MHz references for locking up all the junk on the work bench. It not only kills local reception of 10 MHz WWV but also generates S9 noise on sixty meters. 

[W1RKW]

Bill, I have the same charger and I have noted the same issue you're experiencing. Like you, I just unplug it when done using it.  I have no idea why it does what it does but disconnecting is an easy solution. Considering where it's made it's probably best to disconnect it anyway.   

I am plagued with an unusual noise problem that I have yet to figure out. It's a unique noise at least to me. It occurs on 10m. It seems maximum on 10m. It diminishes as one goes up and down from 10m.  It sounds like wind blowing across your ears at 60mph if you stick your head out the window when in AM mode. It occurs every 80kHz up and down the 10m band and is about S5 or S6 and has a bandwidth of about 15kHz.  It's not originating from my QTH after shutting everything off completely in a recent power outage and running my rice box on battery. I think it might be someones solar array in my neighborhood. the noise goes away once the sun goes down.

[WQ9E]

Bob,

Don't overlook the other source of noise that disappears when the sun goes down.  A lot of solar light controllers partially but don't fully shut off power to the controlled device when illuminated and that can create incredible noise.

I have a very quiet rural location but several years ago I had a lot of daytime buzzing showing up mostly on 15 meters with fairly stable broad ares of noise.  It was a stupid nightlight with a light sensor that created incredible noise in any condition except strong light or full dark.

A few months ago I put a ambient light controller on the LED lights I use on the gazebo and I chose one that uses a relay to control the load.  It is quiet (well except for the click the relay makes if you are standing next to it when the sun sets )

Rodger WQ9E

Rodger WQ9E

[W1RKW]

thanks for the tip, Rodger.  Now that I think about it, I do have one solar powered flood light. Good catch. I'll have to look into that. thanks.

[AJ1G]

The most significant environmental EMI here is from my immediate neighbors?s grid tied solar electric inverter mounted on the outside of his house near his service entrance about 100 feet from my dipole and vertical antennas in my back yard.  EMI includes nominal 200 kHz spaced harmonics of what sounds like FSK data, on 75/80 meters  they are just below 3600 3800 and 4000 kHz. Also swaths of broadband energy generally in the  lower end of the 80 meter band.  The worst interference occurs on 40 meters with near S9 levels of 60 and 120 Hz spaced discretes all over the band.  Thankfully no interference at night, early morning, and evening  hours.  Absolutely worst at solar noon when the solar panels are at full strap output.  Also much lower levels of the EMI on cloudy/overcast days.  

A few months ago, the solar power system was shut down and while the panels were removed while the neighbor?s roofing shingles were replaced (almost every house in the neighborhood , including ours, has had their roofs replaced due to damage from a severe hail storm  in mid last August).  With the system shut down, 40 meters was amazingly quiet here, just S2-3 white  noise.  For a week of so after the panels were replaced it was still quiet, but then all the interference came back as bad as ever.  Apparently there was a delay in putting the system back  on service.  Similar interference can be heard in my mobile while driving around the neighborhood in proximity to all the other homes that have the same type of grid tied systems

Considering the cost of electricity here in CT lately, I would really like to install a solar system myself, in particular a battery storage backup system that can be run independent of the grid.  Would be interested in hearing about any such systems which have  acceptable low or insignificant EMI impact if such systems actually exist.

We installed a Mitsubishi HyperHeat high efficiency mini split heat pump heating and cooling system in the spring of 2023.  Two 30K BTU compressors each with 3 indoor wall mounted units.  I was concerned about them as a possible EMI concern.  I  used metal conduit for the branch circuits powering the compressors from the main power panel all the way to compressors and have absolutely no detectable EMI from the system.  One of the compressors is located less than 10 feet aaay from my from my basement radio shack and the coax feeds from my antennas pass by it within only couple of feet.  

Had a conversation with Chuck K1KW, who has 4 Mitsubishi compressors at his place and has conducted extensive conducted and radiated EMI measurements of them.  He told me that the Mitsubishi systems are among the best available EMI-wise.

[AJ1G]

Re the solar powered flood lights, are they the stand alone type that have internal rechargeable batteries and 3 replaceable C cell batteries  for backup?  We have 5 of those motion sensor type security lights, never considered they might be a possible EMI source.

[KD1SH]

   Battery chargers can be nasty things in more ways than RFI. Lithium-ion batteries can burn like hellfire for a number of reasons, and I would never, ever, leave them charging unattended. A neighbor of mine lost his garage/workshop a few years ago, burned to the ground, and he blamed it on a rack of battery chargers, with cordless-tool batteries always inserted and charging. He said he didn't know anything was going on until he heard "POP! POP! POP! and looked out the window to see fire roaring out his workshop (fortunately not attached to the house, but close enough so that it's amazing that the house didn't go as well). He told me that he kept an assortment of aerosol cans, WD-40 and cleaning solvents and such, right next to the battery chargers on his bench, and figured that the pops were the cans exploding after the batteries flared up.

Bill, I have the same charger and I have noted the same issue you're experiencing. Like you, I just unplug it when done using it.  I have no idea why it does what it does but disconnecting is an easy solution. Considering where it's made it's probably best to disconnect it anyway.   

[K8DI]

   The weird thing is that when I plugged it back in, the noise was gone. It seems that it gets itself into a tizzy, and stays that way until power is cycled.

I've seen this with a variety of SMPS chargers and supplies -- they don't start making noise until they deliver current the first time, it's like they don't start oscillating until you connect a load, and then continue to oscillate when the load is removed....

Had a huge offender here (S9+20 on 80m), in a charger for a motorized scrub brush. I threw the charger away when no one was looking, but it was eventually noticed. The replacement (from the same company) is dead quiet. Different lot, fewer parts left out by the cheap manufacturer? Not certain, but thankful the newer one is quiet...

Ed

[KD6VXI]

Get some type 31 ferries and start winding some chokes.

That's the only way to get this switching crap fixed.

The solar system at the neighbor could have a couple fixes.  If it's a central inverter with no optimizer then a type 31 common mode choke on the DC input and on the ac output usually quiets most inverters down.

If it's one with optimizer, you have to choke every single optimizer as well.  Elon Musk was nice enough to install hundreds of thousands of square wave generators on peoples houses for us!!!!!  ( as well as other companies, but I digress).

Micro inverter technology, same thing.

They do make quiet solar installations.  You either buy quiet equipment or mitigate the noise with a ton of type 31 ferrite cores.

The other thing that somewhat runs with the sun is marijuana grows.  They are using digital square wave ballast now.  Much cheaper but horrid generators of noise.  Those are easily found with either 18 hours of on and 6 hours of off or 12 on 12 off.  Different light cycles for different grow times.

So much fun.  Not.


--Shane
WP2ASS   / ex KD6VXI

[Opcom]

It's a Nitecore D4, a nice little charger, but apparently whatever switch-mode stuff is going on in there, or maybe the microcontroller's clock, is performing a concerto in there. The weird thing is that when I plugged it back in, the noise was gone. It seems that it gets itself into a tizzy, and stays that way until power is cycled.

That Nitecore is, regardless of noises, one of the chargers I am most confident in, for not overcharging the Li-ion batteries. It seems some actual care went into its charging profiles/detection and design. It charges a wide range of cells tho I use it for 18650s. None of my cells so far are the 'safety' kind so I'm picky about chargers. Mine's hot pink LOL ! came with a vape device which i no longger use - quit all smoking and
' tobacco juice' etc.

I believe the Nitecore name is after "Nightcore" (also known as sped-up song, sped-up version, sped-up remix, or, simply, sped-up edit) is a version of a music track that increases the pitch and speeds up its source material by approximately 35%. This gives an effect identical to playing a 33⅓-RPM vinyl record at 45 RPM.

The name is derived from the Norwegian musical duo "Nightcore" (Norwegian pronunciation: [ˈnɑɪ̯tkɔːɾ]), who released pitch-shifted versions of trance and Eurodance songs. Videos are also Nightcored.

The charger does not speed up the charging as it would be dangerous.

[W1RKW]

Re the solar powered flood lights, are they the stand alone type that have internal rechargeable batteries and 3 replaceable C cell batteries  for backup?  We have 5 of those motion sensor type security lights, never considered they might be a possible EMI source.

Chris, it is one of those cheap big box store solar powered flood lights. Batteries are not "replaceable".

[KD1SH]

   None of the websites that sell the D4 mention that it's available in hot pink, so I figure it must have been a special edition for inclusion with "vape" products. It is indeed a superb charger, in any color. The only complaint I have (other than the RFI) is that even though it's supposed be able to charge 26650's, the maximum length of the bays is just barely sufficient, and 26650's that are just a few thousandths longer won't fit. I have two of those batteries; one will fit in the D4 and the other will not.
   Some of my 18650's are "protected" types, and others are not, and like you say, being picky about chargers is a very good thing when charging those.
   My favorite "smart" charger is a Maha MH-C777plus-II. It will not only charge, but will perform a controlled-discharge and recharge, to "condition" and test batteries. The only problem with the Maha is that you might need to get creative when it comes to holding the typical cylindrical batteries like "C" and "D" sizes and 18650's and such. With a "bay" charger like the D4, it's easier. But, for charging odd-shaped battery packs, like those for amateur radio HT's, the sliding contact points are versatile.
   "Nightcoring" musical recordings...interesting stuff; never heard of that before. Yes, doing the same thing with battery charging wouldn't be a great idea.

That Nitecore is, regardless of noises, one of the chargers I am most confident in, for not overcharging the Li-ion batteries. It seems some actual care went into its charging profiles/detection and design. It charges a wide range of cells tho I use it for 18650s. None of my cells so far are the 'safety' kind so I'm picky about chargers. Mine's hot pink LOL ! came with a vape device which i no longger use - quit all smoking and
' tobacco juice' etc.

I believe the Nitecore name is after "Nightcore" (also known as sped-up song, sped-up version, sped-up remix, or, simply, sped-up edit) is a version of a music track that increases the pitch and speeds up its source material by approximately 35%. This gives an effect identical to playing a 33⅓-RPM vinyl record at 45 RPM.

The name is derived from the Norwegian musical duo "Nightcore" (Norwegian pronunciation: [ˈnɑɪ̯tkɔːɾ]), who released pitch-shifted versions of trance and Eurodance songs. Videos are also Nightcored.

The charger does not speed up the charging as it would be dangerous.

[W1RKW]

we just had a new washing machine delivered this morning.  It replaced a 39 year old Maytag which had mechanical timer and controls. The pump on it seized burning the belt and stressing the motor windings. I told my wife its time to go. I repaired it twice in its life. One set of belts and a solenoid valve is all it needed over the years. It didn't owe us anything. the thought of repairing it again wasn't in the cards since many critical OEM parts are no longer available. So out with the old in and in with the new. 

I wanted to get a commercial Speed Queen which had mechanical controls and timer but the XYL didn't want to spend the $$ so we ended up with another Maytag, a micro controller controlled Maytag for a lot less cost.

I was apprehensive to go with the new Maytag for 2 reasons. One: My mother has a similar machine and it has eaten 2 clutches in a years time out of the box.  So far that's been OK on clutch #3.  But the 2nd reason I was apprehensive was the micro controller and EMI/RFI.  Running laundry right now and the bands are quiet and very quiet too. No hint of interference whatsoever.  So no RFI/EMI issues with the new machine. The bedside receiver is the next test. 

One thing I did not consider with the noise issue I mentioned above is the XYLs car is a hybrid. I need to look into that as an interference source when garaged.

[KD1SH]

   We bought a new electric kitchen range a few years ago, and I made sure we got the most unsophisticated model available; it has only an old-fashioned analog clock in the middle of the rear panel. I'm sort of retro, anyway, so it's cool.
   I'd worry less about laundry washers and dryers, since I could always just unplug them when I'm on the air. Stoves and microwaves are more problematic since you'd probably be less inclined to unplug them all the time and thus have to reset the clocks. Likewise for home entertainment stuff. I have a watch, and a real analog clock on the wall; do I really need to look at my stove or microwave to see what time it is?
   The day will probably come when we're getting interference from embedded microcontrollers in our toothbrushes and toilet-paper dispensers.

we just had a new washing machine delivered this morning.  It replaced a 39 year old Maytag which had mechanical timer and controls. The pump on it seized burning the belt and stressing the motor windings. I told my wife its time to go. I repaired it twice in its life. One set of belts and a solenoid valve is all it needed over the years. It didn't owe us anything. the thought of repairing it again wasn't in the cards since many critical OEM parts are no longer available. So out with the old in and in with the new. 

I wanted to get a commercial Speed Queen which had mechanical controls and timer but the XYL didn't want to spend the $$ so we ended up with another Maytag, a micro controller controlled Maytag for a lot less cost.

I was apprehensive to go with the new Maytag for 2 reasons. One: My mother has a similar machine and it has eaten 2 clutches in a years time out of the box.  So far that's been OK on clutch #3.  But the 2nd reason I was apprehensive was the micro controller and EMI/RFI.  Running laundry right now and the bands are quiet and very quiet too. No hint of interference whatsoever.  So no RFI/EMI issues with the new machine. The bedside receiver is the next test. 

One thing I did not consider with the noise issue I mentioned above is the XYLs car is a hybrid. I need to look into that as an interference source when garaged.

[WA2SQQ]

To everyone, if you are experiencing noise related to solar installations, read on. If you can verify that they are using Solaredge hardware, I have a contact at Solaredge that has been very cooperative. My neighbor had a system installed which obliterated the AM section of 40m. They installed new optimizer cards which was part of their newly designed system. They?ve been back two more times to do more updates.

So far, 40m is good. Reach out to me
(My call) at gmail