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[K0UA]

Now we have a name to blame for the rapidly increasing noise floor caused by the invention of the switch mode power supply. And he is actually very proud of his invention.

https://www.electronicdesign.com/technologies/boards/article/21795586/robert-boschert-a-man-of-many-hats-changes-the-world-of-power-supplies#:~:text=Robert%20Boschert%20has%20worn%20some,usage%20switching%2Dmode%20power%20supplies.

[W6QW]

Boschert's switching PS's were well designed products and were RFI free.  The problem, as everyone knows, is the commoditizing of switching supplies, coupled with the literal disregard of good engineering practices in favor of low cost outcomes created the monster offspring from Mr. Boschert and the other pioneers in switching PS technology. 

But, since you have now published his identity, he will be forever blamed by hams for the pain and suffering that has fallen upon our airwaves and I anticipate demonstrations will begin at any time..

[K6AER]

The bottom line is cost. This is always the driving factor in product development and potential for increased sales. The RF spectrum is unknown to 99% of the public. Part 97 requires the signal level in the 1-1000 MHz band to be below S9 at 100 feet. That and for every time the noise source numbers double the noise floor increases by 3 dB. Given the number of cheap supplies, LED lightning, and now home solar, it is a wonder we can communicate with radios at all.

I live out in the country and still my biggest problem with noise is power lines, In the country the top line voltage is 14.4 KV. Twice as high as the city which typically is 7.2 KV. Power is the voltage squared into the load resistance. A bad connection on a power line can be herd for 5 miles in some cases.

I am on HF mostly and when I call CQ on 20 or 40 meters, with 100 watts, it takes an average of 6 CQs before someone answers. Call CQ with the amp on and  70% of the time several stations will call back on the first CQ. When I ask what their noise level is they tell me it is between S7 and S9.

The bands are improving and that will help the signal to noise ratio, but out digital noise problem is not going away.

[K6AER]

But, since you have now published his identity, he will be forever blamed by hams for the pain and suffering that has fallen upon our airwaves and I anticipate demonstrations will begin at any time..

Only if he is a Republican.

[K0UA]

I agree, our noise floor issues are not going away, and in fact are getting worse and an exponential rate.  I have to use great care to monitor each and every electrical appliance and device brought into the home and evaluate if we are going to keep it or send it back for excessive RFI.  But I cannot control my neighbors homes and what they bring into them.

  And yes, of the hundreds of guys I have assisted with setting up their stations, I have asked them what is their resting noise level on 20 meters, and the common answer as said above is S7 to S9.  Some are better off, but MANY are not. No wonder they are so disappointed at how poorly SSB seems to perform at their locations.

 This has driven many to CW and digital modes as a way of dealing with terrible noise. I can remember as a young man getting started in Amateur Radio and living out in the country, we actually concerned ourselves with the concept of receiver sensitivity. Now we don't have to worry about that at all. Now we need to be thinking about how good is the attenuator system and RF gain controls so we can back down that sensitivity to the existing noise floor.

[AC2EU]

I agree, our noise floor issues are not going away, and in fact are getting worse and an exponential rate.  I have to use great care to monitor each and every electrical appliance and device brought into the home and evaluate if we are going to keep it or send it back for excessive RFI.  But I cannot control my neighbors homes and what they bring into them.

  And yes, of the hundreds of guys I have assisted with setting up their stations, I have asked them what is their resting noise level on 20 meters, and the common answer as said above is S7 to S9.  Some are better off, but MANY are not. No wonder they are so disappointed at how poorly SSB seems to perform at their locations.

 This has driven many to CW and digital modes as a way of dealing with terrible noise. I can remember as a young man getting started in Amateur Radio and living out in the country, we actually concerned ourselves with the concept of receiver sensitivity. Now we don't have to worry about that at all. Now we need to be thinking about how good is the attenuator system and RF gain controls so we can back down that sensitivity to the existing noise floor.

Well designed switchmode power supplies aren't problem. The real good ones even have a PFC circuit so as not to cause a power factor issue.  It's the non compliant junk that gets imported here and sold despite the RFI.

I use SMPS supplies in the shack to power radios. My noise floor is almost nill because I live in the sticks.

The worst offenders are cheap smps driven lighting products and Plasma TV sets where have thankfully gone obsolete.
i know a contractor who had to rip out all the LED inverters they installed in a prison because they were creating too much RFI and hampering communications! They replaced them with good quality compliant ones and the problem was solved.

[W9IQ]

Part 97 requires the signal level in the 1-1000 MHz band to be below S9 at 100 feet.

There is no such Part 97 provision.

- Glenn W9IQ

[KF5LJW]

Part 97 requires the signal level in the 1-1000 MHz band to be below S9 at 100 feet.

You are clearly mistaken. No such rule exist. You are making it up.

I live out in the country and still my biggest problem with noise is power lines, In the country the top line voltage is 14.4 KV. Twice as high as the city which typically is 7.2 KV. Power is the voltage squared into the load resistance. A bad connection on a power line can be herd for 5 miles in some cases.

One has nothing to do with the other. Secondary distribution voltage in the city or rural can be as low as 1.3 Kv up to 30 KV.

[KC6RWI]

Most of the house hold machines made in the UK and USA that had carbon brush motors made in the 50's 60's and later had electrolytic capacitors to eliminate noise.
I don't know why they were eliminated, maybe the feeling was the radios and tv's are more resistant to noise?

[VK5ISO]

Unfortunately, the problem is global: down here in Australia, it is as bad if not worse than in the US, since most, if not all our electronics is imported from China and is, unfortunately, very badly shielded, if at all.

Just how bad things had become was  obvious during the state-wide blackout of 2016 in South Australia, where I live.

 I run my radios of  LiFePo4 100Ah  batteries and  was simply floored: during the blackout, there was literally no noise at all on most bands (we're talking S1-S2, whereas normally it is S7-S9 depending on the band and the time of day). I could  see why sensitivity was the main issue for radios produced into the 1970s or even 1980s.

Now, frankly, CW and some of the digital modes  have become the  only realistic way to operate for me.

 I  operate multiple digital  noise reduction systems, several of the receiving antennas are magnetic loops ( one excellent 2m varicap loop antenna designed by Ciro Mazzoni as well as   two  1m Welbrooks, running through an NCC-1 variable phasing controller).

It's a real pity!

[K0UA]

Unfortunately, the problem is global: down here in Australia, it is as bad if not worse than in the US, since most, if not all our electronics is imported from China and is, unfortunately, very badly shielded, if at all.

Just how bad things had become was  obvious during the state-wide blackout of 2016 in South Australia, where I live.

 I run my radios of  LiFePo4 100Ah  batteries and  was simply floored: during the blackout, there was literally no noise at all on most bands (we're talking S1-S2, whereas normally it is S7-S9 depending on the band and the time of day). I could  see why sensitivity was the main issue for radios produced into the 1970s or even 1980s.

Now, frankly, CW and some of the digital modes  have become the  only realistic way to operate for me.

 I  operate multiple digital  noise reduction systems, several of the receiving antennas are magnetic loops ( one excellent 2m varicap loop antenna designed by Ciro Mazzoni as well as   two  1m Welbrooks, running through an NCC-1 variable phasing controller).

It's a real pity!

As the old song says, "you don't know what you've got till its gone".

Yeah, I bet that power blackout was a real eye opener. The noise floor rises just a little each day with each new piece of junk added to the neighborhood. It is kind of like the old axiom about boiling a frog in a pan of water. The temp rises slowly and he never notices.

It amazes me that the general public and governments care greatly about many kinds of environmental pollution, but cares nothing about electromagnetic pollution. We are the canaries in the coal mine, but no one is listening or watching us fall off of the perch.

[KF5LJW]

ade in the 50's 60's and later had electrolytic capacitors to eliminate noise.
I don't know why they were eliminated

Because the world moved on to more efficient and powerful DC Brushless and AC Induction motors. Where have you been for 40 years? Ironically DC Brushelss motors are not DC.

[KC6RWI]

The majority of machines I repair daily for over 50 yrs have carbon brush motors, in fact some of the machines have 2 motors, one that runs on 120 ac and another carbon brush motor that runs on 12v dc.
Now if you are talking about consumer electronics,i don't think I've ever seen a carbon brush motor in a vcr  dvd player.
I'll make a correction on that, most of the loading motors in vcrs are carbon brush.

[K1FBI]

I agree, our noise floor issues are not going away, and in fact are getting worse and an exponential rate.  I have to use great care to monitor each and every electrical appliance and device brought into the home and evaluate if we are going to keep it or send it back for excessive RFI.  But I cannot control my neighbors homes and what they bring into them.

  And yes, of the hundreds of guys I have assisted with setting up their stations, I have asked them what is their resting noise level on 20 meters, and the common answer as said above is S7 to S9.  Some are better off, but MANY are not. No wonder they are so disappointed at how poorly SSB seems to perform at their locations.

 This has driven many to CW and digital modes as a way of dealing with terrible noise. I can remember as a young man getting started in Amateur Radio and living out in the country, we actually concerned ourselves with the concept of receiver sensitivity. Now we don't have to worry about that at all. Now we need to be thinking about how good is the attenuator system and RF gain controls so we can back down that sensitivity to the existing noise floor.

Spot on! I use my attenuator and RF gain and it's a beautiful world again. I don't care what the single actually reads. If you sound like you're across town and I don't have to ask you to repeat anything, you get a 59 signal report from me.

[N6YWU]

Part 97 requires the signal level in the 1-1000 MHz band to be below S9 at 100 feet.

There is no such Part 97 provision.

- Glenn W9IQ

So what's a typical S-meter reading, 98.43 feet away for something throwing 30 microVolts/Meter of RF into some HF band via A/C power cord and/or USB cable (etc.) antennas?