Hey you need to get an amateur radio license at least a general license !

The reason to get a license so you don't create RF problems for us radio operators.

KI7CSN said:

The reason to get a license so you don't create RF problems for us radio operators.

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A general license is a lot to ask of people who don't plan to use a radio. That's takes a good handful of hours of studying and test prep doesn't it?

Any advice on the best way to learn/study for it for those that are interested in it?

Any general pointers on how not to create RF problems for Hams?

Dzl makes a great point for Dennis' complaint.

While I understand the frustration I believe the proposed solution is not helpful.

As someone who got their Novice License back in 1972 (when there was such a thing) and have held an Extra Class license for more than 30 years I know a little about what is in the FCC test question pool. IMHO far less than half of the material would help with awareness of RF noise.

To point out the problem I would let non-Ham radio folks know that the Solar community is the worst offender that I am aware of. The specific worst offenders are Solar Charge Controllers and Inverters that generate a TON of RF (Radio Frequency) noise. This has ruined the hobby for some folks who went from a baseline of S zero noise in their neighborhood to as much as S nine noise! Since this is a logarithmic scale the increase is almost unimaginable. Plasma TV's and SMPS "wall warts" are other huge offenders.

My best guess is that awareness of the problem is the first step. To impact the problem in a favorable way is going to take a few RF suppression components added to SCC's and inverters. Solar folks are almost as frugal as radio folks so that will likely be a problem.

I am going to mentally chew on this problem for a few days and then hope to start a thread about education about and solution of the problem.

73,

Joe

Yes this is something I had no clue was a problem. I think methods and remedies discussed in the forum would be a good thing.

I have noise problems with my neighbor's new high efficiency HVAC system. What I learned in my research shocked me. For these products to become legal for use in the US they only have to meet noise standards above 30mhz. Below that and anything goes. So on the 10 meter band and below I get waves of interference up to S9, where before I'd see S2-3. I've tried various chokes and ferrites without much success. I have no problems on the upper bands.

I found that the new high efficiency HVAC systems use variable speed motor controllers which causes the problems. I forget if it was PWM or switching power supplies, but similar things to what we use in solar...

I think a big contributor on the solar side is HF inverters...LF inverters are much cleaner.

It doesn't help that the FCC doesn't seem to care.

KI7CSN said:

The reason to get a license so you don't create RF problems for us radio operators.

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Perhaps you need to quit adding signal to my noise.
I like my noise noisy, thanks.

Interesting discussion.

Warning: Speculation follows.

The solar charge controllers are in the perfect position to cause problems. Imagine a PWM controller switching high current. This will naturally make a lot of RF noise. That noise will have a perfect path back up the wire to the solar array. That wire and array will act like a nice antenna to broadcast the noise. Even if the SCC is not generating noise, it can still be a path from the inverter to the 'antenna'.

I suspect a few strategically placed ferrite coils could go a long way to suppressing the noise, but the average solar DIY'r is not going to know what Ferrite coil to use or where to place them.

I'm guessing here but from the videos I have seen EMC is a very involved science, and, therefore, expensive for product development and testing. If there is no legislative reason to do this (thoroughly) then why would a product manufacturer invest in doing do? We live in a capitalist society, never has that been more evident when you consider the globalization of trade, particularly where China is involved.

My guess: buy from China, expect RF noise. Simple as.

And that is never going to change without legislation that might impact a company's bottom line.

SolarRat said:

I found that the new high efficiency HVAC systems use variable speed motor controllers which causes the problems. I forget if it was PWM or switching power supplies, but similar things to what we use in solar...

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For AC motors they use what is called a VFD (Variable frequency drive). What a VFD does is to convert the AC power to DC and then re-create a modified sine wave AC at different frequencies using Pulse Width modulation. These things are notorious for being noisy. In some industrial controls, they have to put in chokes just to suppress the noise enough to allow the rest of the system to function.

tictag said:

I'm guessing here but from the videos I have seen EMC is a very involved science,

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Even with all the science, there tends to be a lot of guess work to figure out what is generating the paths for the noise and a fair amount of 'art' in figuring out what to do about it. It tends to be a very specialized field that even most well trained electrical engineers don't fully understand.

Yes, it is expensive to do the tests... and perhaps more expensive to rework the product and retest.

Sandman said:

How would having a license stop noise? What is Ham radio used for?

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A lot of getting a Ham Raidio license involves showing that you know radio electronics... and that means you have to learn a lot about RF and RF Noise. The OP is assuming that if you have the license you know the electronics and would do things to prevent the noise coming from your system. I am not convinced that is a safe assumption.

Sandman said:

This question comes from ignorance: What is the purpose of ham radio? I don't see it as that important (I could be wrong), while people make great use of solar power every day. If calories are going to be burned, I think the Hams should figure out how to deal with the noise.

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ham=amateur radio.
They serve a vital function when there is a natural disaster or similar.
Asking solar installations to be license ham operators is a real stretch and I doubt the OP was serious.
Neither was I in my initial response.

Sandman said:

If calories are going to be burned, I think the Hams should figure out how to deal with the noise.

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I am not a ham operator, but I don't think that is a viable solution. The Ham radio enthusiasts are picking up faint signals from around the globe. If there is a lot of RF noise at the same frequency as the signal, that becomes almost impossible to do. Saying the ham radio operator should learn to deal with the noise is like someone playing music at rock-concert levels in a neighborhood and saying the neighbors should figure out how to deal with the noise. There is not much the neighbors can do.

I am never one to encourage more government over-site, but I am afraid @tictag is right. The only solution to this is for the government to put in limits on the noise the equipment is allowed to generate.

Sandman said:

This question comes from ignorance: What is the purpose of ham radio? I don't see it as that important (I could be wrong), while people make great use of solar power every day. If calories are going to be burned, I think the Hams should figure out how to deal with the noise.

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You'd be amazed at what happens on ham radio. There are all manner of encrypted digital signals, also unencrypted ones. You can decode NOAA weather facsimiles over ham (HF radio). Airliners out of the range of control towers use ham radio (HF Aeronautical). Weather services broadcast reports to aircraft (VOLMET). Amateur radio operators of course use it. FT8 is a popular method of communication now that uses extremely low power and can be received even in noisier environments. The military uses ham radio in case the satellites go down and you can hear things like the Air Force Emergency network broadcasting every now and then.

Spies use ham radio. Google "Numbers Stations". Countries use shortwave radio to send news and propaganda to other countries. Can't swing a dead cat without hearing CNI (China) on shortwave. I could go on and on and on.

I can also go on and on and on about RF. Since I started with the solar my RF levels are way up (on some radios). I can use my house outlets okay to power a radio but FUGGETABOUTIT for using a power strip hooked to an inverter.

John
KN4FMV

BTW: I have not been involved in the RF noise issues for quite a long time, but back in the 80s and 90s there were some pretty stringent requirements about noise generation. I had to jump through hoops to ensure my designs were within spec. However, I never once heard of a situation where the government actually tested or enforced the specification. I suspect a *lot* of the equipment sold does not meet the existing requirements on noise generation.

Long ago in another life I worked on a small electronic device that was to be certified for home use.
It gave off too much rf noise so we got it certified for "office" use or something similar, I forget the exact words.
Our product shipped as such and I am sure > 80 % ended up in homes.

smoothJoey said:

Long ago in another life I worked on a small electronic device that was to be certified for home use.
It gave off too much rf noise so we got it certified for "office" use or something similar, I forget the exact words.
Our product shipped as such and I am sure > 80 % ended up in homes.

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Yup. My company would not let me do that, and it frustrated me because of all of the competitors doing it.
It goes to show how a law that is not enforced is nearly meaningless.

Break it up.

In my past life, in a galaxy long ago, I trained for and spent a good deal of time chasing and usually curing RFI, (Radio Frequency Interference).

Sometimes transmitters were over modulated or otherwise drifting off frequency, (though off frequency is more rare due to the advent of modern Phase Lock Loop nechtology).

Sometimes the interference was caused by the mixing of more than one transmitting signals in the air and/or in the transceiving equipment, which created an interfering frequency that was on or near channel enough to cause interference.

Sometimes the RFI problems rode into town on copper phone lines, coaxial lines, satellite links, wi-fi and bluetooth transceivers, equipment housings, yada.

Sometimes the offending transmitter was legally putting out so many watts of power and was so close to other residences, that there wasn't much that could been done besides beg the neighbor to coordinate their hours of broadcast with your re runs of Knotts Landing, or in extreme cases, study the sabotage tactics of the Ninja AND TELL NO ONE. (Not recommended - do not do that - just joking).

I remember one day my next door neighbor told me that his electric garage door went up when jets were on approach directly overhead and sure enough I saw it happen! RFI

I remember being in another garage with an electric door opener and when I squeezed the trigger of my cordless drill, the spurious harmonics created by the drill's electric motor activated the garage door opener! Again, another form of RFI.

There are a myriad of products designed to combat RFI and in this world where we are fascinated with allowing every Wild World Web hacker, (including Auntie Samantha, {uncle Sam's wife}), into our homes to monitor our conversations and see into our refrigerators and bedrooms via RF connected devices, there's bound to be more RFI to contend with.

Smart meters, smart phones and GWA, (General Wireless Addiction), has immersed us in a veritable soup of RF and we are the noodles.

Below: Who is interfering with whom is often a two way street but the best policy is to work together to solve RFI.
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I'm surprised more posters here aren't hams. I'd figure off-grid living and backup forms of communication would go hand in hand.

That said, I don't think the average DIYer here would pass the tests...but a GMRS radio/license is cheap and easy, and perfectly usable for short range communications...and it uses frequencies well above most RF noise.

SolarRat said:

I'm surprised more posters here aren't hams. I'd figure off-grid living and backup forms of communication would go hand in hand.

That said, I don't think the average DIYer here would pass the tests...but a GMRS radio/license is cheap and easy, and perfectly usable for short range communications...and it uses frequencies well above most RF noise.

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