FCC Public Notice DA 16-676 Noise Floor Technical Inquiry

[k3msb]

http://transition.fcc.gov/Daily_Releases/Daily_Business/2016/db0615/DA-16-676A1.pdf

[WD8KDG]

From a lay person:

My eyes are rolling

From a technical view, how does one measure the "Noise Floor"? Is there an industrial standard,..........? Where does one start a base line, year 1955?

"You have to be kidding" ...................now heading back under my rock.

Craig,

[DMOD]

I think the problem will be in defining the baseline and over what range of frequencies will it be determined.

Will the baseline be the noise level of post war America and do they have any data from the starting period?

I would prefer to see the FCC enforce Part 15 and other FCC parts that deal with emissions from appliances and other noise sources like Power Transmission systems.

In the latter case, I had to deal with the power company directly in order to mitigate power line noise. Only after threatening them with FCC action, did they finally come out with a spectrum analyzer and admit they did have a problem. I found the offending pole with my MFJ noise detector.

There have been reported EMI from certain makes of furnaces which have electrically noisy controllers. Apparently, no input power filtering was designed in or was never implemented due to cost considerations. Only after a number of hams found this problem did the furnace maker and the FCC get involved.

Then there is the issue of Chinese made goods emitting all kinds of EMI.

Phil - AC0OB

[WD8KDG]

As a casual reply; the amateur radio service (ham radio) is not a large enough political voting population to affect any decision of the FCC/Congress.

Only when Part 15 RFI affects other radio services which are important, have lobbies, affect military, etc will the Noise Floor really become an issue to be fixed.

My ears tell me Part 15 RFI has increase in the last decade.

Craig,

[W5COA]

I think that this would be a very interesting and worthwhile study, and it shouldn't be too difficult to perform. If I were tasked to do this, I would first go to a remote, obviously quiet location during a time when there was little lightning activity. Take a good calibrated receiver and spectrum analyzer and measure the background noise over a wide frequency range. Then go to urban populated areas and take comparative measurements.

Now for my recent experience with noise, I wrote up a summary of what took place.

Radio Noise at Hickory Hills Hideaway
By Jim Wooten W5COA
April, 2016
            I purchased my first tract of land in East Texas back in 1994. It is located in a rural part of Henderson County near the little community of Larue. The property has an elevation of 750 feet above sea level, is about a mile wide and a mile long, and covers 324 acres, most of which are wooded.
            I felt at the time that it would be a very quiet radio location, and I was not disappointed. Although I am not a DX hound, being able to hear very weak signals is a real treat. I have worked stations as far away as New Zealand, which is about half way around the globe.
            For 15 years, I enjoyed the peace and quiet, even though civilization was slowly encroaching. Then, about two years ago, the noise level really started increasing. It sounded like an arc welder, with a raspy buzz. The noise came and went, and I could not tie it to a time of day or day of the week, or correlate it with the weather. I turned off all my electric service, and since the noise continued, I was pretty certain that it was coming in on the power lines. The noise ranged all the way from 0.5 to 150 Mcs. Even 2m FM was severely degraded.
            The noise finally came and stayed, so I called the local electric supplier, Trinity Valley Electric Co-op. They first sent out a crew to visually survey the area, but could not find anything abnormal. The next day, another technician came out with a “machine” that he could use to locate noisy power line elements. I noticed the name “Radar Engineering” on his survey equipment, and knew that they built such gear.
            I invited him into my “radio shack” and let him listen to the noise. I recorded noise levels at 3, 7, 10, 14, and 18 Mcs for reference, and they ranged from S9 to about 10 over. WWV was unreadable at 10 Mcs, so you know the noise was overwhelming. I had my Icom 746 on battery power, so he shut off the power to my shack, and the noise abated on some frequencies, but was still overpowering.
            He then called for the linemen to come assist in disconnecting various sections of the power lines. I stayed in my shack and monitored, and all of a sudden, my receiver went dead. I mean the noise went from S9 to S Zero. I got in my truck and drove to where they were working, and the tech asked if the noise went away. I said yes, and he said that they had disconnected my whole section of the 7KV power line, including the neutral. .
            They found an arcing lightning arrestor, fixed it, and turned my power back on. Now for the interesting part: my noise level went back to about an average of S5. The raspy noise was gone, but now I had significant noise still emanating from the power line. The crew was finished, and I accepted that the noise remaining on the line was probably not preventable without a lot of extra effort. If I could afford the equipment, I would go surveying myself to see if there were other fixable problems in the local area.
            So here is what I have determined: if you want a quiet radio location, you must eliminate overhead power lines. When I built my new barn, I ran the last 500 feet of AC underground. I would have buried more of the power line, but ran out of money in my budget. This makes the new location much quieter, but I do not have the same broadband antenna there, so I cannot yet make an accurate comparison. It will be a chore to move the current antenna.
            In conclusion, I suppose that I will live with the current noise level, at least until I win the lottery and can afford my own power plant. I figure that solar, wind, and diesel should keep a large battery bank charged. I can install a pure sine wave inverter to run the final amplifier. By controlling all my electronics and appliances, I can eliminate any local hash. Also, I need to buy up the remaining land around my station to prevent noisy neighbors from encroaching.
            For a few minutes, I was in Ham Radio Heaven. My life will never be the same after having experienced noise levels at S Zero.
73,
W5COA

Update June 22, 2016:
I have now moved my Icom 746 to the new barn, which is in the middle of my property. The residual noise is much reduced, as I am 500 feet from the nearest overhead power line. When I had my station located in the city, operation was very frustrating due to the noise level. Yes, we are being overwhelmed with unnecessary RF noise, and it would be great if we could begin to reduce this interference.

Jim
 
 

[WD8KDG]

Want a quiet QTH for a radio "listening" station, Greenbank, WV. Been there decades ago........don't forget to check out Cass Railroad, Caanan Valley, & Blackwater.

http://news.nationalgeographic.com/news/2014/10/141010-radio-telescope-green-bank-west-virginia-astronomy/

Regards,
Craig

[W6TOM]

I did RFI complaints for the local power company before I retired last year, in a year I would handle maybe 6 of these complaints, the largest group to complain were hams followed by AM radio RFI complaints. I did this for about 15 years and in many cases it was not the utility company.

Consumer electronics, pulse battery chargers,(Battery Tenders!) motor controls, fluorescent lights,  switching power supplies (many wall warts are switchers) bad cable tv terminations, bad dsl lines and solar to mention a few.

I used a Radar Engineers Model 242 RFI Locator, an outbacker antenna on my vehicle and the handheld antenna. This has been supplanted by the new model 243 since I retired.

The waveform is a capture from an SDR, the source of the pulses is the ham's utility interactive solar electric system. each solar panel has and optimizer Module, I'm told these  will isolate a shadowed panel, the modules are connected to each other by  network cables which is the source of the RFI. It goes away when the sun goes down!!

[W6TOM]

  These are screen captures of a Radar Engineers Model 242 RFI Locator, the person complaining was a ham, he had noise from 80 meters to 6 meters, looked at 40, 20 and 10 meters too. The antenna system was a loop fed through a balanced line antenna tuner.

 The sweep time is 16.6 ms, optimized to see anything with a 60 Hz component.

 The source was a utility interactive solar system in a school across the street. I first saw the RFI when I got near the switch gear by the street, the feed was 12 kv underground. The riser was on a pole in front of the guy's home!! Oddly enough I did not hear it strongly there. There were three large awnings in a parking lot behind the school, each has covered with solar panels and each had it's own conduit, one conduit has this RFI on it. The three panels fed three inverters, one of the inverters was making the RFI.

[wd8das]

I'm really surprised at some of the negative reactions by hams to this effort by a group of engineers and technicians to help the FCC confirm that there is a problem with a growing ambient noise level.   For example, the "eye rolling" and "you've got to be kidding" remarks here by WD8KDG.  Anyone who has had a receiver operating in a urban or suburban location over the course of several years likely has experienced problems of interference from man-made noise and can see the change over the years.  Even people in rural locations suffer from the noise generated by their own consumer electronics!

See one of my professional presentations on this topic...

http://www.wd8das.net/Radio-noise.pdf

It shows an example of how one can approach the problem of measurement - comparing various locations.  It also points out some common offending systems and devices.

Steve WD8DAS

[KD6VXI]

  These are screen captures of a Radar Engineers Model 242 RFI Locator, the person complaining was a ham, he had noise from 80 meters to 6 meters, looked at 40, 20 and 10 meters too. The antenna system was a loop fed through a balanced line antenna tuner.

 The sweep time is 16.6 ms, optimized to see anything with a 60 Hz component.

 The source was a utility interactive solar system in a school across the street. I first saw the RFI when I got near the switch gear by the street, the feed was 12 kv underground. The riser was on a pole in front of the guy's home!! Oddly enough I did not hear it strongly there. There were three large awnings in a parking lot behind the school, each has covered with solar panels and each had it's own conduit, one conduit has this RFI on it. The three panels fed three inverters, one of the inverters was making the RFI.

It would be interesting to know if the offending conduit run was bonded at both ends.

Whiley has boned the NEC so bad this year that it's hard to know what actually will get rolled into next year (we typically follow 3 years behind current NEC,  ie,  today we follow 2014). 

I like the ones who bond the solar inverter run at the service panel  but don't do anything at the inverter side.  Makes a nice choke,  leaving the J center their spewing rf everywhere,  especially at a qtr wave interval of that grounded conduit.

Also a lightening issue.   Los Angeles DWP requires ground bonding at both ends of the conduit now accordingly.

--Shane
KD6VXI

[WD8KDG]

I'm really surprised at some of the negative reactions by hams to this effort by a group of engineers and technicians to help the FCC confirm that there is a problem with a growing ambient noise level.   For example, the "eye rolling" and "you've got to be kidding" remarks here by WD8KDG.  Anyone who has had a receiver operating in a urban or suburban location over the course of several years likely has experienced problems of interference from man-made noise and can see the change over the years.  Even people in rural locations suffer from the noise generated by their own consumer electronics!

See one of my professional presentations on this topic...

http://www.wd8das.net/Radio-noise.pdf

It shows an example of how one can approach the problem of measurement - comparing various locations.  It also points out some common offending systems and devices.

Steve WD8DAS

Steve,

Please go back and re-read all my comments on this subject. A person would have to be deaf not to have noticed the Part 15 RFI.
 

Later.............
Craig

[Steve - K4HX]

True. But actual measurements are needed. No changes will be made on anecdotal presentations. I tend to agree with your comment that amateur radio doesn't have the political clout (read money) to make anything happen, so the measurement may be useless anyway. BUT, since the FCC is asking, it's worth a try (I think).

[WD8KDG]

True. But actual measurements are needed. No changes will be made on anecdotal presentations. I tend to agree with your comment that amateur radio doesn't have the political clout (read money) to make anything happen, so the measurement may be useless anyway. BUT, since the FCC is asking, it's worth a try (I think).

Actual measurements are needed, yes. Long ago while working, I too was required to conduct measurements. All equipment used by me was sent to metrology labs & had those fancy stickers traceable to NIST. Methods used to measure were to industrial standards according to contracts agreed upon by seller & purchaser.

So what is the base line? How quiet was the radio world in 1955? Is it worth a try, yes.

My money says nothing will happen until the RFI  harms other radio services with money & clout. Read: military, government, commercial interests.

Regards,
Craig