My last post talked about how some of the LED lights on the market are emitting RF and interfering with different kinds of electronic devices, from TVs to refrigerator control cards to CB radios to hearing aids and more.
I described how the problem is in the power regulation circuit, not the LED solid state device. But I was wrong in the name of the culprit. I indicated it was an SCR, but my technology expert pointed out that the offending part is a "Buck/Boost type IC circuit which is essentially a tuned oscillator containing a coil and capacitor. Oscillators are the fundamental vehicle for achieving RF interference since first illustrated by the inventor of AM radio in the days of the Titanic."
Progress on seeing someone take the lead on this problem has been a disappointment. And then in my searches through the web I found this (to me) startling observation from The Old RF Curmudgeon who said in part:
Yes, the FCC doesn’t give a twiddly-damn about the RF spectrum or its purity. I think that this trend started well over a decade ago, and it is fueled by two deeply-held policy positions within the Commission. First, they badly want to get out of the regulatory enforcement business. They don’t get any major brownie points or funding from Congress for running the Field Enforcement Bureau (or whatever it’s called now), spectrum enforcement is a bottomless pit for them, and it’s a never-ending chore. They would rather auction the spectrum off and tell the happy purchaser, “You look after the cleanliness of *your* bands! We’re outta here!”
The second is the deeply-held regulatory notion that “cellular transmission” with its concurrent frequency re-use is the highest and best use of the spectrum. If you do cellular, you don’t have to worry too much about the ambient noise level as the transmitters are always fairly proximate to the users. The cellular regulatory model is at work not only in public land mobile, but also in private land mobile (where it’s very difficult to get new PLMRS licenses for wide-area mountaintop or major tower stations, and if you do get one about the most station you can then run is “walkie talkie” power levels. And in broadcasting (LPFMs and LPTVs, which also conveniently use up all available channel slots). And in unlicensed consumer Part 15 wireless LANs. “Et cetera, et cetera, et cetera,” as the King of Siam would say.
Don’t know whether you caught it at the time, but a few years ago the Commission floated an NPRM which proposed to *allow* interference sources onto licensed channels (in this case, microwave), using a concept known as the defined “Interference Temperature!” The idea was that “smart radios” in the interference generator source would “know” when the source had gone one bridge too far and would then shut itself down. Lacking that degree of equipment capability by the interferers, the licensee of the channel could always monitor and scream when the measured “interference temperature” rose past established limits.
The industry quickly shot that *^@(&^ idea down!
So, driven by these two philosophical points, the Commission now says, “Please proceed to trash the spectrum with lots of unlicensed low power devices, singing power lines, chirping power meters, high speed digital logic with femtosecond switching times (I exaggerate, but not by much!), screeching LEDs. We don’t care, and we don’t enforce the law here in Dodge City any longer!”
As soon as some clever businessman figures out a use for the 4 degrees Kelvin cosmic microwave background radiation, it too will be quickly licensed and eventually auctioned off.
You and I, being old timers in this art and science, understand the invaluable resource that the RF spectrum represents and we respect it and we do what we can to maintain it in good working shape. The Commission, especially in later years, has been directed and run by lawyers, economists, and politicians who don’t know the physics behind electromagnetic transmission, have none of the “vision thing” for the future non-economic uses for which quiet spectrum could be employed, and consider the spectrum mostly as an exploitable economic good. What would you expect?
Adding to this outrage, there is too much transference of communications today from wired to wireless modes. Most people don’t really need “Web service to the belly-button!” Now my eleven year-old granddaughters are getting their own cell phones. Give me a (&#%$@& break!
Many, many services could be well and cheaply provided by wire, if we just had a broadband Universal Fiber Network in this country. But that’s yet another Commission failure in the “vision thing.” The Asians and perhaps the Europeans will “clean our clocks” on this failure alone.
So, sayonara RF spectrum, my dear old love! I will always remember you as you were in those long-ago days when you were still young, fresh, and beautiful.
I guess I should call off my dogs. It is okay to spread crap around from LED lights according to this philosophy. BUT, I don't like it, and I do not intend to provide an RF transmitter with the LED lights I sell at PrudentRVer.com.
Guess I am from the old school.
sam
