12-28-2014, 06:06 PM
[b]
In a word fugetaboutit.
(Ask GNV from Lawn Guyland to provide the etymology.)
I wrote a Key Klix article in Dec 2011 on the subject with a cause summary and some suggested cures. Since you have identified the source, I suggest a case of Coors Silver Bullets and play Lone Ranger during the Super Bowl.
73, Dan
<<I tried to attach the KK article, but it didn't work. So here is the text part "A 21st Century Windmill. Amateur radio operators may be seen as an odd group. Terms like grounding, shielding, and interference are almost unknown to the general public – save discussions of this weekend football games – but are a constant consideration and bane to hams. Hams may often be seen turning appliances on and off, touring the neighborhood with an AM radio or noise sniffer, looking for errant sodium street lamps, or jotting down utility pole numbers; all to reduce their receiver noise level one or two S units. To the observer, it may be like Don Quixote chasing windmills. Behind a few of those windmills, hams often find some true interference sources. Faulty power transformers, leaky cable TV distribution deteriorating street lights, and even some residential switches or appliances that are ready to burst into flames. Hams often work with the source owners to identify, educate and correct the problem. Gee, what a perfect world we live in!
A few years back, a new windmill appeared on the horizon. The Plasma TV hit the market in the 19??s and brought innovations not imagined in a CRT world. Plasma TVs introduced flat screen projection surfaces, large viewing screens (the reported largest is 150 inches), debatably a near perfect and natural video, and a very thin depth profile. Due to the very high cost (over $10K) of these early units; they were mostly restricted to sports arenas, conference venues and similar locations. Recently some Plasma TVs have been appearing in your neighborhood; the home entertainment center, the “man-cave” or the corner sports bar.
So what is this modern interference windmill? Plasma TV units, along with their enhanced video capability, have been documented as a massive interference source. The plasma, a gaseous film is excited by a frequency variable signal causing the photons in the gas to ionize in a variety of spectral pixels. The plasma is sandwiched between two conductive plates; the front plate is transparent and contains a nearly invisible conductive grid. The Plasma TV screen may be visualized as a giant capacitive antenna operating at or near the dielectric breakdown range of voltage and frequency.
There are many, many reports of an RFI buzz from these sets. The digital interference noise is most prominent on the lower bands; 160 is a pure disaster, but all of the HF bands are affected with noise levels reported at S3 to S5 on 40 meters. The reports are especially prevalent in the CW portion of the HF bands. Are brass-pounders more critical or are phonies just more tolerant and deaf? Of course, if the offender is in your own abode, then you have to deal with it. But offensive reports have been noted from Plasma sets in neighboring sets up to a quarter mile away. These friendly neighbors are not likely to be willing to trade-in their monster set, change their viewing times or allow a reflective mesh housing around his multi-$K toy. Manufacturer brand and location do have an impact, at least to some extent. Some enterprising hams have built a Faraday shield around their shack to fend off this ionization intrusion – a big effort not available to all. Some brands seem to be more offensive, while others do a better shielding job.
There is a cohort that claim this consumer interference problem is an anomaly that hams will live through as they have survived assaults before. Logically, there may be some credence to this thought. In the past couple of years, some of the Plasma TV sets coming on the market have a much lower noise pollution factor – maybe a result of a multitude of customer complaints. Availability of competitive or lower cost alternatives, such as LCD and DPL sets, that have lower noise signatures. On the down side, manufacturers claim that Plasma TV units have about a 20 year (10,000+ hours) expected life. How long did all those old B&W sets kick around?
Was that a mumble about Part 15 out there? Don’t count on it! The FCC is either unable or unwilling to effectively police this interference source. In many cases, the manufacturers legally conform to the letter of the Part 15 rules, but can legally circumvent its effective application in the delivered product. Also, most of the end users of this entertainment device really don’t care about your inability to break into that DX pileup.
If a Plasma TV is on your Christmas list, you may want to make a change. If your neighbor is the owner or potential owner, you may be left – at least for the present time – to changing your on-the-air schedule or hope your offending neighbor tosses a beer can through his man-cave screen during the Super Bowl. GD >>
(12-28-2014, 01:53 PM)KC1ACN Wrote: Anyone have any suggestions? ....
In a word fugetaboutit.
(Ask GNV from Lawn Guyland to provide the etymology.)
I wrote a Key Klix article in Dec 2011 on the subject with a cause summary and some suggested cures. Since you have identified the source, I suggest a case of Coors Silver Bullets and play Lone Ranger during the Super Bowl.
73, Dan
<<I tried to attach the KK article, but it didn't work. So here is the text part "A 21st Century Windmill. Amateur radio operators may be seen as an odd group. Terms like grounding, shielding, and interference are almost unknown to the general public – save discussions of this weekend football games – but are a constant consideration and bane to hams. Hams may often be seen turning appliances on and off, touring the neighborhood with an AM radio or noise sniffer, looking for errant sodium street lamps, or jotting down utility pole numbers; all to reduce their receiver noise level one or two S units. To the observer, it may be like Don Quixote chasing windmills. Behind a few of those windmills, hams often find some true interference sources. Faulty power transformers, leaky cable TV distribution deteriorating street lights, and even some residential switches or appliances that are ready to burst into flames. Hams often work with the source owners to identify, educate and correct the problem. Gee, what a perfect world we live in!
A few years back, a new windmill appeared on the horizon. The Plasma TV hit the market in the 19??s and brought innovations not imagined in a CRT world. Plasma TVs introduced flat screen projection surfaces, large viewing screens (the reported largest is 150 inches), debatably a near perfect and natural video, and a very thin depth profile. Due to the very high cost (over $10K) of these early units; they were mostly restricted to sports arenas, conference venues and similar locations. Recently some Plasma TVs have been appearing in your neighborhood; the home entertainment center, the “man-cave” or the corner sports bar.
So what is this modern interference windmill? Plasma TV units, along with their enhanced video capability, have been documented as a massive interference source. The plasma, a gaseous film is excited by a frequency variable signal causing the photons in the gas to ionize in a variety of spectral pixels. The plasma is sandwiched between two conductive plates; the front plate is transparent and contains a nearly invisible conductive grid. The Plasma TV screen may be visualized as a giant capacitive antenna operating at or near the dielectric breakdown range of voltage and frequency.
There are many, many reports of an RFI buzz from these sets. The digital interference noise is most prominent on the lower bands; 160 is a pure disaster, but all of the HF bands are affected with noise levels reported at S3 to S5 on 40 meters. The reports are especially prevalent in the CW portion of the HF bands. Are brass-pounders more critical or are phonies just more tolerant and deaf? Of course, if the offender is in your own abode, then you have to deal with it. But offensive reports have been noted from Plasma sets in neighboring sets up to a quarter mile away. These friendly neighbors are not likely to be willing to trade-in their monster set, change their viewing times or allow a reflective mesh housing around his multi-$K toy. Manufacturer brand and location do have an impact, at least to some extent. Some enterprising hams have built a Faraday shield around their shack to fend off this ionization intrusion – a big effort not available to all. Some brands seem to be more offensive, while others do a better shielding job.
There is a cohort that claim this consumer interference problem is an anomaly that hams will live through as they have survived assaults before. Logically, there may be some credence to this thought. In the past couple of years, some of the Plasma TV sets coming on the market have a much lower noise pollution factor – maybe a result of a multitude of customer complaints. Availability of competitive or lower cost alternatives, such as LCD and DPL sets, that have lower noise signatures. On the down side, manufacturers claim that Plasma TV units have about a 20 year (10,000+ hours) expected life. How long did all those old B&W sets kick around?
Was that a mumble about Part 15 out there? Don’t count on it! The FCC is either unable or unwilling to effectively police this interference source. In many cases, the manufacturers legally conform to the letter of the Part 15 rules, but can legally circumvent its effective application in the delivered product. Also, most of the end users of this entertainment device really don’t care about your inability to break into that DX pileup.
If a Plasma TV is on your Christmas list, you may want to make a change. If your neighbor is the owner or potential owner, you may be left – at least for the present time – to changing your on-the-air schedule or hope your offending neighbor tosses a beer can through his man-cave screen during the Super Bowl. GD >>
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