In my view ( or IMHO ) it would be nice if someone gave a flying... and
would demand that imported electronics would undergo type acceptance and
testing for RFI at a minimum. There is so much stuff sitting RIGHT NOW on
store shelves that is just waiting for someone to take home, plug in, and
drive anyone who has receive signals outside a closed system like cable tv
or the internet, CRAZY. Case in point, LED decorative outdoor landscaping
lighting. Each light fixture has a switching power supply that is
constructed with the cheapest materials, built to no standard, and by the
cheapest labor available. Need I say more. - Mike
-----Original Message-----
From: Dale
Sent: Monday, May 13, 2013 11:47 AM
To: ka5s@earthlink.net ; rfi@contesting.com
Subject: Re: [RFI] Comments on RFI from Ductless Air Conditioning Units?
Cortland,
Thank you for the update on exempted items per Part 15. However, I note the
wording "not cause harmful interference" still applies. That's great, but as
has been noted many times in this forum, the interference happens all too
often. As we all know, when the appliance is owned by anyone other than the
affected op, getting rid of the problem is not easy (and often not
practical).
Sadly, one of the most important truths about RFI suppresion and control is:
contain or eliminate the interference at its source (part of the axiom to
reduce power level of the source). The other truths are increase of
separation distance between source and victim (often not possible) and
improved rejection of the source by the victim (usually not possible or
practical if the victim is an actual antenna, might be possible if the
victim is a cable acting as an antenna).
73, Dale
WA9ENA
-----Original Message-----
From: Cortland Richmond <ka5s@earthlink.net>
Sent: May 13, 2013 8:24 AM
To: rfi@contesting.com
Subject: Re: [RFI] Comments on RFI from Ductless Air Conditioning Units?
it is worth remembering that most appliances are exempted from Part B
(or A) at 15.103, only having to comply with not causing harmful
interference. FCC Knowledge data base I see that new guidance last year
removed exemption Verification (Section 2.902) for: External Thermostats
connected via wire and not contained within the appliance, Exercise
Equipment, Hair Dryers, Heat Guns, Hair straighteners, Electric
Blankets, Paper Shredders, Bed Warmers, and Portable Personal Fan Heaters.
See Publication Number 772105
<https://apps.fcc.gov/oetcf/kdb/forms/FTSSearchResultPage.cfm?switch=P&id=33062>
(3/29/2012) (new).
excerpt: /An exempt appliance is only exempt from equipment
authorization procedures for the functions associated with the digital
device circuitry.*The appliance remains subject to the requirements in
Section 15.5 requiring the device not cause harmful interference, and
Section 15.29 regarding inspection by the Commission.* It is strongly
recommended that manufacturers or importers make every effort to meet
the specific technical standards, follow appropriate FCC equipment
authorization procedures, and comply with quality practices to ensure
all units sold and marketed are, and will remain, compliant. /
(emphasis added)
Cortland
KA5S
On 5/12/2013 2251, Dale wrote:
David,
Be certain to specify FCC Part 15 Class B limits. Those are the limits
applicable to home and office environments.
After that, it will then be up to you to determine if Part 15, Class B
limits are, in fact, adequate for your application. Keep in mind that if
your antennas are fairly close to the shack or house (less than 50 feet
away), you could still have problems with RFI, especially in the HF
range. You probably won't know until you try it.
73, Dale
WA9ENA
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