Thanks, Charles. I didn't look all the way to the end, I will admit. We are
running shorthanded in the Lab, so I am doing lots of things quickly.
I did get another report that several Keurigs did cause RFI problems, but none
that have ever been sent to me as a complaint. I have 3 at home, one still
working, that I can do some testing on, as well as the ARR: Lab coffee pot\,
which is now a Keurig.
________________________________
From: Charles Coldwell <coldwell@gmail.com>
Sent: Friday, January 14, 2022 7:56 AM
To: Hare, Ed, W1RFI <w1rfi@arrl.org>
Cc: rfi@contesting.com <rfi@contesting.com>
Subject: Re: [RFI] Mr. Carlson's Lab: coffee maker RFI
If you watch the whole video (spoiler alert!), at the end he kills the RFI by
shunting the AC with some capacitors and increasing the value of a cap coupling
the AC ground with the DC ground on the other side of the SMPS. He mentioned
that he has about three of these coffee machines and only one of them is
misbehaving.
However the troubleshooting is less satisfactory than is usual for Paul
Carlson, VE7ZWZ (he is usually restoring antique radios). Essentially the
problem is (spoiler alert!) in the microcontroller firmware which appears to
have flipped a bit somewhere in the motor control/PWM code path.
On Fri, Jan 14, 2022 at 6:22 AM Hare, Ed, W1RFI
<w1rfi@arrl.org<mailto:w1rfi@arrl.org>> wrote:
This is very interesting. I do note that the unit in question is defective,
with a motor that seems to be running very slowly. This could be the reason
for the RFI problem. ARRL has zero reports of KRFI (Keurig RFI), but I am sure
many a ham has a Keurig. If any of you do experience this problem, send an
email to rfi@arrl.org<mailto:rfi@arrl.org> with the details.
It is worth noting that under FCC rules, this would be classified as an
appliance (used in heating, cooling, cleaning or the preparation of food). As
such, it is categorically exempt from the specific emissions limits that apply
to other unintentional radiators. Appliances are subject only to the
requirement that the operator use them in a way that does not cause harmful
interference.
Ed, W1RFI
________________________________
From: RFI
<rfi-bounces+w1rfi=arrl.org@contesting.com<mailto:arrl.org@contesting.com>> on
behalf of Charles Coldwell <coldwell@gmail.com<mailto:coldwell@gmail.com>>
Sent: Friday, January 14, 2022 1:24 AM
To: rfi@contesting.com<mailto:rfi@contesting.com>
<rfi@contesting.com<mailto:rfi@contesting.com>>
Subject: [RFI] Mr. Carlson's Lab: coffee maker RFI
Pretty interesting
https://youtu.be/f3dGStQuI7c <https://youtu.be/f3dGStQuI7c>
--
Charles M. Coldwell, W1CMC
"Turn on, log in, tune out"
Belmont, Massachusetts, New England (FN42jj)
_______________________________________________
RFI mailing list
RFI@contesting.com<mailto:RFI@contesting.com>
http://lists.contesting.com/mailman/listinfo/rfi
--
Charles M. Coldwell, W1CMC
Belmont, Massachusetts, New England
"Turn on, log in, tune out"
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|