No wonder OFCOM had no further info or speculation; They were dumbfounded
by the phenom. Maybe this is why (in part) modern bulbs above 25W have been
Argon filled (as well as using a compact, coiled element, although coiling also
raises
the local Tungsten wire temperature thereby improving efficiency)?
"Argon gas is used in fluorescent and incandescent light bulbs to stop the
oxygen in the light bulbs from corroding the hot tungsten filament. The use of
argon in light bulbs prevents the evaporation of the tungsten filaments, which
results in increased light bulb life."
de AA5CT Jim
.
.
On Wednesday, April 1, 2020, 1:29:43 PM GMT-5, Hare, Ed W1RFI <w1rfi@arrl.org>
wrote:
https://www.emcrules.com/2017/04/can-incandescent-light-bulbs-cau<https://www.emcrules.com/2017/04/can-incandescent-light-bulbs-cause.html>
se.html<https://www.emcrules.com/2017/04/can-incandescent-light-bulbs-cause.html>
[https://4.bp.blogspot.com/-9VvK7nvAz1o/WN2WAbM_aSI/AAAAAAAAAeU/rDw7H-8XND0O8GI9djPNKX2258v62yJ9ACEw/w1200-h630-p-k-no-nu/vintage-2061732_640.jpg]<https://www.emcrules.com/2017/04/can-incandescent-light-bulbs-cause.html>
Can incandescent light bulbs cause interference? | EMC and Regulatory
Compliance<https://www.emcrules.com/2017/04/can-incandescent-light-bulbs-cause.html>
Recently the European market surveillance authorities (AdCos) on EMC have been
investigating the potential of incandescent light bulbs to cause radio
interference. The investigation began with reports that some incandescent
lights may be the cause of reported interference to FM broadcast reception.
www.emcrules.com
________________________________
From: RFI <rfi-bounces+w1rfi=arrl.org@contesting.com> on behalf of AA5CT via
RFI <rfi@contesting.com>
Sent: Wednesday, April 1, 2020 2:22 PM
To: Rate Sheet <rate-sheet@arrl.org>; rfi <rfi@contesting.com>; Michael Germino
<ad6aa@sbcglobal.net>
Subject: Re: [RFI] The ARRL Contest Update for April 1, 2020
One may, if interested, check the OFCOM website link I posted earlier and
note that picture posted is indeed an incandescent bulb.
I still have questions related to how the device produced EMI in the 119 MHz
range as indicated on the spectrum analyzer display as can be seen on the
same page.
There may have been un-intentional contact between elements within the bulb
AS this "old timey" bulb used a string (versus a coiled element) of (presumed)
Tungsten suspended from multiple 'hangers' or supports inside the bulb. Note
the hangers top and bottom share common placement within glass top and
bottom respectively. The bulb in the pix has a 'stamp' on the base of 240V,
assuming AC operation, the peak voltage on a circuit of that nature reaches
approx 340 V pk.
The question of whether a vacuum or an inert gas (as is used nowadays)
filled the bulb envelope also remains unanswered.
de AA5CT Jim
.
.
On Wednesday, April 1, 2020, 1:06:30 PM GMT-5, Michael Germino
<ad6aa@sbcglobal.net> wrote:
"Vintage" A modern bulb made to look vintage or "steampunk" may not have been
Incandescent. Probably a "steampunk led bulb".
Mike73, AD6AA
Sent from AT&T Yahoo Mail on Android
On Wed, Apr 1, 2020 at 3:44 AM, Rob Atkinson<ranchorobbo@gmail.com> wrote:
Sadly, the qrznow article covered everything except what is really
interesting: the mode by which the seemingly incandescent "vintage"
bulbs radiated RFI.
73
Rob
K5UJ
Vintage light bulbs were the ultimate cause of interference to
aircraft communications in the Glasgow, Scotland airport area, but
finding it made an interesting story on QRZnow.com. Four bulbs were
all it took to be a real problem.
https://qrznow.com/ofcom-engineers-shine-a-light-on-interference-issue/
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