[RFI] The ARRL Contest Update for April 1, 2020

[AA5CT]

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 at 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 at contesting.com> on behalf of AA5CT via RFI <rfi at contesting.com>
Sent: Wednesday, April 1, 2020 2:22 PM
To: Rate Sheet <rate-sheet at arrl.org>; rfi <rfi at contesting.com>; Michael Germino <ad6aa at 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 at 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 at 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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