[Elecraft] OT: LED Light Bulbs

Mark Goldberg marklgoldberg at gmail.com
Tue Oct 24 08:43:14 EDT 2017 

Part of the reason they look so yellow is the low CRI, or color rendering
index. Many bulbs lack deep red, so they look yellow even though they meet
the color temperature spec, they do it by having blue and more yellow and
tricking the measurement. Note that the CRI normally used is still not that
representative of the human eye. There is a newer version rarely used
because most bulbs would come out lousy. The human eye is used to black
body radiation, with a specific mix of colors. Even 2700 k can be perceived
as white if it is close to the black body curve.

I have found two bulbs that are in the 2700 to 3000 color temperature range
that look good. There are Cree TW series ones with high CRI, but 80% of
those I bought failed in three years. I did measure them to have low
conducted emissions with a clamp on probe made from a clamp on ferrite bead
and a spectrum analyzer.
More recently, I bought GE reveal LED bulbs that look good, but have not
measured RFI yet. and have no long term reliability info. These are used in
the XYL's craft room and she complained about the yellow looking ones, but
still likes the lower color temperature. These two types of bulbs are very
expensive compared to others.

Here is some light reading:

https://en.m.wikipedia.org/wiki/Color_rendering_index

https://en.m.wikipedia.org/wiki/Black-body_radiation

https://en.m.wikipedia.org/wiki/Light-emitting_diode#White

73,

Mark
W7MLG

On Oct 24, 2017 4:45 AM, "Clay Autery" <KY5G at montac.com> wrote:

> 3000K.... VERY yellow...  I wouldn't be able to see anything.  I look for
> highest possible...  5000K minimum
>
> 73,
> Clay
>
>
> On 10/23/2017 11:36 PM, Dave Cole (NK7Z) wrote:
>
>> Here is the review of these lights...
>>
>> https://www.youtube.com/watch?v=zJWssuCGkC8
>>
>>
>> 73s and thanks,
>> Dave
>> NK7Z
>> http://www.nk7z.net
>>
>> On 10/23/2017 09:35 PM, Dave Cole (NK7Z) wrote:
>>
>>> Currently Dollar Tree has a set of 60W sunbeam LED lights on sale for a
>>> buck each, and they are dead quiet.  I bought 20 of them today, and swapped
>>> out every light in the house.  Lost about half an S unit of noise.
>>>
>>> 73s and thanks,
>>> Dave
>>> NK7Z
>>> http://www.nk7z.net
>>>
>>> On 10/23/2017 05:07 PM, Kevin Stover, AC0H wrote:
>>>
>>>> Maybe I'm just lucky.
>>>> Over the last two years I changed out all the incandescent and CFL
>>>> bulbs in this house save two. They are the two 150W Halogen lights I have
>>>> to illuminate the garage/driveway/deck if someone gets too close to the
>>>> house at night.
>>>>
>>>> No RFI detected on a K3 or a K2.
>>>>
>>>> On 10/21/2017 11:51 AM, Bob McGraw K4TAX wrote:
>>>>
>>>>> One thing observed at our repeater location is that the CFL was quiet
>>>>> until the the transmitter was on the air. It then generated noise.  In a
>>>>> simplex condition it wouldn't be observed. But in a duplex operation or
>>>>> multiple receiver situation it becomes an issue. Replaced by a LED with
>>>>> lessened issues.
>>>>>
>>>>> Bob, K4TAX
>>>>>
>>>>>
>>>>> Sent from my iPhone
>>>>>
>>>>> On Oct 21, 2017, at 11:21 AM, Jim - N4ST <Hamshack at N4ST.com> wrote:
>>>>>>
>>>>>> I have noticed the background noise level growing on the HF bands,
>>>>>> and for me, especially on 18 Mhz.  I need to declare war on RFI and find
>>>>>> out what is causing this.  I did carefully checkout some Walmart "100 W"
>>>>>> LED lights before committing to them and they were fine.
>>>>>>
>>>>>>
>>>>>> _________
>>>>>>
>>>>>> 73,
>>>>>>
>>>>>> Jim - N4ST
>>>>>>
>>>>>> -----Original Message-----
>>>>>> From: elecraft-bounces at mailman.qth.net [mailto:elecraft-bounces at mailm
>>>>>> an.qth.net] On Behalf Of Bob McGraw K4TAX
>>>>>> Sent: Saturday, October 21, 2017 11:32
>>>>>> To: elecraft at mailman.qth.net
>>>>>> Subject: Re: [Elecraft] OT: LED Light Bulbs
>>>>>>
>>>>>> Makes me wonder if at all or how frequently production lots are
>>>>>> evaluated to determine if they are in FCC Part 15 compliance.
>>>>>>
>>>>>> Otherwise, the approach "we evaluated one production lot, deemed it
>>>>>> passed" {a.k.a - I saw it work once, ship it} and then produced a million
>>>>>> or so afterwards including those with some engineering changes and cost
>>>>>> down changes.
>>>>>>
>>>>>> Guess I need to power the radio from the tractor battery and dump the
>>>>>> main breaker in the house to see how much the noise changes.
>>>>>>
>>>>>> 73
>>>>>>
>>>>>> Bob, K4TAX
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 10/21/2017 9:48 AM, w4sc wrote:
>>>>>>
>>>>>> An observation:
>>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>> I too had RFI from LED lights, but the interference was to OTA
>>>>>>> television, Channel 10 (192-198 MHz) DTV.
>>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>> Not all LED bulbs are created equal in this regard, RFI reduction /
>>>>>>> elimination.  The RFI was generated in this case by the SMPS integral to
>>>>>>> the bulb.
>>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>> The offending bulb is Utilitech part # 5DG6 (printed on the bulb) and
>>>>>>> is ‘C  UL  US’ listed, purchased from LOWEs.
>>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>> I have a overhead fixture that was populated with four 800 lumen
>>>>>>> (60w?) bulbs, 2 being Utilitech, and 2 Sylvania OSRAM.
>>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>> By removing the bulbs and observing channel 10 reception, the
>>>>>>> offending bulb was determined to be the Utilitech.
>>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>> I replaced the the the Utilitech bulbs with Sylvania OSRAM, and the
>>>>>>> RFI on channel 10 OTA was eliminated.
>>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>> The Sylvania OSRAM part number used is LED8.5A19/DIM/0/827/G5/RP as
>>>>>>> printed on the box UPC, and were purchased from LOWEs also.
>>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>> NOTE: There may be interference from Sylvania OSRAM bulbs on other
>>>>>>> frequencies.  LED bulbs are required to meet FCC Part 15 FCC, Class B
>>>>>>> regulations.
>>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>> YMMV
>>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>> I have not seen a comprehensive report or article that unveils “good”
>>>>>>> vs “bad” LED bulb manufacturer and part identification as far as RFI
>>>>>>> emissions across the spectrum.
>>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>> Ben W4SC
>>>>>>>
>>>>>>
>>>>>> ______________________________________________________________
>>>>>>>
>>>>>>
>>>>>> Elecraft mailing list
>>>>>>>
>>>>>>
>>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>>>>>
>>>>>>
>>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>>>>
>>>>>>
>>>>>> Post: mailto:Elecraft at mailman.qth.net
>>>>>>>
>>>>>>
>>>>>>
>>>>>>>
>>>>>> This list hosted by: http://www.qsl.net Please help support this
>>>>>>> email
>>>>>>>
>>>>>>
>>>>>> list: http://www.qsl.net/donate.html Message delivered to
>>>>>>>
>>>>>>
>>>>>> rmcgraw at blomand.net
>>>>>>>
>>>>>>
>>>>>>
>>>>>> ______________________________________________________________
>>>>>>
>>>>>> Elecraft mailing list
>>>>>>
>>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>>>>
>>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>>>
>>>>>> Post: mailto:Elecraft at mailman.qth.net
>>>>>>
>>>>>> This list hosted by: http://www.qsl.net
>>>>>>
>>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>>> Message delivered to hamshack at n4st.com
>>>>>>
>>>>> ______________________________________________________________
>>>>> Elecraft mailing list
>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>> Post: mailto:Elecraft at mailman.qth.net
>>>>>
>>>>> This list hosted by: http://www.qsl.net
>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>> Message delivered to kstover at ac0h.net
>>>>>
>>>>>
>>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Elecraft at mailman.qth.net
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>> Message delivered to dave at nk7z.net
>>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to ky5g at montac.com
>>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to marklgoldberg at gmail.com

More information about the Elecraft mailing list