[Elecraft] Noise from LEDs

[Jim Sheldon]

  I don't usually chime in on these threads, but not all LED's are 
culprits.  I had originally replaced all the incandescent bulbs in my 
house with the compact fluorescent (CFL) type.  My noise floor went up a 
couple of dB when any of them were on, so after a couple of those so 
called "5000 hour" Chinese CFL's actually burned up (yes, smoke, fire 
and flames) I bit the bullet and replaced all the fluorescent lights in 
the house with LED's, including some ceiling fixtures that used 2 and 4 
foot tubes.  Even though I don't have any "light dimmers" in the house, 
I bought the "dimmable" LED 60 and 75 watt equivalents and now my noise 
when they on is exactly the same as when they are all off.  Getting rid 
of the CFL's and doing to the LED's dropped my noise floor to whatever 
the atmospheric (plus whatever the neighbors generate) noise floor is.

Sure glad those CFL's tried to burn down my house as it caused me to get 
rid of them.  I was able to hear and work the South Georgia VP8SGI 
station on 15 meters and he was only maybe S1 here.  Bad propagation to 
that part of the world from Kansas even with 500 watts and a beam so I 
missed the South Sandwich part.  Never heard them except on 30 meters 
and my antenna favors East/West and I swear some of the people that 
worked them on 30 were so strong here that HAD to be using more than the 
legal power limit on 30.

Jim - W0EB
>
>
>
>On Mon, 2016-02-01 at 22:48 -0500, johnpierce wrote:
>>  My kitchen, under cabinet lights, are LEDs.  With those lights turned
>>  on my
>>  noise floor changes from -128db to -102db.  If the circuit is changed
>>  to a
>>  different phase the noise improves by 6db.  All of this at 7mhz and
>>  other
>>  higher bands.  Needless to say the AM broadcast band is highly
>>  affected by
>>  the LEDs.
>>
>>
>>
>>  Placing a type 31 core with three turn of the AC line feeding the LED
>>  power
>>  supply and a clamp on 31 core on the LED side of the power supply
>>  provides
>>  no improvement!  I do not have an oscilloscope to look at the
>>  waveforms.
>>  But given what I have done, why is there no improvement?  I was
>>  following
>>  recommendations provided by NK7Z.
>>
>>


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus