[Elecraft] Noise from LEDs

[Dave Cole]

Hi,
Jim is correct, replace it...  I had a neighbor, and I had several
ferrites on it, all with many many turns of cable, and got very little
positive result, replacing it gave me a positive result...  :)  

Those things generate a horrendous amount of RFI, and the power cables
to the lights are nothing but antenna...  Consider how much reduction
you will need to get to your original noise floor.  If you must keep
the PS, then more turns is better.  Replacement is always preferable to
reduction techniques.
-- 
73's, and thanks,
Dave

For software/hardware reviews see:
http://www.nk7z.net

For MixW support see:
https://groups.yahoo.com/neo/groups/mixw/info

For SSTV help see:
http://groups.yahoo.com/neo/groups/MM-SSTV/info



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.
> 
>  
> 
> AD2F,  John
> 
> ______________________________________________________________
> 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