[RFI] LED Floodlight warning!!

[Steve Kurtzman]

Not to mention that these do not appear to be UL/CSA listed.  As far as 
I know it is illegal to sell these in Canada.

Run away as fast as you can!

Steve W7SJK
> Date: Sun, 23 Jan 2011 03:46:25 -0800 (PST)
> From: Craig<vk3he at yahoo.com>
> Subject: [RFI] LED Floodlight warning!!
> To: rfi at contesting.com
> Message-ID:<301832.98313.qm at web161206.mail.bf1.yahoo.com>
> Content-Type: text/plain; charset=us-ascii
>
> Hi All
>
> I  recently purchased this   new LED floodlight which has turned into a RFI nightmare. I just want to warn other hams about the huge amount of interference that these lights cause.
>
> My warning might also help those looking for interference sources around their neighborhood. LED floodlights are a disaster as big as bad plasma TV sets because the QRM level is so intense.
>
> These light are becoming popular because they can save you  a lot of money when compared  to running a normal 500 watt floodlight.
>
> I purchased several of these LED lights from various Ebay sellers. They all seem to originate from the same factory. They have   ratings from 10 to 50 watts. These lights are the ones that use a huge  large LED CHIP  rather than discreet individual LEDs
>
> Here is a link for one on Ebay, if it looks like this light avoid it.
>
> http://cgi.ebay.com/Lemansind-50W-White-LED-FloodLight-Wall-WashLight-/270694205505?pt=US_Flashlights&hash=item3f06a1c841
>
> A generic search for "LED floodlight" will show the many seller listings for these lights.
>
>
> These light cause S9+20db hash right across the HF spectrum. Its the worst case of switch mode power supply noise that I have ever encountered. What also amazes me is the strength of this hash that could be detected from a long distance away, upto 1km away!
>
> I emailed the supplier,  and  he  advised me that he has paperwork which certifies the lights with  a C tick compliance. The paperwork is obviously fraudulent or he is just telling lies. Most of the  goods from China have  fake EMC compliance documents and certification ..
>
> When I opened the light, it had a small switch mode power supply module. This module does not appear to have any mains filter or other output filtering. The light is well shielded since the whole assembly is cast  aluminum. The power supply module is well shielded, hence the surprise at the rather high  noise levels.
>
>   I added a IEC filter which did nothing to reduce the noise level. I added 2 X Fair-rite FT240-31 ring cores on the power supply lead and this did not help either. I added 2  X #31  material cores onto the DC output and this did help, however the noise was still shocking.
>
>   I am going to try some capacitor bypassing and perhaps a professional  DC filter. So far the signs are not encouraging. The noise is still very intense. If I dont have luck I will just throw these lights in the bin.
>
> I have these lights in 10 20 and 50 watts and they all have the same interference levels. Its a real shock to turn on my  SDR receiver and see the waterfall go red(5/9+) from 1mhz to 30mhz!
>
> Anyway avoid these lights like the  plague!
>
> 73
> Craig
> VK3HE