[Elecraft] Local Noise Problem

[Jim McCook]

There is a very serious problem with the local noise source from low 
voltage lighting systems.  These are sold as pendants, single lights, or 
multiple lights on a support, such as a bar.  The retailer supplies them 
with a choice of two types of transformers, either a regular magnetic 
type (non interfering), or an "electronic" supply, which is a very noisy 
switching supply.  The latter is most popular because it's small enough 
to be contained within the smallest fixture. 

I have two neighbors _a block away_ who have incorporated these into a 
remodel project.  These are kitchen overhead lights that create 
paralyzing noise, particularly on 40m.  I sent the manufacturer/model 
number (Kovacs) to W1RFI, who plans testing to measure radiation 
intensity.  Retrofit for such lighting is very expensive, mostly because 
of the mechanical changes involved.  One of those neighbors was also 
causing me a problem with his cheap Chinese laptop supply, which I replaced.

On the ARRL website there is a list of letters sent to consumers by FCC 
indicating a need to correct the noise generated by certain devices; 
several are listed for lighting systems, which undoubtedly are about the 
switching power supplies in low voltage systems.  FCC Part 15, Sections 
15.5 and 18.111 prohibit such interference to a licensed radio station.

If you know a neighbor who plans a remodel or someone who is building a 
house nearby, suggest they select the magnetic transformer.  These 
lights are almost always a part of every remodel project.  This is a 
noise source that could seriously affect our hobby when new construction 
begins en masse again.

73, Jim
W6YA