"Howard" wrote in message
...
On Sun, 3 Apr 2005 11:35:15 -0400, "Jack Painter"
wrote:


"garigue" wrote
I just put in a set of under cabinet halogen 20 watters ..... boy what
a
bunch of crap RF wise. There is a 12 V supply that virtually eliminates
the
AM band and somewhat less on HF. This is at distance of 20 plus feet.
Of
course they were made in Hang Chow ... no doubt somewhere east of
Ft.Wayne.

God Bless 73 KI3R Tom Popovic Belle Vernon Pa.

Tom, I have the same awful interference from new under-cabinet halogens.
Similar to your report, mine create terrible interference only through MF,
and limited hash on HF also. Mine are at least 40' away, and the station
power has its own load center/branch panel. The lamps are the switchable
2-level (not variable) and interference is present both settings.

I noticed a brand of halogens at Home Depot (now, of course) that state
"No
Radio interference". Figures.

Jack
Virginia Beach

You have the same disorder I do - the stuff you need comes on the
market after you need it 8-} As to the interference, I'll go out on a
limb and say it's the power supply not the lamp - I've hooked up
halogen lamps directly to 12VDC and had no interference. Wall warts
are, as has been mentioned here many times, notorious for RF
interference.


There are two classes of warts. A simple transformer will convert 120 VAC to
maybe 12 VAC. As long as the transformer core does not go into saturation,
then this wart produces zero EMI. OTOH, a wart that rectifies the AC to DC
has the potential to create considerable EMI. Hams should always consider
the possibility of RF pollution from anything they install in or around
their shack. Variable speed fans, adjustable lighting devices, arc-discharge
lighting, battery chargers, wireless network modems and other personal
electronics all need to be evaluated for their EMI potential. As a ham, you
shouldn't be surprised to find that fluorescent or HID lighting causes RF
noise!!

You can partially protect your shack by always looking for an FCC or CE
compliance marking. Assuming that the devices are legally marked, FCC & CE
marking is a bit of evidence that the product will be limited in RF
emissions. But remember, the standards are based on "average consumer"
conditions, NOT on a special consumer sticking the product in proximity to a
sensitive receiver. As a ham, you place yourself in the position of an
"expert user" of consumer electronic devices; you are no longer a clueless
appliance buyer, but someone who understands RF energy and the vagaries of
its creation and propagation.

You can either accept the responsibility to control EMI in your hobby, or go
back to 11 meters and cable TV.


Ed
WB6WSN