On 8/10/2011 10:07 AM, Craig Funston wrote:
Not sure what to say about the lightning thing. Jan had to be pretty
surprised...

It seems like the newer electronic ballasts cause quite a bit of radio
interference. My first unpleasant encounter was after rebuilding the
panel in my new shop. Late into the night it's time for a radio test &
nothing but static. Couldn't stop it with the squelch, etc. Damn... Was
sure something was wired incorrectly until I tried it the next morning
with the lights off. Bingo! The florescent lights are nice new high
quality with the small energy saver tubes, etc. Biggest change is that
now most florescents use electronic ballasts.

According to some industry publications, the T8 bulbs (the skinny ones)
are more energy efficient than the older T12 design, and some of that
comes from the high frequency (20 kHz to 60 kHz) electronic ballast they
use. The waveform is relatively noisy (20% or so total harmonic
distortion) compared the old style magnetic ballast, and even to the
electronic ballast used in some T12 fixtures.

Ballasts with improved waveforms and more filtering (less than 5% total
harmonic distortion) are available for facilities that need them, but at
a higher cost.

For my situation, it's no longer as interesting to my wife to be able to
hear my every word on the radio now that we're using Spot. If she wants
to talk to me, she'll turn off that set of lights (one wall switch),
reset the squelch, and then transmit.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what
you need to know tinyurl.com/yfs7tnz