[RFI] Power line Noise

RFI Services mike at rfiservices.com
Wed Jun 7 19:17:14 EDT 2006

Hi Jim and everyone,
RFI sources vary due to wind, rain, slight humidity and every other type of
weather condition. Humidity can short the gap containing the arc as well as
swell the wood construction causing the hardware to tighten. Also shorting
the gap.
As for corona, corona is highest during moist, humid and wet conditions.
However corona is rarely the cause of an RFI complaint. Example: When
walking down the street a couple blocks from the ocean front you'll hear
noise/ buzzing at every pole. This is due to tracking and corona. If you
monitor the same poles with an RF receiver, you'll notice very little if any
noise. The exception being if there is also a gap type noise source local to
your position. If this is the case, you'll notice the level change as you
get closer or further from the actual source being monitored. If corona was
a big issue for RFI complaints, hams couldn't operate close to transmission
circuits or coastal areas.
During my workshops I demo the effects of corona versus gap sparks. The
level of amazement is as interesting as that of the measurement of voltage
between a pole staple and the ground conductor.
Corona is often the blame but very rarely (less than 1%) the cause of RFI

Remember, as the day progresses so does the sunshine.
Unless you know your RFI is active in the am, tell your power company RFI
Investigator to show up around 11am. 

And thanks Kelly,

RFI Services
Michael C Martin
6469 Old Solomons Island RD
Tracys Landing, MD 20779
mike at rfiservices.com

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