Here in San Diego, our HV problem is just the opposite; that is, the noise is low during the long period of dry weather, then, when we get a foggy night, the moisture collects in the dusty coating on the insulators. I believe that the overhead distribution lines in residential areas are about 12KV (not the final distribution leg, which is two wires, each 120 V above ground and 240 V line-to-line). On a quiet and foggy night, you can hear a sound like frying bacon coming from the pole tops.
The local power company has a crew which cleans the insulators with a blast of distilled water from a truck-mounted nozzle. The power company is more concerned about lost power and fire hazard than RF noise, but the result is lowered RF noise. Ed :-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-) Ed Price [email protected] Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA. USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military & Avionics EMC Services Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis :-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-):-) > -----Original Message----- > From: Barry Ma [SMTP:[email protected]] > Sent: Friday, March 10, 2000 3:24 PM > To: EMC-PSTC > Subject: RE: broad band EM noise > > > The broadband interference from corona and any other high-voltage related > sources indicates the problem of power transmission. Those who detected > and reported it deserve a reward from the power company for helping them > reduce the cost. > > Barry Ma > [email protected] > -------------- > From: <[email protected]>, on 3/10/00 8:14 AM: > > Corona on high voltage insulators is a known source of broadband > interference. Poor connections can also be a problem. A good wash down of > the insulators may temporarily cure or reduce the corona problem. We were > able to locate bad connections near our OATS using a directional antenna > near the power lines. A persistent complaint to the power company may give > the desired results. > > Richard Woods > > > ____________________________________________________________________ > > For the largest MP3 index on the Web, go to http://mp3.altavista.com > > ____________________________________________________________________ > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Jim Bacher: [email protected] > Michael Garretson: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
