Sparks cause radio frequency interference above
1 GHz

The New Zealand Radio Spectrum Management (RSM) newsletter describes how sparks can cause interference even to services operating above 1GHz.

The article on the NZ Ministry of Economic Development RSM site says:

Hertz proved in 1888 that radio transmissions could be made over a distance by generating a spark.

While this technology was used for communication until replaced by valves in the 1920s, sparks are still common in the equipment we use today - such as cars and welding equipment. As a result, sparks, or arcs, of electrical energy are a common source of radio frequency interference.

An electricity infrastructure company recently reported interference affecting a 51km long 1.8 GHz link at their brand new 220KV Ashburton substation. This South Island link had been sending system fail alarms due to the incoming interference.

Radio Spectrum Management deployed its new high-gain microwave detection system, and tracked the source of the interference to an electric fence surrounding the sub station. This fence contained many lightly corroded twisted wire joints.

Amazingly, the interference was spreading very far up the radio spectrum, as the noise was noted to extend beyond 5 GHz.

Original item at
http://news.business.govt.nz/news/info/rsm/article/9300

Related URL's

NZ Ministry of Economic Development
http://www.med.govt.nz/

NZ Radio Spectrum Managment
http://www.rsm.govt.nz/

New Zealand Association of Radio Transmitters (NZART)
http://www.nzart.org.nz/