Topband: Low band noise

[Brian Miller]

Hi Bruce et al

Radiated noise from a new wind farm eventually forced us to close down and 
exit the ZL6QH contest station. A detailed report on the noise levels is 
available at 
http://www.zl6qh.com/rf-noise-measurements-quartz-hill-2009-v3.pdf .

The ZL6QH wind farm used Siemens 2.3 MW variable speed turbines. We believe 
the noise was generated by the water cooled electronic power converter 
technology that was used to convert the variable output of each turbine to 
the fixed voltage and frequency of the national grid.

Our observations suggested that an HF contest station would have be located 
at least several km from the wind farm to reduce the interference to an 
acceptable level on the low frequency bands.

73

Brian VK3MI ZL1AZE
----------------------------------------------------------------------

Message: 1
Date: Thu, 20 Feb 2014 13:09:51 -0500
From: "Bruce" <k1fz at myfairpoint.net>
To: <topband at contesting.com>
Subject: Topband: Low band noise
Message-ID: <A683AF2F3AEA44CE9BF4F857A9034DDC at k1fzPC>
Content-Type: text/plain; charset="iso-8859-1"

Thank you for those who emailed information. They basically thought the 
larger windmill arrays did not generate much noise. One test, checking all 
bands, was from a mobile K3 with a 9 foot whip antenna.  Unless the whip was 
loaded to 1.8 Mhz it may not pick up much noise at one mile. The most 
probable windmill installation noise source is the inverter.

Smaller home/farm  1 phase  type may give off more wideband noise. Some are 
using transformer-less inverters.

Noise is ever increasing in many areas. There is a need to monitor noise 
sources, and installing more directive receiving antennas.

http://www.solacity.com/connections.htm

Watch the inverter video for more info. Highly informative.
http://www.power-one.com/renewable-energy/products/solar/string-inverters/aurora-uno-single-phase/pvi-30363842-north-america/series