[TowerTalk] Snow and rain attenuation

[Robert Chudek]

Hi Bill,

The rain and snow attenuation seems to always raise this type of question. At the opposite end of the spectrum (440 MHz) where I ran ATV, snow and rain did not have a perceptible influence on the signals either. What did influence the path was foliage. In the winter we could shoot signals through the trees, but in the summer there was severe attenuation. I suspected the issue was the water or sap rising during the growing season.

But that aside, is there a frequency where rain and snow have a significant attenuation due to its presence in the path?

73 de Bob - K0RC


Message: 9
Date: Mon, 31 Oct 2005 11:12:08 -0800 (GMT-08:00)
From: Bill Jackson <k9rz at radiks.net>
Subject: Re: [TowerTalk] Snow and rain attenuation
To: Dan Hearn <dhearn at wwnw.net>, "Towertalk at Contesting.Com"
<towertalk at contesting.com>
Message-ID:
<31955333.1130785928919.JavaMail.root at mswamui-backed.atl.sa.earthlink.net>

Content-Type: text/plain; charset=us-ascii

Dan,

I work with 6 GHz point to point microwave systems at the railroad.  We do not use heated antennas or radomes.  However, I would recommend you install a dish antenna that includes a fiberglass radome.  This will keep ice and snow from forming on the feedhorn and reflective surface of the dish and will actually lower the amount of wind loading from the antenna. 

At 6 GHz, the amount of additional path attenuation due to falling rain/snow in the air at 6 GHz is negligible and should not be a concern.

73 de Bill, K9RZ