[Towertalk] attenuation of fir trees at 50 mhz and 144

[k0rc]

Good point Chris...

Actually this characteristic is true for decideous trees as well.  During my
432 MHz ATV career I remember seeing a major difference in path attenuation
between summer and winter.  Although we never measured it with test
equipment on one path, a P5 picture in the winter would be a P3 picture in
the summer.  The attenuation became noticable when the sap started running
in the spring.

73 de Bob - K0RC
www.pclink.com/k0rc

----- Original Message -----
From: "Chris BONDE" <ve7hcb@rac.ca>
To: "DanB" <longterm@chatusa.com>
Cc: "tower" <towertalk@contesting.com>
Sent: Saturday, May 18, 2002 12:51 PM
Subject: Re: [Towertalk] attenuation of fir trees at 50 mhz and 144


> At 01:21 PM 2002-05-18 +0000, DanB wrote:
> >Looking for a study on attenuation of fir trees at 50 MHZ and 144.
> >
> >Dan NN7J
> Dan:
> Make sure that you have data for the seasons as well, including wet and
> snow.  I have noticed a lot of difference on attenuation, reflection and
> difraction with the seasons.  We attributed such to the difference on the
> trees, mainly conifers mainly firs.
>
> Try a test if you can measure the known Tx and receved Rx.
>
> Chris opr VE7HCB