[TowerTalk] Re: Trees, Mountains, 15 degrees...

[Pat Barthelow]

Hello again Jim,
I am assuming you gave me True azimuths, not magnetic azimuths...
Your more detailed figures detail the vertical angles over the two mountains 
as follows:
Red Mountain:                6.5 deg vertical angle   at 45 degrees azimuth
Walter Mountain             12 deg  vertical angle   at 91 degress azimuth

Certainly the Walker mountain elevation is significant, and Red Mountain 
significant, though less so.
You should download  the free propagation program called W6ELProp  It will 
draw a Beam heading map for your location, for all locations on the globe.  
The parts of the world that are affected by those two directions and points 
in between, are generally Central Africa through South Africa.
Other local elevations can be shot with respect to azimuths, and the 
corresponding world locations can be determined from W6EL prop.  You should 
still be able to work the African Continent, but it will be harder to do 
than if you had a low elevation angle to the horizon.
Remember, just have fun...and if the West has a low horizon, you should be 
able to work the Pacific, Asia, Australia etc with no problem...

73, de Pat aa6eg at hotmail.com

From: "Jim & Velma Woods" <woods at grantspass.com>
To: "Pat Barthelow" <aa6eg at hotmail.com>
Subject: Re: Trees, Mountains, 15 degrees...
Date: Mon, 24 Jan 2005 15:44:50 -0800
Pat, thanks for your reply.

Thanks for the reply.  I just checked my topo map (or is it chart)
and actually there are two mountains nearby.  My elevation is 1080 ft ASL.

1.  Red Mountain is 2410 ft. ASL at the peak and bears 045 degrees.
The peak is ~2.5 miles from my place.

2.  Walker Mountain is 3866 ft. ASL at a bearing of 091 degrees and
is 2.7 miles from my QTH.   Think that Walker Mountain is the larger 
concern.
Most of the trees here have needles year round rather than leaves.
Thanks for your input ... any additional comments are most welcome.
BTW, in the summer months we miss the sunrise from our kitchen
window due to the darn mountain!

73,  Jim W7PUP

----- Original Message ----- From: "Pat Barthelow"
<aa6eg at hotmail.com>
To: <woods at grantspass.com>; <towertalk at contesting.com>
Sent: Monday, January 24, 2005 11:16 AM
Subject: Trees, Mountains, 15 degrees...

SNIP:
Jim Woods Said:
From: "Jim & Velma Woods" <woods at grantspass.com>
Also, a few miles away is a mid-sized mountain which is east of my site.
I used a topo map to determine that the top of the mountain forms
an angle about 15 degrees above the horizon.  Is this high enough to be a
concern?    Thanks for your input.
Jim, W7PUP woods at grantspass.com

Hi Jim,
15 degrees above the horizon is a very large  vertical angle.   I
checked what 15 degrees means at 3 miles and computed an elevation
difference of about 4000 feet, in 3 miles.
Just to check the math, is your mountain to the east,  4000 feet
higher than you are?
If so...it will be a problem for low angle DX signals, as
previously mentioned.
73, de Pat, AA6EG  aa6eg at hotmail.com