Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old December 13th 06, 04:07 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 442
Default Angle of radiation


"Jimmie D" wrote in message
...
This afternoon while cleaning a closet I pulled out an old US map that had
been marked with contacts I made back when I worked 10M a lot. After the
local stations there is a big empty area on the map then I started making
contacts again at about 300 miles. Antenna used was a 1/4 lambda

groundplane
with the radials drooping so to match 50 ohms. A chart I found indicates
that this means I have a vertical angle of radiation of 50 to 60 degrees.

Is
this correct??. I didnt think the angle would be so great for this

antenna.

The gap between the farthest of the ground wave contacts and the nearest of
the skip contacts is termed the Skip Zone and the 50 to 60 degree number you
cited sounds accurate. It represents the highest takeoff angle that is
successfully refracted back to earth.

Please note there is no one takeoff angle. It's a range of angles and your
transmissions at many angles are returned simultaneously. A quoted takeoff
angle is merely the angle for the strongest signal. For a given paths a
particular takeoff angle may be optimum, but others will still work.


  #2   Report Post  
Old December 13th 06, 04:51 AM posted to rec.radio.amateur.antenna
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 296
Default Angle of radiation


"Sal M. Onella" wrote in message
...

"Jimmie D" wrote in message
...
This afternoon while cleaning a closet I pulled out an old US map that
had
been marked with contacts I made back when I worked 10M a lot. After the
local stations there is a big empty area on the map then I started making
contacts again at about 300 miles. Antenna used was a 1/4 lambda

groundplane
with the radials drooping so to match 50 ohms. A chart I found indicates
that this means I have a vertical angle of radiation of 50 to 60 degrees.

Is
this correct??. I didnt think the angle would be so great for this

antenna.

The gap between the farthest of the ground wave contacts and the nearest
of
the skip contacts is termed the Skip Zone and the 50 to 60 degree number
you
cited sounds accurate. It represents the highest takeoff angle that is
successfully refracted back to earth.

Please note there is no one takeoff angle. It's a range of angles and
your
transmissions at many angles are returned simultaneously. A quoted
takeoff
angle is merely the angle for the strongest signal. For a given paths a
particular takeoff angle may be optimum, but others will still work.



Makes sense, since as I get further away, 600 miles the density of contacts
actually increases.
Seems to be a really strong concentration of contacts in gulf area from
louisianna on toward
texas from here in north carolina.


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Electromagnetic Radiation N9OGL General 31 March 1st 06 02:42 PM
Electromagnetic Radiation N9OGL Policy 32 March 1st 06 02:42 PM
Angle of Radiation Richard Clark Antenna 67 February 21st 05 09:38 PM
Radiation angle vs turns count in a coil W4JLE Antenna 9 December 20th 04 09:35 PM
Electromagnetic radiation Mike Terry Shortwave 0 August 24th 04 10:23 PM


All times are GMT +1. The time now is 02:59 PM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017