Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: confused about a ground plane  (Read 455 times)
AI4WX
Member

Posts: 26




Ignore
« on: February 22, 2009, 01:35:47 PM »

i live in an apt on ground level with ppl above me and to the right of me. I want to move my mobile setup to inside so i dont have to go sit in the car to talk. Problem i'm having is 1. ground plane, 2. coax length, and 3. satellite intereference

I wanted to use my larson antennas and mount them outside, but i cant have a tower here, so i'm confused about this ground plane issue. what i cant seem to find is what the formula is to know how much metal needs to be under an antennas for ground plane.

The coax problem is everything i have is rg58A/U. what is the absolute longest piece that can be used and still have some tx power left. my radio puts out 50W and the antennas have small gain. any ideas?

The satellite issue is simple maybe  all my neighbors have direct tv dishes and i'm wondering if i put my antennas near those dishes would there be any issues? are there any known issues concerning 2/6 and 70 cm around those dishes?  thanks in advance
Logged
K7KBN
Member

Posts: 2817




Ignore
« Reply #1 on: February 22, 2009, 05:16:42 PM »

This assumes, first of all, that you're concerned with 2M and 70 cm.

1.  Ground plane should extend at least 1/4 wavelength from the antenna in all directions. For 2M, think of a pizza pan about 40" in diameter with the antenna in the middle.  If it's a magnetic mount antenna, be sure it's a steel pizza pan.

2.  http://www.ocarc.ca/coax.htm .  This is a good coax calculator.  Plug in the type of coax and the other variables, and it will tell you how much loss you'll be looking at.

3.  Might be a problem, might not.  Easiest thing to do is experiment.
Logged

73
Pat K7KBN
CWO4 USNR Ret.
KB1QBZ
Member

Posts: 44




Ignore
« Reply #2 on: February 27, 2009, 10:25:01 AM »

Here's an article on building a ground plane from Hamuniverse

http://www.hamuniverse.com/2metergp.html

There are also a couple of good articles in the Simple and Fun Antennas for Hams book from ARRL.  Check their web site.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!