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: Mobile Base Loading vs. Inductive Matching  (Read 307 times)
KB8KRF
Member

Posts: 5




Ignore
« on: July 22, 2007, 09:23:27 AM »

Hello,

I'm attempting to homebrew an HF/VHF/UHF mobile instead of buying one.  I found a halfwave 2m/440 antenna from MFJ for $19 that happens to be 59 1/2" long.  I figured this would be enough to get on HF even if it may not provide stellar performance.  I've read the section in the ARRL Antenna Handbook on mobile antennas several times.  I see how center loading can improve performance over base loading but it doesn't explain how base loading compares to inductive matching alone.

My question is: Does the base loading coil have to be above the ground plane inorder to increase radiation resistance and improve efficiency?  Can't a loading coil placed at the base of the antenna but just inside the vehicle's sheet metal do the same thing?  What if there is 3ft or 4 ft of RG-58 between the base of the antenna and the loading coil?  Will the antenna still perform well?

My preference is to place the loading coil in the trunk along with some switching relays.  This way the coil is in line when Xmitting HF but off line when using the VHF/UHF rig.  Does any one have any experience with a loading coil at this location?

Thanks
John
KB8KRF
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!