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

donate to eham
   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: New to EZNEC - modeling coaxial balun/transformers  (Read 531 times)
N2MG
Administrator

Posts: 10058



« on: November 14, 2017, 09:35:57 AM »

I'd like to know if EZNEC 6 handles coaxial impedance transformers (like a 4:1 used in a typical folded dipole design) - and if so, an example of it (.EZ file)

Thanks
Mike N2MG
Logged
W1VT
Member

Posts: 2529




Ignore
« Reply #1 on: November 16, 2017, 01:11:41 PM »

EZNEC has a transformer model in which you can set one winding to 50 ohms and the other to 200 ohms for a 1:4 impedance transformation.
You can model the balun function by modeling the coax shield as a thick wire and the balun as a load.  Ideally you would measure the choking impedance with a 2 port network analyzer as suggested on the G3TXQ web page.  AFAIK EZNEC can't take a physical model of a balun and calculate the impedance.

Logged
KM1H
Member

Posts: 2666




Ignore
« Reply #2 on: November 16, 2017, 02:11:59 PM »

http://www.hamradiodeals.co.uk/forums/viewforum.php?f=46

http://www.arrl.org/files/file/Antenna%20Modeling%20for%20Beginners%20Supplemental%20Files/EZNEC%20Modeling%20Tutorial%20by%20W8WWV.pdf

Plus there is a lot of files and other Eznec stuff out there if you look.

Carl
Logged
K4SAV
Member

Posts: 2406




Ignore
« Reply #3 on: December 02, 2017, 03:56:29 PM »

There is more than one type of 4 to 1 balun.  Models of ideal current mode baluns are very simple in EZNEC.  The transformers built into the software are implementations of ideal transformers.  

Unun models are easy because one side of the secondary is connected to the shield on the primary side.  Voltage mode baluns are a little more complicated because the shield side of the primary is usually connected to the center tap on the secondary side.  

If you need a more complicated model that can calculate balun loss and common mode currents for a nonideal current mode balun, here is an article by W7EL describing how to do it.
http://eznec.com/misc/ibalun.txt

Jerry, K4SAV
« Last Edit: December 02, 2017, 03:59:42 PM by K4SAV » 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!