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: 6:1 balun  (Read 3859 times)
CT1FKC
Member

Posts: 7




Ignore
« on: December 29, 2002, 10:56:07 AM »

does anyone have plans for winding a 6:1 balun with toroids. I am planing to use one with a  Windom antenna.
Logged
WB2WIK
Member

Posts: 20595




Ignore
« Reply #1 on: December 30, 2002, 12:50:09 PM »

You didn't say what frequency or power level, but if you use a suitable ferrite material and large enough core to handle the power you run, just wind 5 turns for the secondary and 2 turns for the primary, on the same form, and you have a balun with a 6.25:1 impedance ratio (5/2, squared).  That's close enough, and what most people do, to make a "6:1 balun."

I usually use Teflon-insulated #12 gauge wire and a very large core (2" I.D.) to avoid saturation for KW-level transmitting; for lower power levels, obviously both smaller gauge wire and a smaller core will do.  The wire should be insulated with something (good enamel coating, as a minimum).  I like using stranded-conductor, Teflon-insulated wire because it's very tough and almost impossible to wear through even with long-term vibration.

WB2WIK/6
Logged
CT1FKC
Member

Posts: 7




Ignore
« Reply #2 on: December 31, 2002, 12:22:26 PM »

thank's for the reply.
I am planning to build it for 10 20 and 40m, and for 100w power level.
I presume a T200-2 or FT200-43 work fine for that level.
I'll try it with an antenna analyzer, with a resistive load first to take some conclusions.
73 and Happy New Year.
Logged
AD6JN
Member

Posts: 172




Ignore
« Reply #3 on: January 06, 2003, 03:56:16 PM »

Get a copy of "Building and Using Baluns and Ununs" by J. Sevick.

I recently build a 6:1 (6.24:1) series balun described in chapter 5.  It consists of a 1.56:1 Unun and a 4:1 Balun.  I used 3 toroids F140 mix 61.

1 toroid is for the 1.56 Unun and 2 are for the 4:1 balun.

For 100 watts you can use 20 and 22ga. wire.  The 1.56 unun will be 5 turns quintufilar (20ga. magnetic wire) and the two 4:1 balun coils will be 15 to 17 turns (22ga).  Use TFE on the 4:1 leads with a TFE spacer in the center of the bifilar.  You can use TFE stranded wire and strip some TFE insulation off some wire for the center TFE spacer.  Each coil of the 4:1 must be close to 150 ohms as it is in parallel at the input (75 ohms) and in series at the output (300 ohms).

When testing with the analyzer terminate the balun with a 312 ohm rersistor and plot VSWR versus Log Frequency.  The VSWR should be very flat over the range you defined.

Good luck 73.

Bob AD6JN

 
Logged
N6AJR
Member

Posts: 9908




Ignore
« Reply #4 on: January 16, 2003, 03:33:47 AM »

try http://www.buxcommco.com/  he has a super plan for a windom antenna there and even will sell you the 4 to 1 balun if you need it.. he also has lots of other goodies..tom N6AJR
Logged
CT1FKC
Member

Posts: 7




Ignore
« Reply #5 on: February 01, 2003, 07:36:00 PM »

for what all you have post it seems to me that windom antenna is the best solution for me. not only because it is simple, but also because I can perform some tests with my antenna analyzer about the balun.
and since I am still recovering from a small surgery it will be easy to install.
thank you and good DX.
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!