On Fri, 6 Aug 2010 11:12:07 -0500, Cycle-24 wrote:
>What do people use out there for 1:1 baluns on their dipole or Yagi
>antennas?
I use exclusively coaxial chokes wound on ferrite cores. See my Choke
Cookbook and the associated discussion in
http://audiosystemsgroup.com/RFI-Ham.pdf
>Is there any real difference between using cores, beads, or air
>wound coaxial baluns?
Yes, there are MAJOR differences. As Steve observes, the choke should be
RESISTIIVE, not inductive, a HIGH VALUE of resistance is needed to handle
high power, and Fair-Rite #31 and #43 core materials are the weapon of
choice.
For applications up to about 500W, a parallel wire (bifilar) choke on a
single #31 core is quite effective, but depending on feedline length and
antenna imbalance, might overheat at max ham power levels.
Again, study specific winding instructions in that tutorial.
73, Jim Brown K9YC
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|