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Old March 8th 06, 07:07 AM posted to rec.radio.amateur.antenna
Richard Clark
 
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Default ferrite balun grades

On Wed, 08 Mar 2006 16:16:58 +1300, Mike Newman
wrote:

But how to to determine the effectiveness? Maybe a small bead with a
couple of turns to pick up voltage nodes on the coax feedline, with
and without the choke balun beads.


Hi Mike,

Good start, keep it simple. This presumes you have the material, but
don't know its type (s/b #43 or #64):

Take a short transmission line from your rig;
pass the center conductor through ONE bead;
and bring it back and short it to the shield;
transmit on the 5W range for as long as it takes to read SWR.

You should get a reading of roughly 1.3:1 to 2:1 for the right
material - and - depending on how long you held down the transmit, it
should get toasty warm to blistering hot.

73's,
Richard Clark, KB7QHC