[HCARC] Baluns, Ununs, Gamma Match, Stubs

[Kerry Sandstrom]

Bill,

That is an interesting approach.  The way I look at it,  the impedance of 
half a dipole is half of 73 Ohm or about 36 Ohm (same as a quarter wave 
vertical over ground).  If you use a quarter wave of 75 Ohm coax in each 
side of the feed, the impedance at the output of the quarter wave sections 
will be 144 Ohm.  The half wave phasing section in one side will just repeat 
the impedance so it will be 144 Ohm on each side of the T-connector.  The 
T-connector is parallel, so the impedance where you connect the coax 
transmission line to the shack will be 73 Ohm again.  Sounds too good to be 
true!

I'll have to think about how a normal 4:1 balun works with just the half 
wave section of coax.  That is what I used to use on my 16-element colinear. 
It seemed to work OK because I didn't melt the coax feed line with my 300 w 
or so of 2-meter output so it must have been a reasonable match!

Kerry