The XM240 balun is simply 3 turns around 3 stacked toroids going one way,
then 3 additional turns reversing direction and going the other way. Cable
is no-name rg400/thermax style cable.
Scott
KA1CLX
At 05:31 PM 11/1/98 EST, you wrote:
>
>I'm testing a 2/2 40m stack that uses a Cushcraft 402CD@70' and a XM240@130'.
>I'm feeding this with a WX0B stackmatch. The 402CD is directly coax fed with
>some ferrite beads over the coax , and the XM240 uses the Cushcraft MNXM
>balun.
>
>I'm finding the 2 antennas seperately to be close (within 3-5 dB of each
>other) as expected. What I find that bothers me is that the stack is almost
>always slightly weaker than either of the antennas alone. I wonder if it is a
>phasing problem?
>If so, the bottom antenna would be easier to test phase as I can tell which
>side of the driven element the center/ground of the coax are connected to. I
>need to find out what the phasing is on the MNXM balun for the top antenna so
>I can tell if the bottom is out-of-phase. Does anyone know how this balun is
>wired?
>
>Any ideas/suggestions would be appreciated.
>
>73,
>
>Will
>
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