Thanks for the reply Scott. I guess what I really need to know is which side
of the driven element is the "hot side" (i.e. goes to the center conductor),
and which is connected to the coax ground. If you looked at the balun with a
DC ohm meter, you should see one side connected to the center of the SO239 and
the other to the ground. If I make the top and bottom antennas so that the hot
side of the coax connects to the same side of the driven element, the phasing
should be correct I believe...
This reminds me of some of the discussions that audio professionals have about
XLR connectors and whether pin 2 or pin 3 should be "hot". I think wars have
been fought over that subject. Basically, in ham radio or audio, the bottom
line is that it doesn't matter which side is which as long as it is consistent
on both ends (or antennas in my case!)
In a message dated 11/1/98 11:02:14 PM GMT Standard Time,
sales@advantagecomm.net writes:
<< 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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