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Old March 23rd 04, 02:28 AM
loopfan
 
Posts: n/a
Default Parallel balun problem with wire loop

Where do I begin?

Let me say that I need help analyzing a dual-balun problem with my short
loop. I have a configuration that is working great, but other than that
it shows that I know next-to-nothing about why it is working ...

I have a short wavelength (about 0.10 wavelength long) wire loop
attached to the balanced port eyelets of a 1:1 voltage balun from W2AU.

I am using twin-lead feedline but get this: the feedline is ALSO
attached to the the balanced port eyelets of the voltage balun. The
unbalanced port with the SO-239 jack is unused and unterminated. THIS
is driving me crazy since it seems to work.

At the end of my feedline I am connected to my tuner's 4:1 internal
voltage balun. (An old Swan/Cubic Tee-type tuner).

I definitely need the loop balun, otherwise my loop becomes a noisy
omnidirectional random wire. This wacky configuration seems to be the
only thing that keeps the whole system balanced, and I don't know why.

(I have also tried using a current balun (W2DU), but it also turns my
short directional loop into a random wire.)

It just plain looks wrong even though it works great. I'd appreciate
some feedback on my funky configuration. Since the antenna covers many
bands with the tuner, I make no attempt at matching the feedline
impedance to the loop, and use a tuner to resonate the whole system.

I've made a web-page about my projects in case you want to look at it
and laugh. My project site has info about my experiences with
coax-loops, but I have since moved on to plain wire loops since they
seem to perform as well or better than the coax-made ones.

htt://www.greertech.com/gpmag/gpmagloop.html

You can find the remote configuration at the bottom of the page.

I just can't explain what's going on here and could use your help. Many
thanks in advance!

73 de LoopFan