"Pete Bertini" wrote in news:76qTn.8899
:

Just curious if this has ever been done? I'm thinking about
putting up a 90 foot dipole feed with homemade open wire
line. I'd like to bring it into the shack using paralled runs
of LMR-400 cable, since the final 25 feet is via 3" electrical
conduit that also has rotor and other cables.

I believe the parallel cables with give me a 100 ohm impedance.

Yes, but will the configuration have the benefits you think? See
http://www.vk1od.net/transmissionline/stcm/index.htm for more info.

The open wire will be using #10 with homemade spreaders,
I'm going to try for 600 ohms at the feedpoint. I was wondering

What is 600 ohms, the feed line or the antenna.

If the feed line operates at high VSWR, it doesn't matter a lot what Zo
is. Further, that using tapered lines as a broadband impedance match
requires that the taper section is quite long wrt wavelength.

if tapering the spacing on the feedline would give me a smoother
impedance where the open wire, arrestor, and twin coax arrange-
meet?

I cannot reconcile the 90' dipole and 600 ohms from the little
information you have given.

Your post is very short on information, so it is entirely a guessing
game.

Owen