I don't think the ladder line will remain balanced next to that much coax.

I have about 100' 9913 coax running to remote homebrew Balanced-Balanced
(google that) tuner.
Tuner is outside in a plastic tub out in the woods, then feeds 4" open wire
line up a tree to about a 70' dipole up 25'.
Works great, 40 and up.


"Kenneth Scharf" wrote in message
...
Question about using 450 ohm "open wire" twin lead....

My shack is located off the garage toward the front of the house. I can't
run any feed line through the window or walls as these face the front and
sides of the house visible from the street. In order to meet XYL approval
we installed a 1.5" ID plastic electrical pipe in the wall that gives
access to the attic crawlway when we built the add on room.
Right now I have a single RG8/u coax cable running through the pipe in the
attic to my vertical. (The coax leaves the attic via a hole drilled in
the roof under-hang).

I'd like to put up a multi-band dipole feed with open wire line (actually
the 450 ohm web spaced twin lead type). I know that this type of
transmission line should be run in the clear if possible.
I can run it to the attic via the feed pipe, but it will be parallel with
the coax for the 10-15' length of the pipe. I can then run the twin lead
though the attic attached to rafters until I reach a turbine attic vent
and pass the cable out of the roof via a hole drilled in the turbine base.
The hole would be lined with plastic electrical fittings.

Will this scheme work, or will the feed line be too negatively affected by
the surroundings to work with a tuner in the shack? We are not talking
about extreme QRO power, the largest amplifier I have in mind would be
about 350 watts out max, and usually I would run the IC-746 barefoot at
100 watts out.

Ken Scharf, WA2MZE