"K8JRM" wrote in message
...
This is an age old question - what is the best way to get 450 Ohm ladder
line
into my shack antenna tuning unit (ATU)? Here is my situation; I have two
4"
PVC tubes inserted into the exterior wall that allow the entrance of
coaxial
cable into my shack. When I run the ladder line into the shack through
one of
these ports, the multi-band wire antenna fed with the ladder line goes
wild! I
can not get the antenna to tune with any of my ATUs.
What about enlarging the hole and covering it with a piece of plexiglas with
two bolts through it, spaced the same distance apart as the gauge of the
ladder line. Connect sections of ladder line to both ends of the bolts --
under the bolt heads on one side and under the nuts on the other.
MFJ makes something along these lines. Please see:
http://mfjenterprises.com/Product.ph...uctid=MFJ-4602
Finally, have you tried tubes of material other than PVC? I ran some
300-ohm TV twinlead through an empty Sue Bee honey squeezer tube and the
pictures were fine. (This was before I owned a signal meter, so I don't
know if it had any bad effect.)
"Sal"