Attic Antenna

[W5LZ]

Darry,
You could probably run it through your garage, or where ever with no significant problems. Changing to coax at some point to continue into/through walls/ceiling/etc is also possible. (Usually done at the end of a run to get into the shack.) It will not contribute to less 'losses' though, it's only for convenience. If you keep that ladder line a reasonable distance from metal, ducting for instance, it shouldn't affect things much.
It's a very good idea to keep things as 'simple' as possible. If you have to change from parallel feed line to coax, then do so. But if you don't have to, then don't. It's also a very good idea to keep that coax section as short as possible, and to use the 'best' coax you can get your hands on, it -will- be affected by the voltage levels. It has very little to do with the power being used, there can be some very large voltage changes involved when changing impedances.
Try running the feed line one way. If it works, fine. If not, then start thinking about how you might change it to make it acceptable.
Not much help, but each and every installation is different and has to be handled accordingly.
- 'Doc

 

[depark]

http://www.worldwidedx.com/amateur-radio-antennas/30736-coil-loaded-dipole-build-photo-diary.html

Hi again, I am about to build a copy of Moleculo's "Coil Loaded Dipole". My last question is about the ladder line. I have no choice but to run the ladder line within 2" of two 8" HVAC ducts. Is there a way of insulating the 450 laddder line from the ducts? Also how do you connect a YA-1 Bencher low pass filter to ladder line? Thanks.

 

[W5LZ]

Darryl,
If you can keep that 2" separation for as short a span as possible, there -may- not be any significant problems with it. If that ladder line is run 'flat' to the ducting, or if it's any significant span twist the thing several times (or maybe several dozen twists), then the 'affect' is sort of equalized between both conductors. There's still some affect present, but maybe not as much. Problems start when one conductor of that ladder line is affected more than the other.
As far as that low-pass filter, I think you're out of luck with that ladder line. You will have to make a transition from coaxial type feed line/connectors to parallel feed line, so why not put that filter before that point? (Before the tuner, if you use one?)
Hope it works for you.
- 'Doc

 

[W5LZ]

Channel Jumper,
"I don't pay no mind to no one that tells me..."
I believe you! Make that drill bit slightly larger than 1 inch, or deform that ladder line pushing it through a 3/4 inch hole... Oops!
- 'Doc