Installing a Ladder Line to the house
"James barrett" wrote in message
...
I've read some Q&A about ladder line and I didn't see exactly my
question. I want to run 450 ohm ladder line into the house. my tuner
has a built-in balun for a ladder line so I think I can just run the
ladder line all the way to the tuner.
How do I physically attach the ladder line to the house? All I can
think of is to nail it right through the spacers onto the side of the
house. But I don't know if the nails will interfere with transmission
at all.
A second that comes to mind when considering this setup: if I run the
ladder line all the way to the tuner, how do I ground it?
Thanks,
kb1odg
I have thought of running ladder line through the wood above the
basement wall, and accross the joists above a suspended ceiling.
My main concerns a the very high field intesity on the plane of
the transmission line, and the high voltage present when using a
short dipole. For example with 100 W in; a 100 ft dipole, 55 ft
of transmission line on 1.9 MHz shows: 400 V/m (peak) only 6"
from each side of the ladder line, and a peak input voltage of
2.4 kV.
While the above is an extreme example I think some analysis
needs to be done before attempting such an instalation. With
all the satellite coax, and house wiring in the ceiling I wondered
how much TVI I would get. On 40 m I estimate about 8 V/m
(peak) from the antenna (1Kw out) at the TV. It is enough to
get into the remote control circuitry, and turn on the TV menu
blocking out the picture.
73,
Frank
|