I ran an end fed zep out of my apartment for several years while I was in
school, and it was not more susceptible to RF "in the shack" than any other
antenna I have used. The antenna was 130 feet of thin essentially invisible
wire. I made the open wire feeders using parallel insulated 20g stranded wire
and used 3/4 inch black electrical tape to make the insulators, which kept the
wires separated about an inch. I ran a KW. I don't recall the exact length of
the feeders but they were probably 40 to 50 feet. I ran mostly 80 and 40
meters. The feeders never arced and the antenna was very well behaved. I ran
the antenna out of desperation since it was about all I could get up, but I
wouldn't hesitate to put another up. The key to "RF" in any shack is a very
well defined ground system that is actually very near RF ground potential.
The whole point of the end fed zep is to transform the high impedance at the
end of a half wave antenna to a low impedance at the shack using something
approaching a 1/4 wave feedline. If you design the antenna according to its
intent it will do what you want, without excessive RF in the shack. I have
used a double extended zep as well and it is also a good antenna but no less
"susceptible" to RF in the shack than the end fed zep. The end fed zep uses a
"balanced" feed system. It does not hook to the "unbalanced" terminals of your
wire tuner but the balanced terminals. It is not a random wire type antenna
fed against ground. As such it behaves just like any other open wire fed
system.
W9OY
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|