Topband: Building a 160m inverted L and tie it into existing objects?

Andreas Hofmann Andreas.Hofmann at microsoft.com
Tue May 21 16:35:39 EDT 2013


Hi,

It is time for me to add an antenna for 160m. I got large trees on my property and sloping ground in 270 degrees, which works very well for my high
band yagi. Should also work well for a vertical I hope. I have done some experiments with a 40 quarter wave vertical hanging from a large fir tree and
4 elevated radials. The vertical works pretty well. Now on to 160. Everything is bigger and I am thinking about hooking it into some things I have.

1. I have a zip line for the kids that runs down slope (well a zip line needs a slope), about 5 - 10 degrees. Direction is to EU. It is 210 feet long and made
out of strong 1/4 inch galvanized steel cable. I am wondering if I can hang off the vertical section of the tree the top of the zip line is on, and then hook
the zip line to the coax outer jacket as the first radial. Off course I would have to consider safety here, kids should not be on the zip line when I operate.
I can see the line from the shack window, so that should be ok. I cannot cut the length of the zip line off course. Is it too long?

2. The top of the zip line starts a few feet above a metal roof of a wood shed. Should I tie into the metal roof? Picture here: http://sdrv.ms/13YkcHi

3. About 150 feet away, in a different direction I got a large old metal object (decommissioned water boiler or oil tank) in the woods. Does it make sense
to run an elevated radial and have its end connect to it.

In general, my 40 vertical was tunable by cutting the lengths of the radiator and the elevated radials. With the proposed idea for the 160m L I will not be able
to trim anything except the length of the vertical portion. Is that enough to tune the antenna for say 1835?

Overall, I think I could manage to do 4 elevated radials. I know that is not perfect, but with tying into some of the proposed things should do it if possible...


Thanks
Andy,
KU7T



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