[TowerTalk] Lemme pick your brains

["Jim White, K4OJ" <k4oj@tampabay.rr.com>]

FCG es Towertalk de K4OJ

I am toying with the idea of building up 4 receive antennas for use on 
10 - 40 meters...

I want make them verticals as I wish to isolate them as much as possible 
from the transmitting antennas used on each of those bands which are 
horizontally polarized yagis.

I am able to install them far away from the transmitting yagis )as well 
as power lines) next to a pasture adjacent to the station.  It has a 
mote with fence posts around the outside of it... the fence posts would 
be mounting points for the verticals.

They will be fed with 75 Ohm CATV hardline, and I have sufficient tubing 
(I think) to make "full sized" verticals for each of these four bands.

Since they are not going to be used for transmitting and only for 
receiving I am wondering about just how complex their design needs be.

If I understand correctly their length is not super critical and I hope 
I can get away without having to "tune" them - just rivet up a bunch of 
tubing and go so to speak... can I use "half of a yagi element" as close 
enough size/model?

What is the easiest way for me to feed these taking into account it is 
75 ohm CATV feedline (will a simple center to the vertical and shield to 
the ground with a connector even be acceptable?)

 - and -

how extensive a ground system should these need?  Again - since I am 
only using these for receive how much real improvement will I see if I 
go hog wild with radials versus a small quantity under each....

ALSO - I am thinking that I will mount these at just above "ground 
level" as opposed to raising them and using elevated radials - would the 
elevated antenna hear any better with its base up say 8 or 10 feet or is 
it not worth pursuing?

Lotsa questions I know, but here in FL the temperature is going to start 
dropping fairly soon and I wanna hit the ground running as far as 
installation of these antennas.

Thanks for your assistance - reply to me in private and I will digest 
and summarize the collective towertalk knowledge base for the group...

Like K2KIR said about maxing ones signal on transmit I am angling to 
maximize my receiving ability (already have the transmit side planned 
out :-) )

73,

Jim, K4OJ


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