Topband: A few beverage planning questions

Jerry Keller - K3BZ k3bz at arrl.net
Sat Feb 5 10:07:57 EST 2005


I'm spending the winter devoloping a plan for my first attempt at getting on topband in 2005. I've 
been reading ON4UN's book, plus K1ZM's book with the photos of some of you. This topband reflector 
has also been of help... thanks. To start with, I want to try shunt feeding my 45 foot tower, plus 
one or two beverages for receiving. I have a few beverage construction questions that I hope are not 
too basic (numbered for convenience in answering):

(1) I was planning to run 50 ohm coax with the rest of my feedlines, from the shack out 50 feet thru 
underground PVC pipe.... to an Ameritron remote switching unit in a box at my tower base. As these 
are receive only, can I run RG59U from the box to each beverage without "mismatch" degradation? Or 
should I use RG59U the entire distance?

(2)Are the distances from my tower to the feed point for each beverage important? Is there a minimum 
distance I should observe?

(3) Will wire antennas minimum 40 feet above a beverage significantly degrade performance of either?

(4) Is there a minimum distance that I should separate the beverage feedpoints?

(5) How important is it for a beverage to run in a straight line?

(6) I've been reading that beverages perform differently at different heights above the earth, but 
does it matter very much if the height above earth varies along the length of the beverage, say, 
between 6 and 12 feet above earth?

(7) I think I understand about tapering down at the ends to avoid noise from vertical components, 
but what would be a good minimum from the ends to start the taper?

(8) Is insulated wire better or worse than bare?

(9) If I use insulated wire and trees as supports, can I just staple the wire to the trees? Or 
should I use an insulator? If an insulator, is the standoff distance from the tree significant to 
performance?

(10) Aside from durability concerns, will I get better performance from #14 vs #22 wire? Or stranded 
vs solid wire?

(11) I hope to eventually put in several beverages, but will start with 1 or 2.  I'm in eastern PA 
on top of an east/west ridge, so beverages will slope gently downhill towards the north. I'm 
thinking first, a 500' NE/SW for EU. Second one could be 500' NW/SE. After that I don't know, but 
are these two a good way to start out?

Any ideas or suggestions will be appreciated.

73, Jerry K3BZ














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