[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

HELIX building materials

Hi Guys,

It's me again. I wanted to let everyone know that ACE HARDWARE has some real
good material to build helix antennas. This material is used to cover the 8
foot long flourescent tubes. It has the perfect diameter for 2.401 GHz. It
is very sturdy and light. The diameter is about 1.6 to 1.7 inches.

To built the helix I first cut a strip 1.1 inches out of plastic sheet like
a laser printer transparency. I make this strip about 3 feet long. I wind
the strip around the tube and using a Sharpie, I draw a line on the strip
edge as I unroll the strip. This way I have a guide that is exactly 1.1
inches all around the tube. I then use .250 inch wide copper tape bought
from Neward Electronics to wind it over the line that I have drawn. After
the copper tape covers the whole tube, I use kapton tape or regular
transparent tape to cover the copper tape with about .1 inch of tape on each
side of the copper tape. I then epoxy a 5x5 inch aluminum plate with an SMA
connector to one end and add a piece of copper tape to match it. I get about
1.2 SWR over  an incredible bandwidth of almost 1 GHz. There are some
pictures of the antennas at www.ozoni.com/n4ip I will get the pictures
better organized and post better instructions soon.


Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org