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Old November 14th 05, 10:14 PM
james
 
Posts: n/a
Default Building a Base CB Antenna ?

On Sun, 13 Nov 2005 20:44:41 -0600, "The Webbers / Hilltop Cycle"
wrote:

+I would like to build a base antenna to mount outside on my home. I do not
+have a tripod and prefer not to use one unless I have to.
+I will be running a 2950 or an older cobra with a small homebuilt ( true RMS
+50 watt )footwarmer.
+
+Does anyone know of a good cheap homebuilt antenna I could make and get good
+transmit and receive ?
+Thanks,
+Raz
+

********

If you are wanting a rather inexpensive antenna then try an inverted V
antenna. Basically a center fed dipole with the ends lower than the
feed point. Try to keep the apex angle between 90 and 120 degrees and
feed with a balun.

The major drawback of this kind of antenna is that the radiation
pattern is a figure 8 pattern. Max propogation direction is
perpendicular to the plane of the antenna. Will work adequuately for
both horizontal and vertical signals due to the slope of the arms.

IF you have room, you may also consider a phased array of quarter wave
verticals. You can use between two and as many as 10 verticals to
obtain all kinds of different patterns. Disadvantages of this system
is that you must carefully measure and cut phasing lines. Also to make
the system "steerable" you need a relay switching system. They relays
need to be able to handle the power you plan to use.

There are other designs that also work and can be done rather
inexpensively. At CB frequencies, a full wave loop is just at the
extreme of size limitations for simple construction techniques. It
also is not a bad antenna to use.


I suggest that you go to a library or obtain a copy of the Amature
Radio Antenna Handbook. A good starting point.

james