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6 Meter 5/8 Wave Vertical
Antenna
By Mike,
G3JVL
Editors
note: This
antenna project and article was originally posted on the UKSMG Web
Site, (The UK 6 Meter Group), in Metric measurements and is presented
here for your enjoyment in U.S measurements. Full credit goes to the
author of the article, MIKE,
G3JVL. Only minor editing changes were made
for clarity of measurements ( Metric conversion to feet and inches)
and wording......N4UJW ___________________________________________________
The G3JVL 6 Meter ground
plane vertical is a compact antenna that is ideal for portable operations.
If needed, it can be disassembled into a very small bundle no longer than
the longest element.
Although a little engineering work is
required, it is well within the abilities of the home workshop and all you
newly licensed amateurs or 6 Meter buffs!
The vertical itself is
constructed out of four overlapping sections of aluminum tube whose sizes
are given in the diagram below. The four tubes are meant to telescope, so
wall thickness should be chosen to achieve this. In practice, 16swg
might be OK but 18swg will easily fit. The lengths can be held in
place by three stainless steel self-tapping screws or hose
clamps.
The vertical is bottom-loaded with a coil wound on an
insulated form (nylon or similar material - it is not too critical at
50MHz). - the form is about 5 inches long with the top 3/4 inch turned so
it can be inserted into the bottom section of the vertical. The loading
coil consists of ten turns of 16swg diameter coated or insulated copper
wire with one end connected to the bottom section of the vertical with a
machine screw and the other end connected to the ground plate. An
adjustable tap at 5-turns is connected to the input PL-259 socket. Tap can
be soldered or permanently attached in place after VSRW adjustment is
final.

Base Details
Below:

The construction of the 6m vertical
antenna: The four ground plane
elements are Constructed from 49.2 inch long, (3/8") diameter
aluminum tube. These are mounted to the base plate by the use of eight
stainless steel machine screws. This arrangement allows easy
disassembly if needed.
The vertical itself is supported by a piece
of 14 inch by 2 inch aluminum plate about 1/8 to 3/16 inch thick bent into
a 90 degree angle on each end forming a... |______|... shape as viewed
from the side and layed down. The bottom section of the vertical is
insulated by a turned piece of nylon or similar tubing. If you do not have
access to a lathe, any other insulating arrangement should suffice so long
as it is robust and can withstand wind loading on the mount.
The
overall length of the vertical is about 13 feet 6 inches including the
loading coil. The top section should be adjusted to set the center
frequency. If the VSWR at resonance is not close to 1:1 then alter the
position of the tap on the loading coil (remember, changing this will
alter the resonance of the antenna!).
Once completed give the whole
assembly several coats of varnish to keep out the
weather.
Editors note: This project and article was
originally posted on the UKSMG Web Site (The UK 6 Meter
Group) page.
Full credit goes to the author of the article, MIKE, G3JVL. You can
see the original metric article here. http://uksmg.org/content/vertical.htm

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