2 Meter 1/4 Wave Ground
Plane
"RF Launcher"
By Dan, KE7TBB
Here is a very unique and one of a
kind 2 Meter 1/4 wave ground plane project using the base of an
Estes Model rocket launcher as a very portable
support for 2 meter antenna fun. If you're into model rockets
and have an old launcher base just sitting around and want to put it
to work launching rf instead of rockets into the air, then read
on.
The whole idea behind
this project is to utilize that old model rocket launcher that is
"just sitting on the pad" collecting dust, as a frame or
support for a portable 2 meter ground plane antenna. Now it
will be used to "launch" rf instead of rockets!
Parts you will
need:
Estes model rocket launcher no. 302215 (You may use
other brands and models using your own modifications).
Copper
wire. About 57 inches or so depending on your construction
S0-239
connector (optional)
Tape
J B weld
Assorted tools:
soldering iron, solder
Nylon wire ties (Optional)

Start by assembling the launcher.
When completed, remove the metal blast deflect plate and the small
black plastic tube attached to it.
Remove one of the legs.
On the second opening of the leg insert the SO-239 connector.
JB weld or hot glue into place the SO-239 connector leaving room
for the solder joints. Cut exactly 20 centimeters or 8 inches of
wire. Strip and tin both ends of the wire.
Remove the metal
rod from the launcher and solder the wire 2 centimeters or about an
inch from the end of the rod. Insert the rod back on to the legs.
Wrap the wire around the leg with the SO-239 connector. Then
solder the wire to the center of the SO-239 connector.
Now
for the ground plane.
Start by cutting 3, 30 centimeter or foot
long pieces of wire. Strip and tin one end only. Take one of the
wires and cut it 12 centimeters or 5 inches from one end of the
wire. Strip and tin both halves. Solder both ends to the outside of
the SO-239 connector.
Bend the long wire towards the end of the
foot and tape it or use nylon ties onto the foot.
Bend the short wire towards the center of the launcher. Tape it
there but leave the very end of the wire lose.
Solder the other
2 wires to the small wire and tape them down the other 2
legs.
Additional note: Vertical
Radiator attaches to center of SO-239, radials to outer
shell of SO-239.
Tuning: For tuning, shorten or lengthen the
wire feeding the vertical rod or the rod itself as
needed.
Tip: For
ultimate portability do not solder the wire to the rod. Instead
stick the rod and wire in the clamp together, that way you can take
the rod out of the base. Also take the legs off the clamp and fold
them together without breaking the wire. One more thing, the rod can
come apart in 2 pieces if needed for modification.
Dan Nezgoda ~~~ KE7TBB