Travel
Antenna Details
Here are some detailed photos of the travel
antenna coil assembly. All photos are "clickable" to view a larger
image file.
The loading coil is wound on a 5 3/4 inch
length of closet pole wood 1 1/4 inches in diameter. There are 46 turns of #18
stranded wire used on the coil. I placed taps at 14 turns and also 44 turns
from the whip (top) end of the coil. On 20 meters, the coax feed line is clipped
to the coil so that 14 turns are used for loading. For 40 meters, the clip is
used at either 44 or the 46 turn tap.
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The photograph to the left shows
the coil assembly with the whip connection on the top. There are a total
of 46 turns of wire on the coil.
Starting from the top:
- The 20 meter tap is at turn
14. There is a wire soldered to this tap and it is connected to a
solder lug mounted on the bottom of the coil.
- 40 meter tap #1 is at turn 44
- 40 meter tap #2 is at turn 46
- The screw for the ground connection
goes into the wood and makes electrical contact with the 1/4 inch
mounting bolt on the bottom of the coil. The shield of the coax cable
and the counterpoise wires connect to the ground connection.
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The schematic of the antenna is shown
on the left.
The photo on the right shows a close-up
of the bottom of the coil assembly.
- The 20 meter connection from the
tap at turn 14 is at the right.
- 40 meter tap 1 (44 turns) is on
the top.
- 40 meter tap 2 (46 turns) is below
40 meter tap 1.
- The ground connection is at the
bottom and has no wires connected to it. The screw for this solder lug
goes into the wood and makes electrical contact with the 1/4 inch mounting
bolt (with the wing nut).
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