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.

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.

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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