SOTA – Lightweight Portable 2m – 70cm Dipole Antenna update

At this link I constructed a 2m lightweight telescopic dipole where the toroid choke is a T37-0 (Tan 0 mix, 50 to 350 Mhz). This version is using a T37-17 (Blue/Yellow 17 mix, 20 to 200 MHz).

In addition to the change of balun core, I made the center insulator 5 mm (~1/4 inch) longer with the aim of creating additional space between the BNC socket and the support pole.

Components:

  • Section of nylon cutting board 55 x 30 mm x 7 mm (2 1/4 inch x 1 1/8 inch x 1/4 inch)
  • 2 * 495 mm (19.5 inch) 6 section telescopic antennas with metric M3 mounting holes
  • BNC panel socket with 3 mm (1/8 inch) holes
  • Balun core T37-17 Blue/Yellow (20 to 200 MHz)
  • Copper wire – 6 bifilar turns of 0.72 mm (21 AWG) winding wire
  • 4 x M3 screws 15 mm long with washers and nuts
  • 3 x solder tabs
T37-17 6 bifilar turns
Portable 2m 145 MHz lightweight dipole components
Lightweight 2m (145 MHz) dipole assembled
Mount the antenna over a telescopic pole or hang it from a convenient support or tree branch
RigExpert VSWR scan centered on 145 MHz, 4 MHz wide

This version has a slightly lower resonant frequency at 145 MHz, perfect for operation on 144.200 SSB and 146.5 FM simplex.

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Last update: 21 July 2019

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