Base Loaded 160m Half-sloper antenna

big coil

Zoom in on taps

I wanted to have a resonant antenna on 160M so this is what I came up with.

Materials

  • 3in PVC tube
  • PVC Caps
  • Mirror Mount Bracket
  • Spring
  • ~66ft of Flex-weave wire
  • 12awg solid copper wire
  • Spade type connectors
  • PVC cement
  • Miscellaneous hardware

Construction is pretty straight forward

  • Drill end caps for 3/8-24 hardware
  • Ring connector on end of wire that was fed through PVC tube for cap.
  • wrap wire around coil form. Every so often place a tap (spade connector). Closely wind wire and wide space taps for big jumps in inductance. Closely tap wire and increase space on winding for small jumps in inductance.
  • finish off wire with ring connector and assemble last end connector.
  • Drill very small “breather” hole in one end cap
  • Put female connectors on a length of wire that will be your jumper.

Notes

  • I used this on the mobile with a small mast and 56in whip for 80m.
  • Sometimes when I’m really motivated I will solder all taps
  • coil is wrapped in tape to keep it from shifting.
  • spacing between wire affects amount of inductance
  • spring on end cap was used to provide some give for wire
  • 1:1 VSWR at 1.9Mhz. 9:1 at both ends of the band
  • If you can find end caps that are squared off and flat instead of rounded you will make things easier on yourself.