HF Antenna Traps V3.0 (sold in packs of two)

Make your single-band antenna into a multibander with our lightweight antenna traps

We like to think that our new HF trap kits are a rather clever design. Their flexible mounting arrangement makes using them so easy!

SOTABEAM traps come in two power levels, 20 Watts and 100 Watts (see our tiny Pico Traps for 10 Watts). Each kit includes two (2) traps.

You decide on the frequency when you build them; recommended range 7 - 25 MHz. Alignment can easily be done using an antenna analyser if you don't have access to other test equipment.

Using Traps

Traps can be used in two ways:

1) By using a trap resonant on the higher frequency that you want your antenna to work on, traps work as an effective isolator. In this application, the trap needs to be resonated in the band. This configuration makes the antenna easy to adjust as the sections do not interact much. In this configuration, our traps show a loss of typically < 0.7 dB.

2) By using a trap resonant between the two bands that you want to use (typically 1 to 2 % percent below the band edge of the higher band), losses are reduced but adjusting the antenna is much more difficult as the two sections interact. In this configuration our traps show a loss of typically < 0.3dB.

We recommend that you resonate your traps at the lowest edge of the band that the trap is to work at. So for a 20m-40m dipole, resonant your trap at 14.0 MHz. This tends to be a reasonable compromise between trap loss and ease of antenna adjustment.

Our traps can be used either way, it's your choice.

This article gives some useful tips on using antenna traps.

W8JI is an authority on all aspects of antenna design - including traps.

What's included in a SOTABEAMS Trap kit?

2 x high quality trap PCBs with plated through holes

4 x 100pF 1kv capacitors (used in series or parallel to give 50pF, 100pF and 200pF options)

2 x mounting hardware for toroids

2 x toroids (T94-6 for 100W and a lighter T68-6 toroid for 20W)

Enamelled copper wire to suit the power level

Downloadable instructions

Testing Traps - video

We recommend our Liquid Electrical Tape for final waterproofing of your traps.

Specification

PCB Length 66mm Width 30 mm

Loss < 0.3 dB

Impedance at resonance typically 20,000 Ohms

Weights per trap: 20 W traps 13g (0.46 oz.), 100 W traps 24g (0.85 oz.)
Weight may decrease due to number of capacitors used and turns of wire.

Other options

For even smaller traps see our Pico Traps