Switching System for Filters

Pictures Click Here

Being an SO2R operator, every time I loose switching antennas, filters manually on the second radio decreases my efficiency and so my score drops down. Therefore I decided to take another step on our station and build a switching system for the ICE Single band filters my dad (CT1CJJ) has for some years (I remember that he saw these filters for the first time on some pics from 1997 VK0IR DXPedition and decided to buy them).

Bellow is described, by steps, how the switching system was built.


Draw schematic of what you planning to build:

Relay Schematic

Automatic and Manual control


Gather the necessary material:

  • Relays - 12VDC 3A
  • Capacitors - 10nF
  • 12V to 5V converter - 78L05
  • Resistance - 1KOhm
  • Diodes - 1N4001
  • Conectors - BNC Panel
  • Conectors - SO239 Panel
  • LEDs - RED 5mm
  • Darlington Array - ULN2004
  • BCD to Decimal converter - HEF4028BE
  • 3 Way ON/OFF Switch
  • 6 Way Rotable Switch
  • Enclosure - Hammod 1441-30


  • Start Mechanical work. (drilling, etc) Thanks dad (CT1CJJ)
  • Start soldering components