Octopus Tester

Features

• Classic Octopus Tester
  • Design example (N5BL)
• Scope set to X-Y for voltage-vs-current measurement of part
  • Look at scope pattern for device signature
• Out of circuit component tester
  • Useful for matching parts like diodes
• In circuit component tester
  • Test 2 units and compare signatures on scope
• Use 6.3V "filament" transformer
  • 8.91V - Vpeak
  • 17.82V - Vpeak-peak
• 1mA, 10mA "scale" switch
  • Pot adjustments to set current (accommodate transformer and line voltage variances)
• 2 BNC jacks
  • Timebase = XY
  • Connect to XY on scope (X=CH1, Y=CH2)
  • CH2 gets set to INVERT
• Plus, Minus Banana jacks
• AC powered
  • C13 jack with switch
  • 1A Fuse
• Build into Bud Box CU-1945

X-Y Patterns

Resistors

• Resistor - slope line
  • Slope = resistance value
• 1 mA setting = 8901 ohms
• 10 mA setting = 890 ohms

Capacitors

• Oval shape
• 0.3uF, 60 Hz, 8841 ohms
• 3uF, 60 Hz, 884 ohms

• 1 uF caps, 1mA, 10mA selections

Zener

• 3.9V Zener
• 1 mA and 10 mA settings

Schematics

• Adjust RV2/RV2 for total resistance (fixed resistor plus pot)
  • 891 - 1 mA switch setting
  • 8910 - 10mA switch setting

Build

Cutouts on Bud Box CU-1945