Spark Logic

CK722 germanium PNP transistor connection guide

CK722 germanium PNP transistor Plastic and glass, three leads wiring guide with power, signal assignments, and bench checks.

Plastic and glass, three leads

3 contacts Current package

Raytheon · Flexible tinned leads on 0.08-inch centers.

Check leakage with the base at emitter potential

Required

Use a 3 V source and a 10 kΩ collector resistor. Tie the base to the emitter and read the collector voltage against the negative supply.

  • 3 V emitter rail
  • Collector voltage
    • C (1)
    • RL.1
    • Voltmeter positive
  • Ground
    • Source negative
    • RL.2
    • Voltmeter common
RL 10 kΩ between Collector voltage and GroundCollector voltageRL 10 kΩGround

Bench checks

  • The reading across 10 kΩ indicates the off-state collector current in this fixture. Record it before biasing the base.

Raytheon Transistor Applications, CK722 technical information, collector characteristics and cut-off discussion. Supply and resistor are fixture choices.

Connection scenarios

Compare collector voltage with base bias

Switch the 3 V source off and remove the base-to-emitter jumper. Connect the base to ground through 100 kΩ and reapply 3 V.

  • 3 V emitter rail
  • Collector voltage
    • C (1)
    • RL.1
    • Voltmeter positive
  • Ground
    • Source negative
    • RL.2
    • Voltmeter common
    • RB.2
  • Base bias
RL 10 kΩ between Collector voltage and GroundCollector voltageRL 10 kΩGround
RB 100 kΩ between Base bias and GroundBase biasRB 100 kΩGround

Bench checks

  • Collector voltage should rise relative to the first reading. The rise divided by 10 kΩ gives the approximate increase in collector current.
  • Measure the actual base voltage if comparing gain. The base current is that voltage divided by 100 kΩ.

Raytheon Transistor Applications, CK722 technical information, pp. 110–111. The resistor values set a low-current comparison fixture.

Plastic and glass, three leads wiring map

Highlighted contacts are used in the required step or selected circuit. Select a contact to inspect it.

Plastic and glass, three leads
Map read from the red-dot end of the lead row: C (1), B (2), E (3).
Selected pin details

3 · E

Emitter · Bidirectional

Emitter. It is the most positive terminal in the common-emitter fixture.

Raytheon Transistor Applications, CK722 technical information, p. 110

Electrical limits · Pin in the reference

Models and documents

The map covers the plastic-and-glass case with a red collector dot in Raytheon’s technical sheet. Match later metal-case devices to their own physical drawing.

CK722
Raytheon plastic-and-glass package in the technical information sheet.