CRX1 Troubleshooting

DC Voltage Readings

These readings were taking with a DC supply voltage of 13.7 VDC, so you may need to scale your expected voltages if you use a different power supply voltage.

Mixer

Q5 Drain: 13.4 V

Q5 Source: 0.16 V

Q5 Gate 1: 0 V

Q5 Gate 2: 0 V

IF Amplifier

Q2 Collector: 13.3 V

Q2 Base: 9.1 V

Q2 Emitter: 8.4 V

Product Detector

Q4 Drain: 13.2 V

Q4 Source: 0.24 V

Q4 Gate 1: 0 V

Q4 Gate 2: 0 V

Audio Amplifier

Q11 Collector/Q12 Base: 9.7 V

Q11 Base: 2.3 V

Q11 Emitter: 1.7 V

Q12 Emitter: 10.3 V

Q12 Collector/Q15 Base: 9.6 V

Q15 Collector/Q16 Collector: 13.5 V

Q15 Emitter/Q16 Base: 9.0 V

Q16 Emitter: 8.3 V

Q17 Emitter: 8.3 V

Q17 Base: 7.7 V

BFO

Q1 Drain: 13.6 V

Q1 Source: 8.8 V

Q1 Gate: 0 V

VXO

Q3 Drain: 13.5 V

Q3 Source: 2.2 V

Q3 Gate: 0 V

Sidetone Oscillator

During keydown

Q13 Collector: ~1 V (may fluctuate on your meter)

Q13 Emitter: 0 V

Q13 Base: 0.6 V