Figure 4B.9. The doubly balanced mixer. Components inside the eye sea are in black while external ones are in red. If no color is stated for a component, it is in black. At the very bottom of the diagram the bottom line, goes to pin 14. Pin 14 connects to minus 12 volts, shown in red. A 62 k ohm resistor, in red, connects from ground to pin 5 of the eye sea. Pin 5 connects to the collector and base of Q9. The emitter of Q9 connects to a 500 ohm resistor, and the other end goes to the bottom line. The base and collector of Q9 connect to the bases of Q7 and Q8. The emitters of Q7 and Q8 each go through their own 500 ohm resistors to the bottom line. The collector of Q7 goes to the emitter of Q5. The collector of Q8 goes to the emitter of Q6. The emitter of Q5 also goes to pin 3 of the eye sea and the emitter of Q6 goes to pin 2. A 20 k ohm resistor, in red, connects between pins 2 and 3. The base of Q5 connects to pin 1 while the base of Q6 connects to pin 4. All of the resistors mentioned below are in red. A 22 k ohm resistor connects from pin 1 to a junction point. Another 22 k ohm resistor connects from pin 4 to the junction point. A 4.7 k ohm resistor connects from the junction point to ground. Another 4.7 k ohm resistor connects from the junction point to minus 12 volts. The junction point is set at minus 6 volts. The collector of Q5 connects to the emitters of Q1 and Q2. The collector of Q6 connects to the emitters of Q3 and Q4. Now hang on tight. The bases of Q2 and Q3 are tied together and go to pin 8. The bases of Q1 and Q4 are tied together and go to pin 10. Pins 8 and 10 go through their own 4.7 k ohm resistors, shown in red, to ground. The collectors of Q1 and Q3 go to pin 6. The collectors of Q2 and Q4 go to pin 12. Pins 6 and 12 go through their own 30 k ohm resistors, shown in red, to plus 12 volts. End verbal description.