ANSWERS TO QUESTIONS Q1. THROUGH Q40.

A1. Re-creating original modulating frequencies (intelligence) from radio frequencies.
A2. Circuit in which intelligence restoration is achieved.
A3. A circuit that can detect the presence or absence of rf energy.
A4. An antenna, tank circuit for tuning, rectifier for detection, filter to give constant output, and an indicator device.
A5. Heterodyning.
A6. By giving a different beat frequency for each signal.
A7. Regenerative detector.
A8. Oscillator, mixer, and detector.
A9. (1) Sensitive to the type of modulation applied, (2) nonlinear, and (3) provide filtering.
A10. The modulation envelope.
A11. Rectifies the rf pulses in the received signal.
A12. To filter the rf pulses and develop the modulating wave (intelligence) from the modulation envelope.
A13. The current-diode detector is in parallel with the input and load.
A14. When the input voltage variations are too small to give a usable output from a series detector.
A15. Emitter-base junction.
A16. R1.
A17. By the collector current flow through R4.
A18. Emitter-base junction.
A19. A diode detector followed by a stage of audio amplification.
A20. C1 and R1.
A21. Slope detector.
A22. Converting frequency variations of received fm signals to amplitude variations.
A23. A double-tuned tank circuit.
A24. Rectify the rf voltage from the discriminator.
A25. Inductive.

A26. Suppresses amplitude noise without limiter stages.
A27. It helps to maintain a constant circuit voltage to prevent noise fluctuations from interfering with the output.
A28. Limits, detects, and amplifies.
A29. Both grids must be positively biased.
A30. Extreme simplicity, few components, and ease of adjustment.
A31. In the amount and rate of phase shift of the carrier wave.
A32. Because of the incidental frequency shift that is caused while phase-shifting a carrier wave that is similar to fm modulation.
A33. The quadrature grid signal is excited by a reference from the transmitter.
A34. Detecting the presence of rf energy.
A35. Pulse amplitude or pulse duration.
A36. At least 10 times the interpulse period.
A37. By making the time constant for charging the capacitor at least 10 times the maximum received pulse width.
A38. By averaging the value of the pulses over the period of the pulse-repetition rate.
A39. Ppm, pfm, and pcm are converted to either pdm or pam for demodulation.
A40. It will discharge to one-half its value between pulses.