Several components don't have values in Glen A. Williamson's schematic.  A good starting point would be:

Cx = 1000 pF low-leakage film Cy = 0.47-2.2 µF Ry = 100 kΩ R1g = 10 kΩ Rt = 10-22 kΩ Rb = 10-22 kΩ 74123 R&C = S&H Timing = 1000 pF and 10 kΩ NE572 Input Res = 20 kΩ NE572 Output Cap = 100-470 pF low-leakage film LF353 Diff. Amp = All 10 kΩ (use external amp for audio gain/headphones) OA-1 Unmark Cap = 10 µF OA-1 Unmark Res = 47 kΩ Gain Control (Fader) = 10 kΩ

(AI Assisted)

Based on a circuit analysis of this microwave transceiver / dual-channel Doppler radar (which pulses a Gunn diode source, samples two receiver phases/frequencies via dual HA-2425 sample-and-holds, and balances/fades the channels using an NE572 compandor/VCA, here is a functional breakdown with recommended component values for the missing labels.

Dual Monostable Pulse Generators (74123)

Function:  Generates short sampling trigger pulses (logic LOW on HA-2425 pin-14 triggers the sample/track mode synchronized to the 555-driven Gunn diode pulse.

The Gunn pulse is 300 µs so the S&H sampling pulse width must be significantly shorter than 300 µs (typically 1 to 10 µs)

For standard 74HC123/74LS123, pulse duration is given by: t ≈ 0.45 * R_ext * C_ext

Set C_ext to 1000 pF.

Set R_ext with a 10k trimpot.

Trim to approximately 0.5 to 5 µs pulses.

Sample-and-Hold Stages (HA-2425)

Function:  Holds the signal during the active transmit/receive microwave return pulse.

Per the HA-2425 datasheet, hold capacitor C_x controls droop rate vs. acquisition time.

A value of 1000 pF provides an acquisition time of provides an acquisition time of approx. 4 µs with low droop rate (polystyrene, polypropylene, or NP0/C0G ceramic or low dielectric absorption).

Compandor / Fader Stage (NE572)

The NE572 variable gain cell input impedance is typically driven via an external resistor that scales the input current: I_in = V_in / R_in

Typical value 20 kΩ for approx 1V peak input signals.

Two variable gain amplifiers (VGAs) acting as complementary gain controls: CH_A + CH_B = 1

Reference divider at V_c to +V and -V.  Sets the control voltage midpoint.  With symmetric supplies, two matched resistors 10 kΩ to +V and 10 kΩ to -V.

NE572 gain control resistors R_t and R_b driven from the fader loop op-amp.  Typical NE572 tracking/bias resistors into pins 2 and 14: 10-22 kΩ

NE572 output filter capacitors (pins 5 and 11 to ground): 100-470 pF

Bottom Loop / Integrator Amp

R1_g = input/reference to ground 10 kΩ

R_y = 100 kΩ (feedback resistor)

C_y = (integrator/averaging cap) 0.47-2.2 µF (sets the slow thermal/AGC fading time constant so the circuit smoothly crossfades between channels without modulating audio/Doppler frequencies).

AC feedback divider (from main output back to integrator): resistor 47 kΩ, capacitor to ground: 10 µF