Figure 21. First and second rf amplifiers (20-70 mc), schematic diagram.

R202, which is bypassed by C232 and C233.

h e a t e r line. The voltage across the plate

Capacitor C234 is the screen grid bypass.

tuned circuit is coupled to the grid of sec-

The rf output voltage in the plate circuit

ond rf amplifier V202 through capacitor -

of V201 is developed across the parallel-

C212.

tuned circuit which consists of tuning in-

b . Second Rf Amplifier V202 (fig. 21).

ductor L201B, capacitor C209, coil L203,

The signal voltage from first rf amplifier

and trimmer capacitor C211. Resistors

V 2 0 1 is amplified by second rf amplifier

R203 and R204 are used to load the plate

V202 and coupled to mixer stage V203A.

t u n e d circuits. Resistor R209 and capac-

The input signal voltage is developed

itor C208 provide decoupling for the plate

a c r o s s grid resistor R205. Cathode bias

c i r c u i t . Bypass capacitor C258 and choke

i s developed by the voltage drop across

L223 are connected in the 6.3-volt bus and

R 2 0 6 , which is bypassed by C238 and

prevent rf currents from circulating in the

C239.

F i g u r e 21. First and second rf amplifiers (20-70 mc), schematic diagram.