Figure 30. Tuning unit 3, second if. amplifier V405 and if. step attenuator, schematic diagram.

Figure 30. Tuning unit 3, second if. amplifier V405 and if. step attenuator, schematic diagram.

by C445, decreases the plate volt-

plifier output is coupled direct

from the plate to the primary wind-

age.

(5) Resistor R428 and capacitor C438

ing of if. transformer T404, which

provide decoupling in the first if,

is resonated to 42-mc by parallel-

amplifier plate circuit. Resistor

c o n n e c t e d capacitor C444. Resis-

R 4 3 3 and capacitor C443 provide

tor R431 functions as a loading re-

d e c o u p l i n g in the second if. am-

sistor to lower the Q of the tuned

p l i f i e r plate circuit.

c i r c u i t . The secondary winding of

(6) The first if. amplifier rf output is

T404 has a 50-ohm output im-

pedance to maintain a low standing

coupled to second if. amplifier

wave ratio to output jack J408, the

V405 by C439. The second if. am-