Transmitter Intermediate Power Amplifier Module A6

c. Capacitors C2 and C3 and inductor

(2) High band. The high-band tuned

L1 prevent rf variations from reaching the

output circuit consists of inductor

-45-volt dc supply. The combination of

T3, trimmer capacitor C8, and

resistors R2 and R3 provides fixed bias,

ganged tuning capacitor C1A. The

and resistor R1 is the emitter swamping

OUTPUT is applied from a tap of

resistor Q1. Inductors L2 and L3 are rf

T3 through S1A and coupling ca-

pacitor C3 in the main frame (fig.

chokes. Capacitor C7 is inserted into the

high-band output tank circuit by S1C to

88) to the grid of V1.

shift the effective range of ganged tuning

C. The combinations of inductor L1 and

capacitor C1B by decreasing the total ca-

capacitor C3, choke rf L2 and capacitor

pacitance. The rf input to module A7 can

C4, and rf choke L3 and capacitor C5 keep

be measured at test jack J2.

rf variations out of the -45-volt dc supply.

d. Inductor L1 and capacitor C5 (in the

Resistor R1 is an emitter swamping re-

main frame (fig. 88) ) form a filter in the

sistor. The combination of resistors R2

-45-volt input to module A7.

and R3 form a voltage divider which sup-

plies base bias for transistor Q1. Capac-

itor C7 is inserted into the high-band out-

18. Transmitter Intermediate Power Amplifier

put tank circuit by S1C to shift the effective

Module A6

range of ganged tuning capacitor C1A by

(fig. 13)

decreasing the total capacitance. The rf

input to module A6 can be measured at

Transmitter intermediate power ampli-

fier module A6 amplifies the rf input from

test jack J2.

transmitter second rf amplifier module

A7 (para 17). The transmitter intermediate

19. Power Amplifier A29

power amplifier module consists of a

(fig. 14)

single intermediate power amplifier, a

Power amplifier A29 is a pentode-type

BAND switch, and a tuned output circuit

for each of the two bands. The output of

rf amplifier stage which, in conjunction

A6 is applied to the grid of tube V1.

with power amplifier (pa) tank module A2

a. The signal from A7 is coupled from

(para 20), develops the required rf power

the top of the center-tapped secondary of

output to the antenna. Plate, screen-grid,

T1 through coupling capacitor C1 to the

and bias voltages for power amplifier tube

emitter of Q1 and from the bottom of the

V1 are supplied by de-to-de converter

secondary of T1 through coupling capac-

module A1 (para 31). The dc filament volt-

itor C2 to the base of Q1. The output at

age is supplied by battery BT1.

the collector of Q1 is coupled through

a. The rf input signal from transmitter

BAND switch S1B to the low-or high-band

ipa A6 (para 18) is applied through par-

tuned output circuit.

asitic suppression network Z1 to the con-

trol grid of V1. The rf signal at the plate

b. Separate tuned output circuits are

of tube V1 is developed across the low-

used for the high and low bands. Switch

or high-band tank circuits located in power

S1 selects the proper circuit when the

amplifier (pa) tank circuit module A2.

BAND switch is positioned.

(1) Low band. The low-band tuned out-

b. A bias voltage of -39.5 volts dc is

applied to the control grid of tube V1

put circuit consists of inductor T2,

through resistor R2, inductor L1, and sup-

trimmer capacitor C6, and ganged

pressor network Z1. Resistor R1 is a

tuning capacitor C1A (fig. 88),

voltage dropping resistor in series with

which is varied by the tuning con-

the -45-input circuit. There is a constant

trols on the front panel to select

voltage drop of approximately 5.5 volts

the desired frequency within the

dc across Zener diode CR1 which is ap-

low band. The output is applied from

plied a fixed grid bias voltage for V1. The

a tap of T2 through S1A and coup-

combination of inductor L1, resistor R2,

ling capacitor C3 in the main frame

and capacitor C1 prevents rf leakage into

(fig. 88) to the grid of V1.