Modulator Driver V804 and Transmitter Modulator V804 through V808

Figure 19. Transmitter driver V105 and transmitter power amplifier V106, schematic diagram.

modulator driver. Tubes V805, V806,

the screen grid. Plate voltage is supplied

V807, and V808 perform a dual purpose as

to V803 through plate load resistor R824.

the receiver output amplifier and the

Note. In some rt units, L803 has been substituted

transmitter modulator. On transmit, each

for R850.

stage functions as described in paragraphs

b. The audio output signals developed

43 and 44. However, the plate voltage sup-

across load resistor R824 are coupled

plied to the stages is approximately 300

through C813, potentiometer R843, con-

volts dc on transmit and the drive level is

tacts 1 and 20 of tr relay K802 (energized

increased. Thus, the output power of these

on transmit), contacts 9 and 14 of squelch

stages is higher on transmit than on

relay K801 (deenergized on transmit) to the

receive.

control grid of modulation driver stage

b. The modulated B+ supplied to the

plates of transmitter driver V105 (para

55) and the screen grid and plate of trans-

60. Modulator Driver V804 and Transmitter

mitter power amplifier V106 (para 56) is

Modulator V804 through V808

tapped off the primary winding (terminal

2) of output transformer T802. Jack J803

is a test point for measuring the modulated

a. Tube V804 performs a dual purpose as

B+. The metering circuit connected across

the second receiver audio amplifier and the