Section IV. THIRD ECHELON ALIGNMENT

Figure 34. Receiver-Transmitter, Radio RT-505/PRC-25, top view, audio and control chassis A27 open.

Note: Third echelon alignment consists of aligning transmitter power amplifierTank module A2, variable

frequency oscillator module A9, and sidestep oscillator module A20.

43. Alignment of Power Amplifier

of one of the receiver-transmitter AUDIO

Tank Module A2

connectors.

e. Adjust A2T1 for a maximum indica-

tion on the ME-26B/U.

a. Set the rf output of the AN/URM-48

f. Set the rf output of the AN/URM-48

for 30.00 mc, modulated 10 kc by a 1,000 -

for 52.95 mc, modulated 10 kc by a 1,000-

cycle-per-second (cps) tone.

cps tone.

b. Connect the RF output lead of the AN/

g. Set the receiver-transmitter tuning

URM-48 to receiver-transmitter ANT jack

controls for 52.95 mc.

J2 .

h. Adjust A2C1 for a maximum indica-

c. Set the BAND switch of the receiver-

tion on the ME-26B/U.

transmitter at 30-52, and the tuning con-

i. Repeat c through h above until no

trols for 30.00 mc.

further increase in the ME-26B/U meter

d. Adjust the ME-26B/U to measure ac

indication can be obtained.

voltage and connect it across pins A and B