AN/ARC-5 Handbook

Figure 4-17. Oscillator Check Points 
4--16. FINAL AMPLIFIER.  
(Follow chart below.) 
STEP TEST 
POINT TEST 
EQUIPMENT 
CONTROLS NORMAL INDICATION POSSIBLE 
CAUSES OF 
ABNORMAL 
INDICATION 1.  
 Emission switch to 
CW. Power switch 
to ON. Set 
COUPLING  
control to zero. Set 
the TS-58 switch 
to position 5. 
Press the  
Microphone 
button. (See figure 
4--19.)  TS-58 meter indicates 
l0 (25 ma final PA plate 
current.)  HIGH CURRENT: 
Poor tracking, refer 
to ALIGNMENT 
section, paragraph 
3--5;...

INDUCTANCE 
control for 
maximum PA plate 
current and 
maximum ANT 
current.  to 200 ma final 
PA plate current.)  Steps 1 and 2, but 
not Step 3, relay K-
54 (K-55 also, if 
used) may be 
defective. Sliding 
roller contact on 
ANT TUNING coil 
may be dirty, 
corroded, and not 
making good 
electrical contact.   

4--17. MODULATOR.  
(Follow chart below.)  
 
4--18. PRELIMINARY INSTRUCTIONS: Set up equipment as illustrated in Figure  
 
4--19, with the transmitter and associated equipment connected as in PERFORMANCE section. By 
means of shielded cable, connect from vertical input terminals of scope to indicated TEST POINT. 
Connect output meter across vertical input terminals of the scope. If Weston model 695 output meter 
is used, set it to 0 decibel range. (If Daven model OP-182 is used set the power multiplier...

on OP-182). Press 
microphone  
button and whistle 
loud, sustained  
tone of constant 
pitch into micro  
phone. Measure all voltages 
and make continuity 
measurements. 3. 
  Set emission 
switch to TONE. 
Key  
transmitter.  Antenna current should 
rise to 1.9 amperes. 
Output meter should 
read + 14 db (+ 2 db, 
with 0 db being + 12 
db).  
(OP-182 meter should 
read 700 milliwatts.) Same as above. 
Replace modulator 
tubes with known 
good ones. Check 
for shorted 
capacitors and open 
resistors....

 
Figure 4-19. Modulator Check Diagram