AN/ARC-5 Handbook

3--6. TRANSMITTER ALIGNMENT. 
 
3--7. PRELIMINARY INSTRUCTIONS. 
Bench Setup- Connect transmitter, with outer shield removed, to AN/GRM-1, as shown in figure 1--3. 
Frequency Meter -- LM-13 -- Couple as indicated in Transmitter Alignment Chart, (See figure 3--3.). 
 
3-8. TRANSMITTER ALIGNMENT NOTES. 
 
3--9. Zero-beat should occur at mid-position of E-62. If it is impossible to obtain a zero-beat with E-62, 
C-60 may be unlocked from its normal locked position and adjusted to give a zero-beat with E-62...

T-19 3.1 mc  
T-20 4.1 mc  
T-21 5.4 mc  
T-22 7.1 mc FREQUENCY dial 
for zero-beat and 
note error. To 
correct, adjust 
master oscillator 
inductance. (See 
Transmitter 
Alignment Notes, 
paragraph 3--10.) 5 Repeat Steps 3 and 4 until the final setting of E-62 with to cover in place is at a mid-
position and dial setting at the high and low is accurate. Dial setting should be within 
0.03 per cent of actual frequency as indicated by LM frequency meter. 6 Remove Phantom Antenna 
to align R-F amplifier....

SECTION IV TROUBLE ISOLATION  
Figure 4-1. Typical Communications Receiver, Bottom View  
Figure 4-2. Typical Receiver, Top View Inside, and Bottom View Dynamotor  

4--1. RADIO RECEIVER. 
 
4--2. DYNAMOTOR UNIT.4--3. PRELIMINARY INSTRUCTIONS: All tests on the receiver will be 
performed using the AN/GRM-1 Test Setup, as shown in figure 1--3. 
 
STEP TEST 
POINT TEST 
EQUIPMENT 
CONTROLS NORMAL INDICATION POSSIBLE 
CAUSES OF 
ABNORMAL 
INDICATION 1. A Control switch to 
MCW or CW 
position. Meter 
switch to position 
3. Dynamotor scans; I-
104-A meter indicates 
from 46 to 50 (230 to 
250 volts dc):  Shorted or open 
dynamotor windings; 
defective plugs or 
jacks;...

-6.   
Figure 4-3. Dynamotor Test Points  

Figure 4-4. Audio Frequency Test Points 
4--6. INTERMEDIATE-FREQUENCY CIRCUIT. 
(Follow chart below.)4--7. PRELIMINARY INSTRUCTIONS: Insert a 0.006 ufd capacitor in series with 
the hot lead from the Signal Generator to the receiver. Use a signal modulated 30 per cent at 400 or 
1000 cycles. Connect Signal Generator to indicated TEST POINT. 
 
STEP 
TEST 
POINT TEST EQUIPMENT 
CONTROLS ARC-5 
RECEIVER 
CONTROLS NORMAL  
INDICATION POSSIBLE 
CAUSES OF 
ABNORMAL 
INDICATION 1 D Tune the Signal Generator to...

Same output 
as in Step 1. 
Signal 
Generator 
input as 
follows: 210,000 uv 220,000 uv 130,000 uv 99,000 uv 3 2 Same as in Step 1. Same as in 
Step 1. 
85,000 uv If normal, 
trouble is in 
1st I-F 
stage. If not 
normal, 
trouble is 
probably in 
2nd I-F 
stage. Note 
When a stage is found defective, test the tube in a tube checker and replace with 
good tube if necessary. Conduct routine resistance and voltage measurements to 
locate the defective or faulty component or components within a stage. When...

4--8. CONVERTER CIRCUIT.(Follow chart below). 
 
4--9. PRELIMINARY INSTRUCTIONS: Use a signal 50 per cent modulated at 400 or 1000 cycles. 
Connect R-F Signal Generator between the TEST POINT and chassis. When using the VTVM, the d-c 
probe having several megohms of series isolating resistance inserted at its tip should be used. (See 
figures 4--7 and 4--8.) 
 
STEP 
TEST 
POINT TEST EQUIPMENT 
CONTROLS ARC-5 
RECEIVER 
CONTROLS NORMAL  
INDICATION POSSIBLE 
CAUSES OF 
ABNORMAL 
INDICATION 1 1 Tune the...

4--10. RADIO-FREQUENCY CIRCUIT. 
( Follow chart below). 
STEP 
TEST 
POINT TEST EQUIPMENT 
CONTROLS ARC-5 
RECEIVER 
CONTROLS NORMAL  
INDICATION POSSIBLE 
CAUSES OF 
ABNORMAL 
INDICATION 1 1 Same as Step 1, paragraph 
4--8. Control to 
MCW Loud clear 
tone.     UNIT FREQUENCY FREQUENCY NORMAL 
SENS.     .19-.55 
mc .55 mc .55 mc 50 uv      .52-1.5 
mc 1.5 mc 1.5 mc 80 uv     1.5-3.0 
mc 3.0 mc 3.0 mc 150 uv     3.0-6.0 
mc 6.0 mc 6.0 mc 130 uv     6.0-9.1 
mc 9.1 mc 9.1 mc 100 uv R-F tube or 
circuit....