AN/ARC-5 Handbook

							  
NAVWEPS 16-30ARC5-501 
Handbook 
BENCH TEST 
And 
ALIGNMENT PROCEDURE 
RADIO EQUIPMENT 
AN/ARC-5 
PUBLISHED BY DIRECTION OF THE CHIEF OF THE BUREAU OF NAVAL WEAPONS 
1 October 1949  
						

							 
TABLE OF CONTENTS 
 
 
SECTION I INTRODUCTION  
  1--1. PURPOSE OF BENCH MAINTENANCE PROCEDURE.  
  1--4. DESCRIPTION OF PROCEDURE.  
  1--6. USE OF THE PROCEDURE.  
  1--11. GENERAL DESCRIPTION OF AN/ARC-5 EQUIPMENT.  
  1--14. TEST EQUIPMENT.  
SECTION II PERFORMANCE CHECKS  
  2--1. GENERAL.  
  2--4. RECEIVER CHECKS.  
  2--9. BAND NOISE.  
  2--12. SENSITIVITY.  
  2--15. SELECTIVITY.  
  2--17. AVC CHARACTERISTICS.  
  2--21. TRANSMITTER CHECKS.  
  2--26. TRANSMITTER TRACKING AND LOADING.  
  2--29. MODULATION CHECK.  
SECTION III ALIGNMENT PROCEDURE  
  3--1. RECEIVER ALIGNMENT.  
  3--6. TRANSMITTER ALIGNMENT.  
SECTION IV TROUBLE ISOLATION  
  4--1. RADIO RECEIVER.  
  4--4. AUDIO-FREQUENCY CIRCUIT.  
  4--6. INTERMEDIATE-FREQUENCY CIRCUIT.  
  4--8. CONVERTER CIRCUIT. (Follow chart below).  
  4--10. RADIO-FREQUENCY CIRCUIT.  
  4--11. ANTENNA CIRCUIT.  
  4--12. TRANSMITTER AND MODULATOR.  
  4--15. OSCILLATOR.  
  4--16. FINAL AMPLIFIER.  
  4--17. MODULATOR.   
						

							Figure 1-1. AN/ARC-5 Equipment 
SECTION I INTRODUCTION 
 
1--1. PURPOSE OF BENCH MAINTENANCE PROCEDURE. 
1--2. The basic approach used in the development of this manual has been that of dividing all 
equipments into two categories: 
a. Components operating at or above a minimum standard of satisfactory performance. 
b. Defective or poorly performing components. 
1--3. Bench maintenance is reduced, first, to determining whether or not an equipment is operating 
satisfactorily, and, second, repairing the equipment if it is found to be defective. This division results in 
a procedure having four sections: 
a. INTRODUCTION -- This section presents a brief description of the basic function of the subject 
equipment, its primary power requirements, inter-unit connecting cables, a suggested bench mock-up, 
and other information necessary for quick reference with respect to proper maintenance techniques. 
b. PERFORMANCE CHECKS -- These are of primary importance and are to be performed in 
sequence upon the subject equipment. An equipment that meets all the requirements of this series of 
checks is thereby determined to be satisfactory. An equipment that fails in any one of several of the 
check requirements is assigned, by means of proper references, to the appropriate steps in one or 
both of the two sections described below. 
c. ALIGNMENT -- This section details the steps necessary to return the equipment to a properly 
aligned condition. Practical methods requiring a minimum of maintenance time are employed. 
d. TROUBLE ISOLATION -- This section of the procedure is divided into sections, each of which deals 
with a specific component, stage or stages according to the function of the equipment. When the 
maintenance technician is referred to a section of TROUBLE ISOLATION by the failure of the 
equipment to meet the standards set up in PERFORMANCE, he will find detailed instructions and data 
pertinent to the function. Additional aids in the form of sectional schematics and suggested testing 
techniques are at his fingertips. This eliminates time-consuming manual searching, thus increasing the 
work output and efficiency of the technician. 
 
1--4. DESCRIPTION OF PROCEDURE. 
1--5. The procedure begins with a general description of the appearance, function, and operational 
characteristics of the AN/ARC-5 Communications Equipment. It is followed by a block diagram, list of 
test equipment and tools, and other necessary information. The procedure proper consists of 
PERFORMANCE CHECKS, ALIGNMENT, and TROUBLE ISOLATION sections, each of these 
making use of pictorial diagrams, photographs, and sectional schematics. These aids are related to 
the written material by means of three types of symbols:  
a. A star-encircled letter indicates a MAJOR CHECK POINT, at which satisfactory PERFORMANCE 
can be most easily determined. 
b. An encircled numeral indicates SECONDARY CHECK POINT, at which more detailed circuit 
information such as voltage readings and waveforms, can be obtained for trouble analysis. 
c. C-49 -- Manufacturers circuit symbols, used to cross-reference all diagrams with the written 
material. 
 
1--6. USE OF THE PROCEDURE. 
1--7. The proper procedure to follow in bench maintenance work is that given by the sequence of the 
PERFORMANCE CHECKS. These checks follow an order which will most quickly reveal the proper or 
improper performance of the equipment. 
1--8. The failure of the equipment to meet one of these checks suggests the need for ALIGNMENT, or 
TROUBLE ISOLATION, and appropriate references are made. 
1--9. When the reason for defective operation is found and the defect has been corrected, the 
technician is directed to return to the PERFORMANCE section, repeat the step at which defective 
operation was first noted, and, if PERFORMANCE is satisfactory, to continue with the remainder of the 
PERFORMANCE CHECKS. 
1--10. Satisfactory completion of the last PERFORMANCE CHECK completes the bench maintenance 
for the equipment. 
  
						

							1--11. GENERAL DESCRIPTION OF AN/ARC-5 EQUIPMENT. 
 
1--12. The model AN/ARC-5 Aircraft Radio Communication Equipment (See figure 1--1.) is a multi-
channel radio transmitter and receiver for use on aircraft having a 22 to 30-volt d-c power supply. The 
receivers cover a frequency range of 190 kc to 9.1 mc in five independent units, each unit designed to 
be mounted interchangeably into the receiver racks. Racks are available for either two, and/or three-
unit installations, the receivers operating singly or simultaneously, depending upon requirements. 
Provisions have been made for either local or remote control, but only remote controls are furnished 
with the equipment. The receiver mounting racks will accommodate other rack types of equipment 
such as the AN/ARR-2 Receiver and AN/ARC-5 VHF Transmitter-Receiver. These units will not be 
covered in this procedure. The weight of the equipment, less cables and mechanical linkages, is 23.6 
pounds for a two-receiver installation and 55.2 for a three-receiver installation. 
 
1--13. The receivers are designed for the reception of CW, MCW or VOICE modulation. Manual gain 
control is employed in conjunction with high level automatic gain control. The outputs of each receiver 
may be paralleled on one line to a single headset, or divided for double headset reception by more 
than one operator. A 600-ohm headset is to be used with this equipment. A single antenna is used for 
all receivers and transmitters. The tuning dials are calibrated directly in mc and their accuracy is better 
than 0.5 per cent. The transmitters cover the frequency range of 2.1 to 9.1 mc in five independent 
units. They are designed to be installed in pairs. The transmitter frequency control dial is calibrated in 
megacycles with an accuracy of .03 per cent or better. A crystal calibrator is used in conjunction with 
an electron resonance indicator to spot-check the dial calibrations of each unit. The current drain from 
the d-c power source is 8.8 amperes when transmitting with CW emission, and is reduced to 2.5 
amperes on stand-by. The carrier power output varies between eight watts with VOICE modulation to  
						

							25 watts with CW emission.   
						

							Figure 1-2. Receiver and Transmitter Block Diagrams 
1--14. TEST EQUIPMENT. 
  DESCRIPTION RECOMMENDED 
STANDARD ALTERNATE 1. Bench Test Set AN/GRM-1 AN/ARC-5 TEST BENCH 
HARNESS Stock No. RI6-R-
1047-25 2. Frequency Meter LM-13 LM Series 3. RF Signal 
Generator TS-413/U LP-5 4. Audio Signal 
Generator TS-382A/U HP-200C 5. Output Meter Weston 695 Daven OP-182 6. Voltmeter TS-352/U Simpson 260 7. VTVM TS-375/U RCP 662 or RCA Voltohmyst 
165 8. Oscilloscope TS 239/UP Dumont 241 9. Tube Tester Hickok 547 Hickok 545 or 540  
 
1--15. One additional extension cable will be required for the bench test setup to record modulation 
wave forms in TROUBLE ISOLATION. It should be a two-conductor cable about six inches long 
attached to terminals 10 and 17 of plug 6962 (the plug that fits into modulator receptacle (J-77). The 
other end of the two wire extension cable is terminated in two insulated phone-tip jacks, properly 
identified as terminals I0 and 17 respectively. 
Note 
If the AN/ARC-5/ARR-2A Test Bench Harness, ASO stock No. R16-R-1047-25, is 
used in place of the AN/GRM-1, there will be an individual meter for each of the switch 
positions of the I-104-A and the TS-58/GRM-1. The chart below shows the 
corresponding meter for each of the switch positions on the I-104-A and the TS-
58/GRM-1.  
						

							Figure 1-3. Test Equipment Diagram 
I-104-A 
SWITCH 
POSITION TEST 
UNIT 
#7369 
METERS 
LABELLED CIRCUIT I-104-A 
READING  #7369 
READING 1 INPUT 
VOLTAGE Input voltage from primary 
source. 56 28 V DC 2 INPUT 
CURRENT Total input current from the 
primary source. 14-17 1.4-1.7 A 3 PLATE 
VOLTAGE Plate supply to 12SF7, 12SK7, 
and 12K8 tubes, and screen grid 
voltage on 12A6 tube. 46-50 230-250 V 4 SCREEN 
VOLTAGE Screen grid voltage to 12SF7, 
12SK7 and 12K8 tubes. 38-50 76-100 V 5 CATHODE 
CURRENT Cathode current of R-F amplifier 
and 1st I-F amplifier tubes, type 
12SK7s. 44-60 11-15 ma 6 None Basic movement of meter (50 micro-amperes) direct to-and-
TEST METER binding posts on front panel of I-104-A. I-104-
A. Insert jumper wire between these two posts to protect the 
meter movement. TS-58/GRM-
1 READING #9556 
READING  TS-58/GRM-1 
SWITCH 
POSITION TEST 
UNIT 
#9556 
METERS 
LABELLED CIRCUIT 
TONE CW TONE CW 1 INPUT 
VOLTAGE Input voltage from 
primary source 54 54 27 27 2 SCREEN 
VOLTAGE Screen grid voltage to 
PA tubes 28-31 48-
60 140-
155 240-
300 3 PLATE 
VOLTAGE Plate voltage to final PA 
tubes 51-56 51-
55 510-
550 510-
550 4 OSC. 
PLATE 
CURRENT Plate current of master 
oscillator tube, type 
1626 32-46 32-
46 16-23 16-
23 
ma 5 AMP. 
PLATE 
CURRENT Plate current of final PA 
tubes type 1625 27-40 60-
80 68-
100 150-
200 
ma   
						

							TEST SET COMPONENTS 
TYPE QTY DESIGNATION 
ARMY NAVY USE 1 Antenna A-61-A 
  Phantom antenna (LF, MF, HF 
radio transmitter) 1 ANT. Relay 
Unit BC-442-A RE-2/ARC-5 Antenna relay (LF, MF, HF 
radio transmitter) 1 Control Unit 
  C-29/ARC-5 Transmitter control (or C-
30A/ARC-5) 1   
  C-43/ARC-5 Receiver control 3   MC-237 
  Local tuning crank 1 Cord CD-525 
  DC Outlet to modulator 2  CD-527 
  6-Conductor 1  CD-528 
  5-Conductor 2  CD-531 
  DC Outlet to receiver rack (2-
Conductor) 2  CD-532 
  8-conductor 1  CD-706 
  Receiver Rack adapter (7-
Conductor) 1  CD-905 
  Sidetone test 2  
  CX-31/GRM-1 12-Conductor 1  
  CX-32/GRM-1 18-Conductor 1  
  CX-33/GRM-1 Transmitter rack adapter (7-
Conductor) 6 Diagram 
    Instructions for test equipment 
AN/GRM-1 1 Dynamotor DM-33-A DY-8/ARC-5 Dynamotor (transmitting) 1 Modulator 
  MD-7/ARC-5 Modulator equipped with 
tubes 1 Mounting Base FT-279-A MT-62/ARC-5 Mounting for MT-63/ARC-5 or 
FT-277-A Receiver rack