Home > ARC > Communications receiver > AN/ARC-5 Handbook

AN/ARC-5 Handbook

    Download as PDF Print this page Share this page

    Have a look at the manual AN/ARC-5 Handbook online for free. It’s possible to download the document as PDF or print. UserManuals.tech offer 1 ARC manuals and user’s guides for free. Share the user manual or guide on Facebook, Twitter or Google+.

    							*** at 50,000 microvolts input 
     
    2--17. AVC CHARACTERISTICS. 
     
    2--18. LIMITS: 
    10X Normal sensitivity -- 50 to 150 mw. 
    100X Normal sensitivity -- 100 to 200 mw. 
    1000X Normal sensitivity -- 200 mw. 
    10000X Normal sensitivity -- 200 to 400 mw. 
    Note 
    Normal sensitivity is that setting of the signal generator output necessary to produce 
    10 mw receiver output. 
     
    2--19. PRELIMINARY INSTRUCTIONS. Obtain normal sensitivity before starting this check. This 
    check may be omitted on R-23 and R-24 navigation receivers. 
     
    2--20. TEST PROCEDURE. 
    STEP SIGNAL 
    GENERATOR 
    CONNECTIONS OUTPUT INDIC. 
    & 
    CONNECTIONS NORMAL 
    INDIC. POSSIBLE 
    CAUSES OF 
    ABNORMAL 
    INDICATION 1 Same as Steps 1 
    and 2 of 
    SENSITIVITY check.     1. Audio 
    amplification is 
    insufficient. 
    Refer to 
    TROUBLE 
    ISOLATION, 
    Section IV, 
    paragraph 4--4. 2 Increase attenuator 
    setting 1000X the 
    setting at normal 
    sensitivity. Record reading of 
    output meter. 200 mw 
    indicates that 
    the audio level 
    is sufficient for 
    normal 
    operation. 2. Faulty AVC 
    indicated by a 
    decreasing 
    output with 
    increased signal 
    input. 3 Increase attenuator 
    setting 10000X the 
    setting at normal 
    sensitivity. Same as Step 1. 200 to 400 
    mw Refer to 
    TROUBLE 
    ISOLATION, 
    Section IV, 
    paragraph 4--7. 4 Set attenuator to 
    100X the setting at 
    normal sensitivity. Same as Step 1. 100 to 200 
    mw   5 Set attenuator to 
    10X the setting at 
    normal sensitivity. Same as Step 1. 50 to 150 mw 
        
    						
    							2--21. TRANSMITTER CHECKS. 
     
    2--22. POWER SUPPLY. 
     
    2--23. LIMITS: Input voltage 27.5 v dc. 
    Secondary voltage 545 v dc. 
     
    2--24. PRELIMINARY INSTRUCTIONS: Use Test Set, AN/GRM-1, as shown in figure 1--3. Apply d-c  
    power and allow time for the equipment to warm up. Depress the test key when recording all tests. 
     
    2--25. TEST PROCEDURE. 
     
    STEP C-29/ARC-5 
    CONTROL 
    BOX OPERATION TS-
    58/GRM-1 
    READS VOLTMETER 
    VALUES POSSIBLE 
    CAUSES 
    OF 
    ABNORMAL 
    IND. 1 Select 
    transmitter 1 or 
    2 
    corresponding 
    to the rack 
    position of unit. 
    Switch to CW 
    and key 
    transmitter. Dynamotor 
    runs. Note 
    any 
    evidence of 
    overload in 
    the form of 
    excessive 
    noise or 
    heat.     Refer to 
    TROUBLE 
    ISOLATION, 
    Section IV, 
    paragraph 
    4--12. 2 Same. Switch TS-
    58 to 
    Position 1; 
    read heater 
    voltage. 54 
    divisions. 27.5 v 
      3 Same. Switch TS-
    58 to 
    Position 3; 
    read B+. 51-55 
    divisions. 510-550 v 
      4 Switch to 
    VOICE or 
    TONE. Key 
    transmitter. Same. 51-55 
    divisions. 510-550 v 
        
    						
    							2--26. TRANSMITTER TRACKING AND LOADING. 
     
    2--27. LIMIT: Phantom Antenna Plate Current: 
     TS-58/GRM-1, pos. 5 
    Current No load (zero 
    coupling)  10  25 ma Loaded-MCW-VOICE  20-40  50-100 ma Loaded-CW  60-80  150-200 ma  
    Frequency Calibration: 
    Within 0.03% of dial reading at any frequency, except at crystal frequency, where tolerance b 0.05%. 
    **** 
    R-F Power Output:CW emission--2.25 amps minimum (25 watts) 
    VOICE emission--l.61 amps minimum (13 watts) unmod. 
    TONE emission--1.85 amps minimum (17 watts) 
    **** Above -- listed values of current measured on the ARC No. 7777 Phantom Antenna R-F current 
    meter. 
      
    						
    							2--28. TEST PROCEDURE. 
    STEP TRANSMITTER 
    CONTROLS  OPERATION  NORMAL 
    INDICATION  ABNORMAL 
    INDICATION  1 Select and 
    switch on 
    transmitter 1 or 
    2 depending on 
    position in rack. 
    Switch to CW. 
    Unlock all 
    transmitter 
    controls. Set 
    COUPLING 
    and ANT. 
    INDUCTANCE 
    at zero. Set TS-58/GRM-
    I switch to 
    position 5. Set 
    transmitter dial 
    to the lowest 
    frequency. 
    Observe TS-58 
    GRM-1 meter 
    while tuning 
    transmitter dial 
    throughout its 
    range. TS-58/GRM-1 
    meter reading 
    should not exceed 
    10 through out the 
    range of the 
    tranmitter 
    FREQUENCY dial.  Refer to 
    TRANSMITTER 
    ALIGNMENT, 
    Section III, 
    paragraph 3t6. 
    Refer to TROUBLE 
    ISOLATION, 
    Section IV, 
    paragraph 4---16. 2 Set 
    FREQUENCY 
    dial, 100 kc 
    from high end.       3 Set COUPLING 
    at 3, and key 
    the transmitter.  Vary ANT 
    INDUCTANCE 
    from 0 upward, 
    until antenna 
    current is 
    indicated. Adjust 
    COUPLING and 
    ANT 
    INDUCTANCE 
    carefully for 
    maximum 
    antenna current.  Antenna meter 
    reads 2.0 to 3.0 
    amps. TS-
    58/GRM-1, 
    position 5, reads 
    60.80 (150-200 
    ma).  Refer to TROUBLE 
    ISOLATION, 
    Section IV, 
    paragraphs 4--15 
    and 4--16. 4 Switch to 
    VOICE. Key 
    transmitter,  Reduce 
    COUPLING to 
    zero; then 
    advance 
    clockwise until 
    antenna meter 
    reads 1.6 amps.  Antenna meter 
    reads 1.6 amps. 
    TS-58/GRM-1, 
    position 5, reads 
    20-40 (50-100 
    ma).  Refer to TROUBLE 
    ISOLATION, 
    Section IV, 
    paragraphs 4--16 
    and 4--17. 5 Same. Key 
    transmitter,  Loosely couple 
    LM frequency 
    meter to 
    transmitter and 
    adjust it for zero-
    beat with 
    transmitter 
    frequency.  Frequency as 
    indicated by the 
    LM should be 
    within .03 per cent 
    of the frequency 
    indicated on 
    transmitter dial. Refer to 
    TRANSMITTER 
    ALIGNMENT, 
    Section III, 
    paragraph 3----6. 6 Repeat Steps 3, 4, and 5 with transmitter dial set at 100 kc from low end of band. 7 Repeat Steps 3, 4, and 5 with transmitter dial set to the crystal frequency. 8 Repeat Steps 3, 4, and 5 with transmitter dial set to the operating trequency.  
    						
    							9 Lock all controls except coupling control.  
    2--29. MODULATION CHECK. 
     
    2--30. PRELIMINARY INSTRUCTIONS: 
    Modulation capabilities of the transmitter are determined by use of the oscilloscope, displaying a 
    modulation envelope type of pattern. In addition to the normal oscilloscope control settings, the 
    following should be observed: 
    Oscilloscope Settings--Vertical input to plates direct. Sync control to EXTERNAL. 
    Oscilloscope Connections-Sync voltage is obtained from one of the phone jacks in receiver rack or 
    junction box. The vertical input terminal of the oscilloscope is loosely coupled to the transmitter R-F 
    output, by attaching a wire, having good R-F insulation, to the vertical input terminal. The other end of 
    this wire is brought close to the phantom antenna lead from the transmitter. The degree of coupling 
    between these two leads will determine the vertical height of the modulation pattern. 
    STEP TRANSMITTER 
    CONTROLS  OPERATION  NORMAL 
    INDICATION  ABNORMAL 
    INDICATION  1 Set emission to 
    TONE. Key 
    transmitter. 
    Adjust 
    COUPLING 
    control for 
    maximum 
    Antenna 
    current.  Adjust sweep 
    frequency 
    controls of 
    scope until two 
    or more audio 
    cycles are 
    displayed. 
    Adjust Sync 
    control for 
    steady pattern.  Sinewave 
    envelope pattern 
    with no 
    appreciable 
    distortion; see 
    figure 2--1. 
    Modulation 
    percentage should 
    be 60 per cent or 
    better as 
    calculated by use 
    of formula below. Refer to TROUBLE 
    ISOLATION, 
    Section IV, 
    paragraph 4--17. 2 Set emission to 
    VOICE. Key 
    transmitter.  Speak in mike at 
    normal voice 
    level.  Observe that the 
    modulation peaks 
    rise to a higher 
    value than that 
    obtained for 
    normal indication 
    in Step 1. Refer to TROUBLE 
    ISOLATION, 
    Section IV, 
    paragraph 4--17. MODULATION FORMULA: (A-B)/(A+B) * 100 = % modulation  
    						
    							SUMMARY TEST DATA CHECK OFF SHEET 
    AN/ARC-5 
    Antenna Relay__________Mike Jack___________Phone Jack___________Dynamotor Ripple 
    ___________ 
    Calibration (.08%)__________Vibration____________Align Input__________Dyn. Overhaul 
    Date_________ 
    Max. Band Noise .19-.55mc .52-1.5mc 1.5-3.0mc 3.0-6.0mc 6.0-9.1mc 
    (15 mw) ________ ________ ________ ________ _________SENSITIVITY HIGH END LOW END 
    AVC CHARACTERISTICS 
    (7uv) CW MCW INPUT OUTPUT 
    RATIO LIMITS 
    .19-.55mc _________________ _________________ NOR. SENS. ________ uv. (mw) 
    .52-1.5mc _________________ _________________ 5X ________ 50-1001.5-3.0mc 
    _________________ _________________ 10X ________ 50-150 
    3.0-6.0mc _________________ _________________ 100X ________ 100-200 
    6.0-9.1mc _________________ _________________ 1000X ________ 100-300 
    10000X ________ 200-400 AUDIO OUTPUT CW ________ MCW ________ 200 200 
    SELECTIVITY 
    RECEIVER .19-.55mc .52-1.5mc 1.5-3.0mc 3.0-6.0mc 6.0-9.1mc LIMITS 
    2X ________ ________ ________ ________ _________ 2X -- 2.1-10 kc 
     
    10X ________ ________ ________ ________ _________ 10X -- 5-10 kc 
    10000X ________ ________ _________ ________ _________ 10000X -- 18 kc 
    TRANSMITTER POWER TRANSMITTER TRANSMITTER TRANSMITTER 
    OUTPUT FREQUENCY MODULATION TUNE-UP 
    CW __________ 
    26 to 40 CW _________ VOICE _________ VOICE _________ 
    .05% Approx. 70% Max. ant. 
    current 
    TONE __________ 
    13 to 26 
    VOICE __________ CHANNEL SEL. POWER SUPPLY 
    13 to 26 1 ______ 2 ______ IN _______ OUT ______ 
    27.5Vdc 545Vdc 
      
    						
    							SECTION III ALIGNMENT PROCEDURE 
     
    3--1. RECEIVER ALIGNMENT.  
    Figure 3-1. Receiver Alignment Connections  
    Figure 3-2. Location of Trimmers, Typical Receiver  
    						
    							3--2. PRELIMINARY INSTRUCTIONS.Output Meter--Daven, Model OP-182, connected into headset jack on 
    receiver rack; IMPEDANCE SELECTOR set at 300 ohms.  
    Signal Generator--LP-5 or Hickok 19X connected between the point indicated on alignment chart and ground. 
    Controls-Set gain control at maximum, emission to MCW, signal generator switch ON, and dial as indicated in 
    chart. 
    Output Level--During alignment, the signal generator output must be attenuated to maintain the receiver output 
    at 10 mw as indicated by output meter.3--3. RECEIVER ALIGNMENT NOTES.3--4. The receivers R-23, R-24 
    and R-23A normally operate with over-coupled I.F stages. For alignment, each I-F stage must be loosely coupled 
    by pulling out the bakelite rod to the snap-out position. After the entire alignment is completed, the I-F stage 
    must be returned to the same over-coupled condition. For the R-23 and R-24, over-couple the first I-F stage; for 
    the R-23A and R-148, over-couple all I-F stages. 
     
    3--5. RECEIVER ALIGNMENT PROCEDURE. (See figures 3--1 and 3--2.) Before beginning alignment, check 
    the positions of C4F and C4G and adjust them if necessary  
    to the position shown in the table which follows. The positions shown are as seen from the FRONT of the 
    receiver. 
     
    RECEIVER C4F C4G R-23 
        R-24 
        R-25 
        R-26 
        R-27 
         
    Front of Receiver 
     
    SIGNAL GENERATOR RECEIVER STEP 
    CONNECTIONS 
    TO RECEIVER FREQUENCY 
    SETTINGS TYPE DIAL 
    SETTING SPECIAL 
    INSTRUCTIONS TRIMMERS 1 Through .006 
    mfd capacitor to 
    mixer grid use 
    MOD RF.  85 kc  
    239 kc  
    705 kc  
    1415 kc  
    2830 kc  R-23 
    R-24 
    R-25 
    R-26 
    R-27  ANY 
    DIAL 
    SETTING  See Receiver 
    Alignment Note, 
    paragraph 3--3. 
    Adjust all I-F 
    trimmers as 
    indicated at 
    right, for 
    maximum output 
    meter reading.  C-21  
    C-38  
    C-37  
    C-18  
    C-36  
    C-13 2 Same Use 
    PURE RF.  Same  
        Switch receiver 
    to CW and 
    adjust BFO 
    trimmer for zero-
    beat. C-28  
    						
    							3 Same Use MOD 
    RF.  .52 mc 
    1.4 mc  
    2.9 mc  
    5.8 mc  
    8.9 mc  R-23 
    R-24 
    R-25 
    R-26 
    R-27  .52 mc 
    1.4 mc  
    2.9 mc  
    5.8 mc  
    8.9 mc  Switch to MCW. 
    Adjust oscillator 
    trimmer for 
    maximum output 
    meter reading. C-4E 4 Through .006 
    mfd capacitor to 
    ANT post.  Same  
      Same  Adjust R-F 
    trimmer and 
    ALIGN INPUT 
    trimmer for 
    maximum 
    output.  C-4D  
    C-2 5 Same  Same  
      Same  Adjust oscillator 
    trimmer for 
    maximum 
    output. C-4E 6 Same  
    .21 mc  
    .57 mc  
    1.55 mc  
    3.1 mc  
    6.1 mc R-23 
    R-24 
    R-25 
    R-26 
    R-27  .21 mc  
    .57 mc  
    1.55 mc  
    3.1 mc  
    6.1 mc Adjust oscillator 
    padder, while 
    carefully rocking 
    the receiver dial, 
    for maximum 
    output. C-9 7 Repeat Steps 5 and 6 two or more times until there is no further increase in output when 
    Step 5 is performed. Then, proceed with Step 8. 8 Same Use 
    PURE RF.  Same as 
    Step 5    Same as 
    Step 5  Switch to CW. 
    Adjust oscillator 
    trimmer for zero-
    beat. C-4E 9 Return I-F transformers to overcoupled condition: See Receiver Alignment Note, 
    paragraph 3--3.   
    						
    							Figure 3-3. Transmitter Alignment Connections)  
    Figure 3-4. Transmitter Adjustment Points (Top)  
    Figure 3-5. Transmitter Adjustment Points (Bottom)  
    						
    All ARC manuals Comments (0)