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SJ, SJa, SJ-1 SUBMARINE SURFACE SEARCH RADAR


Pictorial view of SJ installation
Pictorial view of SJ installation

Description.-A 10 cm surface-search and torpedo- control for installation on submarine.

Number of operators.-One.

Power supply.-SJ-1.5 kva, 115 V, 60 cps. SJa, SJ-1-1.4 kva, 115 v, 60 cps.

                      SJ   SJ-1
Maximum reliable
  range (miles):
  Bombers, 500 ft.    5.    5.
  Battleships         8.   12.
  Cruiser             8.   12.
  Destroyers          6.    8.
  Submarines (sur-
    faced)            3.    6.
  Beacons S Band  Horizon. same.
Resolution:
  Range (yd.)        50.   50.
  Bearing (deg.)      5.    5.
Accuracy:
  Range (yd.).   25+-.l%.  15+-.1% (precision sweep).
  Bearing (deg.)  +-0.3.  0.3 degree (with lobe switch).
Minimum range (yd.) 250.  250.
Indication and data output:
Range: 5-inch A-scope with range step and dial. Main Sweep: 60,000 yd. Expanded Sweep 20,000 yds. Precision sweep on 40,000 yds. 1,500 yds. either side of mark.
Bearing: Relative bearing read from train indicator. Pip match is optional.
PPI: A 5-inch PPI is provided with SJ-a and SJ-1
Ranges: 8,000, 20,000, 80,000 yd. 160,000 yd. delayed sweep.
Other: Provisions for IFF indication are present.
Transmitter specifications:
 Frequency (Mc)               3000.
 R-f source                   Magnetron, 606AY.
  R-f lines                   Wave guide.
  Pulser type                 Thyraton-SJ; Peterson
                                Co: 1 SJ2.
  R-f peak power (kw)         SJ-20; SJ-1-50.
  R-f  average power (kw)     0.018-SJ.
  Pulse rate (pps.)           SJ-600 & 1800; SJ-1-
                                1500+-150.
  Pulse length (micro second) 0.25.
Receiver specifications:
  Type                        Superheterodyne.
  Stages.                     6 i-f; 3 video.
  Local oscillator            707A; SJ-1-726B.
  Intermediate frequency (Mc) 60.
  Band pass (Mc).             5 i-f; 5 video.
  Mixer Crystal               SJ-1;  grounded.
                               grid triode-SJ.
  Noise, db above theoretical. 10.
Antenna specifications:
 Total weight (lbs.)          SJ-300; SJ-1-330.
 Feed                         Wave guide.
 Reflector:
  Old type                    Solid unhoused reflector.
  New type                    Slotted.
  Shape                       Truncated paraboloid.
  Size                        SJ-10" high x 30" wide.
H.P. beam width:
  Horizontal                  9 degrees.
  Vertical                    29 degrees.
Polarization                  Horizontal.
Gain (db)                     19 (SJ-1).
Scan                          Continuous rotation
                              through 360 degrees at 1 to 8
                              r.p.m. by motor or it
                              may be trained manually.
                              Left-right  lobe switching.
                              Divergence is 5 degrees.
                              Elevation fixed.
Tube complement.-1 type 705A, 1 type 706A or 706AY, 1 type 707A, 1 type 708A, 1 type 709A, 1 type 713A, 1 type 722A, 1 type 2X2/879, 1 type 5HP1, 4 type 5U4G, 1 type 6AB7, 14 type 6AC7, 1 type 6H6, 10 type 6L6, 10 type 6SN7GT, 4 type 6SQ7, 2 type VR-105/30, 3 type VR-150-30, 1 type 813, 2 type 836, 4 type 991.
          Dimensions and weights (SJ-1)
       Unit         Navy Type  Length   Width     Depth  Weight   Pampanito
                    No.        Inches   Inches    Inches Pounds   Serial #
Antenna assembly   CW-66AFC    31 1/2   30        15       350
Transmitter  re-   CW-43AAF-1  20 5/8   18 7/8    13       190   #12,C.T.
 ceiver.
Range indicator    CW-55AAL-1  16 3/4   11 3/8    20 3/4   110
Plan position in-  CW-55ADE    14 3/8   13 1/8    19 7/8   120   #6,C.T.
 dicator.
Range unit         CW-23ACC     6 9/16   9 1/2    18 3/4    67   #67,C.T.
High voltage rec-  CFZ-2OAAR-1 10 5/16  12        18 7/16  100   #6,P.R.
 tifier.
Regulated  recti-  CFC-2OAAQ   18 1/4   10 21/32  17 5/8   115   #6A,6B P.R.
 fier (2).
Main control unit. CFC-23ADH   14 1/4   15 1/4    13       125   C.T.
Bearing indicator  CW-55ADD     8       12         8        20   C.T.,C.R.
Motor generator    CW          12       37 3/4    12       110
 control unit.
Adapter  control   CW-23ABX     5 3/4    5 3/4     4 5/8  6 1/2  C.T.,P.R.
 unit.
Junction box (2)   CW-62AAB    14       17 9/16    4 5/8    32
Motor generator    CG-21AAS    15 1/8   13 7/16   44 3/8   450
 set.
Range transmitter               6 1/2    9 1/32    9 1/2    26
Test Equipment.-ABM wave meter and OBU echo box included.      OBU,C.T.
Literature.-SJ instruction book (Eng. 188). SJ-1 instruction book (Ships 258).

REFERENCES:

The information enclosed here is excerpted from:
Catalogue of Naval Electronic Equipment-April 1946- NavShips 900,116.

 

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Version 2.00, 11 Sep 2006