5267 



HYDROGRAPHIC MANUAL 



Page 492 



5267. Diagnosis of Faulty Operation or Failure 



Table 17 is furnished for use in diagnosing the cause of faulty operation or failure of the Dorsey 

 Fathometer No. 3. Each line in this table represents one case of faulty operation. Each case is 

 described by the position of the X-marks in the first 10 columns of this table and the switch positions 

 under the heading "Setting of functional switches." The X-marks are to be considered as referring 

 to a faulty condition, normal operation being inferred by blank spaces in any of the 10 columns. 

 The reference numbers, entered in the column headed "Parts involved," refer to the items in table 

 14 that may be wholly or partly responsible for the trouble. These numbers must not be confused 

 with terminal-post numbers. The letters in the last column of table 17 refer to the explanatory 

 paragraphs identified with corresponding letters that follow table 18. It is assumed that the power 

 switch inside the indicator cabinet is turned on, and the shoal-deep switch is on the deep position. 



To aid in interpreting this table, assume the following case of faulty operation : With the starting- 

 frequency switch on position 4, no matter whether the depth-selector switch is on position 1, 2, 3, 

 or 4, there is no registration on the 20-fathom dial of transmitted signals, of echoes either at normal or 

 high gain of the echo amplifier, or of strays at high gain of the echo amplifier; but all are registered 

 normally on the 100-fathom dial — that is, on the two positions of the depth-selector switch which 

 connect the 100-fathom index neon-tube circuit as given in table 16. A case of faulty operation 

 thus characterized is dealt with in the fourth line of table 17. 



Table 18. — Circuit voltages of Dorsey Fathometer No. S 

 (This table assumes 60-cycle line supply of 110 volts which is the value at which the instrument should normally be operated.' 



Terminal 



post 

 number 



Voltage or current 



Indicator 

 D-C Supply: 



Index neon tubes (polarizing) 



Plate circuit of type 885 tubes j 



Grid circuit of type 885 tubes 



Keying Circuit: 



Anodes of photoelectric tubes 



Cathode of type 2^13 tubes and plate of type 6F5 tubes 



Plate of type 2^3 tubes (and grid circuit of type 59 oscil- 

 lator) . 

 ' Plate load resistor of tj'pe 2^13 tubes (and cathode circuit 

 of type 59 oscillator). 

 Drop across load resistor of type 2^13 tubes (which is the 



bias for type 59 oscillator) . 

 Keying relay in plate circuit of type 807 tubes 



Power Supply 



17.5-Kc Oscillator Circuit: 



Grid circuit of type 59 oscillator (and plate of type 2^3 



tubes). 

 Cathode circuit of type 59 oscillator (and plate load resistor 

 of type, 2^13 tubes). 



Screens of type 59 oscillator 



Plate circuit of type 59 oscillator ■ 



17. 5-Kc Power Amplifier: 



Grid circuit of type 807 tubes 



Screens of type 807 tubes 



Plate circuit of type 807 tubes 



Grid circuit of type 838 tubes 



Plate current of type 838 tubes (key down) 



17.5-kc current to transceiver (key down) 



\025-Cycle Power Supply: 



Grid circuit of type 6C5 tubes 



Plate circuit of type 6C5 tubes (and screen of type 6F6 

 tubes) . 



Plata circuit of type 6F6 tube 



Plate current of type 838 tubes 



1025-cycle current to synchronous motor 



32-33 



7 

 8 



36 



350-375 volts. 

 270 volts. 

 — 45 volts, 



83 volts. 

 200 volts. 

 265-275 volts. 



500 volts. 



225-235 volts. 



1,100-1,300 volts. 



265-275 volts. 



500 volts. 



700 volts. 

 1,000 volts. 



— 50 volts. 

 200-250 volts. 

 1,000-1,200 volts. 



— 230 volts. 

 160 ma. 

 0.58-0.60 ampere. 



(Approx) —2.3 volts. 

 225-250 volts. 



315 volts. 

 180-200 ma. 

 0.8-1.0 ampere. 



