47« When the switch is in the . position, the motor power supply 

 is controlled by the automatic switching unit which will switch on the motor 

 even if the ■■ switch is off, This will cause paper to be fed through the 

 recorder,, even though no record will be made on it. If the switch is 



' , however, the jewelled pilot lamp will glow, the tubes will be heated, and 

 the recorder will operate either manually or by the action of the automatic 

 switching unito 



48 , A study of Fig, 38 will show that the input to the "slow-speed" graphic 

 level recorder is permanently bridged across the system bus and that except 

 for the reception of broadcast time signals, it cannot be energized from 

 any other source. The "high-speed" recorder, on the other hand, can be 

 energised from the system bus ?r from either magnetic tape recorder, and 

 may also be used to record broadcast time signalsc The selection of I 

 or (mirrophone) and of or is con- 



trolled by and 5-102 on the front of the third panel from the top of 

 Rack 1 (Figo 2), the time tone amplifier chassis. 



Speed Controls 



49° Located to the left and slightly back of the power control switches 

 is a gear box with two indicator knobs on its top (Fig, 23) „ The left 

 knob is labeled and controls the speed with which the scriber moves 

 across the tape. In the center or position it disengages the scriber j 

 turned to the left it gives operation and to the right : operation ■• 

 The right knob is labeled and also has a center or neutral 



position, a left position of . , and a right position of 



50o With these two knobs paper-tape delivery speeds of 1, 5, 10, and 50 mm< 

 per second can be obtained. The normal position for the "slow-speed" graphic 

 level recorder in Rack 2 is with" the control on and the 

 speed control on r This combination gives a resulting paper tape speed of 



5 mm per second. The "high-speed" graphic level recorder in Rack 3 is normally 

 used with its control on and its speed control on 



This combination gives a resulting paper tape speed of 10 mm, per second* 



51 o Although it is possible to use the control to start and stop 

 the paper feed,, the controls should in general be set as described above 

 before the recorder is turned on. If the control is used for 

 starting and stopping, the time indexing space interval should be measured 

 to see that it remains at 5 or 10 mm per second j if the interval changes 

 the time evaluation will be impaired „ Too much force exerted on the control 

 knob to effect clutch engagement may introduce a slight bind in the paper 

 tape feed and affect the spacing of the time indexes. This difficulty is 

 not so likely to occur with the 10 mm per second speed setting as with the 



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