SCALE -MASK ASSEMBLY.

c. Unsolder the three swivel-support assembly leads (X, Y, Z)

and remove the assembly.

NOTE

If desired, the pivot blocks and washers may

now be replaced.

d. Position the new swivel-support assembly so that the strobotron

tube socket and leads (X, Y, Z) can be mounted as shown in Figure 4-4.

e, Insert leads (X, Y, Z) through the slot between screws (B),

and hold the swivel-support assembly in position between the two pivot

blocks. Slide the pivot blocks together and tighten nuts (A). The pivot

action of the swivel-support assembly may need adjustment; if so,

loosen one nut (A), adjust the corresponding pivot block, and tighten

the nut again.

f. Solder leads (X, Y, Z) to terminals (see Figure 4-4).

4.7.3 SCALE -MASK ASSEMBLY.

To replace the scale-mask assembly:

a. Set the range switch to the 4000-25,000 RPM position.

b. Loosen the two setscrews in the scale-mask assembly hub

and remove the assembly from the range-switch shaft.

Figure 4-4. Internal view of Type 1531

Strobotac. Lead connection terminals

and mounting of swivel-support assembly.