Repair manual

as it occurs during an untimed period in the shutter

operation.

However, the upward spike marks the instant the switch starts

to close and therefore is an important marker.

Refer now to the preferred picture for 1/50 second shutter

and switch timing shown in section 24.100 – J the point “A”

marks the start of the shutter opening and “D” the point when

the shutter is fully opened, “E” the point when the shutter

starts to close, and “F” the final closing of the shutter.

During the interval from “S” to “D”, however, the switch has

closed. “B” marks the time of initial contact of the switch

members and “C” is the time of full electrical contact. The

point “C”, then, is the point when the flash bulb would be

connected to the batteries in the flash gun in actual flash

photography.

For proper flash photography, the point “C” should occur

almost simultaneously with “D”. This allows almost the full

shutter timing interval for the flash bulb to heat up to the

flashing temperature and to remain bright the duration of it’s

flash before the shutter closes.

K - If the picture at 1/50 second looks thus:

A F

The switch is making poor contact and bouncing. Adjust switch

so that contacts are separated about 1/64 inch (.006 Min.)

when the release button is out, bending the heavy brass switch

blade to adjust to 1/64 (.006 Min.)

If necessary, bend moving switch blade to insure a contact

pressure at least 4 grams, and bend the drive blade hook to

give maximum clearance with the moving switch blade in the

closed position. Switch bounce is usually caused by

insufficient clearance between the hook and the moving blade

when the switch is closed or insufficient contact pressure.

L - If picture looks like thus:

Bend the finger of the switch drive blade to contact the

shutter blade ear earlier and bend drive blade hook to permit

contacts to close earlier. In adjusting the switch drive

blade finger, be sure that it is not bent far enough to ride