The Norden Bomb Sight manual

;. Installa-

tion of

the Double

Cable.

(d) Turn

the tachometer shaft a few

revolut-

ions to

determine

that a one to one ratio has been

established.

Fine

adjustments can be made by mov-

ing the

T-arm between

788 mils.

(e) Turn telescope motor

"on".

(f) Set up maximum disc speed, and run for ap-

proximately flve

(g) Check pencil marks to insure that no slip-

page has occured.

(h)

Run disc for 15 seconds and check for

slippage.

Clutch in disolacement knob clutch.

Set telescope at maximum sighting

(k)

Repeat. step (h) and check

angle.

for slippage.

3.

if there is

any roller slippace it should not

exceed 1/3 of the circumference of the roller.

4.

If there is

too much

slippage check for:

(a)

Weak disc spring.

(b)

roller and

disc.

(c)

Toc much friction.

(d)

Telescope drive gearing and gear shafts.

(e)

Telescope return spring tension.

Flat spot on roller.

THIS CABLE SELDOM BREAKS THROUGH ORDINARY USAGE

AND REPLACEMENT SHOULD NOT BE NECESSARY UNTIL SIGHİ

IS SENT TO DEPOT FOR OVERHAUL.

a. Remove the telescope cable.

Remove #4 sheave and remove the telescope

cradle from

C.

Release all of the spring tension of the

telescope return

spring,

so that

the number six

sheave

can be positioned in order that the cable

come off tangent.

Fasten the double cable to the gear sector.

With the gear sector pointer aligned with

the cradle pointer, place the double cable on the

sheave,

taking up

all slack and

fasten the cable

number six

sheave so that the cable comes

tangent.

Cut off excess length of the cable.

g. Wind the telescope

return spring to the

approximate

tension and test with an eight ounce

weight

hanging

from an old

length

of telescope

attached

to the number five sheave.

This

weight should

align the gear sector pointer with

center of the telescope tube.

(i)

b.

will

just

d.

e.

to

the

off

f.

cable

the