Section II. OPERATORS CONTROLS AND INDICATORS

10. Damage From Improper Settings

I m p r o p e r setting of the FILAMENT RANGE switch (fig. 3) or

incorrect operation of the PRESS TO TEST switches may damage

the tube under test. Be sure that all the controls and switches are

set properly before inserting the tube in the socket.

11. Operating Controls and indicators

(fig. 3)

a. Controls.

Function

Control

ON-OFF switch . . . . . . . . . .......... In ON position, applies ac power to unit.

PRESS TO TEST (switches P1 Depending on type of test selected, de-

pressing one or more switches applies

through P6).

power to tube under test.

SHORT TEST (6-position rotary In OPER. position, permits all tests ex-

cept short test. By turning switch

switch ).

successively through positions V, W,

X, Y, and Z, various tube electrodes

are tested for interelement shorts.

Switch

FUNCTION (3-position rotary

position

Action

TEST ---------- Permits all types of tube

switch).

Note. On some equipment this switch

tests except voltage reg-

is marked LEAKAGE VR.

ulator and leakage tests.

VR--------------- Permits tests of thyra-

trons and voltage regu-

lator tubes in conjunc-

tion with PRESS TO

TEST P5 switch.

LEAK . . . . Permits determining in-

terelement leakage in

megohms as indicated

by PLATE meter.

Seven SELECTORS switches:

Turning each of the filament switches to

FIL- and FIL+ 12-position

rotary switches.

one of positions 1 to 9 connects fila-

ment voltage to correspondingly num-

bered base pin of tube under test. (0

is no connection.)

Turning the switches to position A or B

connects filament voltage to A or B

electrical clip, respectively.

GRID (12-position rotary switch) - When set to one of positions 1 to 9, con-

nects grid bias and signal voltage to

correspondingly numbered base pin of

tube under test. (0 is no connection.)

In A or B, connects grid bias and

signal voltage to A or B electrical clip.