Teletype 28 - Page 98

SECTION 573-118-700TC
3.18 Contact Timing Me1.surements for LTRS-FIGk Contact (Later Design) (For
Earlier Design see 4. 05)
Note: If unit is equipped with code
reading and/or timing contacts,
test is to be made after installa-
tion and adjustment of these contacts.
START OF LETTERS-
FIGURES CONTACT
LETTERS-FIGURES CONTACT TEST
To Check
END OF LETTERS-
FIGURES CONTACT
I
MIN OF 5 DIV
END
OF RIGHT
SIDE
OF FRONT
TIMING CONTACT
Connect cable leads of letters-figures contact to neon trace lamp of signal distortion
test set. Set control switches of test set to following positions: (1) VIEW-TRANSMIT
switch to VIEW; (2) LINE-DIST. switch to LINE; and (3) MOTOR switch to ON.
Alternately select LETTERS (12345) and FIGURES (12-45). Set START-ZERO MARK
of test set scale at start of contact trace. Connect right side of front timing contact
(probe) to neon trace lamp; record start and end of trace. Reconnect letters-figures
contact to trace lamp and alternately select LETTERS and FIGURES.
(1)
Requirement
No chatter or bounce of letters-figures contact during time when timing contact
is closed·-------------------------------------------------------------------~
To Adjust
If requirement is not met, refine MIDDLE CONTACT SPRING and LOWER CONTACT
SPRING (3. 12)
adjustments.
(2) Requirement
Trace of letters-figures contact start minimum of 40 divisions before start of trace of
timing contact and end minimum of 5 divisions after end of timing contact.
To Adjust
If requirement is not met, refine MOUNTING BRACKET (3. 12) adjustment.
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