Teletype 28 - Page 23

ISS 8, SECTION 573-118-700TC
2.13 Selector Mechanism (continued)
SELECTOR RECEIVING MARGIN (continued)
Note 1: Typing reperforators operating with 30 milliampere selector coil
current with coils in series should have receiving margin tests run at, and
meet the requirements for 100 wpm speed, 60 milliampere selector coils
in parallel. Testing at 30 milliampere is not required.
Note 2: Units employing TP319204 and TP327383 selector assemblies should
have receiving margins performed with the selector under test being driven
by a TP323810 selector :;nagnet driver (SMD). The distortion test set must
interface with the SMD, ie, rectangular waveform with +6 volts corresponding
to the marking state and -6 volts corresponding to the spacing state. The
specified distortion limits apply to the signal driving the SMD rather than the
selector coils. The receiving margin of the selector should conform to the
minimum requirements listed below:
Speed in
WPM
100
Points Range
With
Zero
Distortion
70
Overall Bias
35
End Distortion Tol-
erated With Scale at
Bias Optimum Setting
30
To adjust, refine the SELECTOR ARMATURE SPRING (2.04 or 2.05) adjustment.
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