SECTION 502-500-120
KEY CODE NO.
BASEPLATE
COIL SPRING
LATCH BAR
Fig. 13-589-Type Key, Top View
MIN CLEARANCE
BETWEEN
SPRINGS
1/64
INCH
P-18AB59 VIBRATION
DAMPER SLEEVE
Fig. 14-589-Type Key, Bottom View
3.16
Replace set if the following requirements
cannot be met:
•
When depressed, locking plunger should
release any previously locked plunger on
its downstroke.
•
When any pushbutton plunger is released
from its operated position, it should return
with a snap to its nonoperated position.
Page 10
10 Pages
•
An operated key plunger should not release
during downstroke of hold button.
•
An operated key plunger should release from
its operated position on the upstroke of the
hold button.
•
A turnbutton operated plunger, when rotated
90 degrees clockwise, should maintain its
operated position.
•
When rotated counterclockwise from its
operated position, it should be self-restoring
the last 30 degrees of rotation.
241-Type Amplifier
3.17
Used in telephone sets with headset jacks
to a m p lify the o u t p u t of the headset
transmitter.
NO
FIELD
MAINTENANCE SHOULD
BE ATTEMPTED ON 241-TYPE AMPIJFIERS.
3.18
The 241A "Series II" or 241B amplifier
must be used on all 563HB, 1563HB, and
2563HB sets to eliminate mechanical interference
with the exclusion plunger.
3.19
Replace a 241-type amplifier if it is suspected
of being defective (as evidenced by poor or
no transmission).
TOUCH-TONE Dial
3.20
Check line polarity if no tones are heard in
the receiver when a button is depressed.
The 25- and 35-type
dia
l
will
function
only when the green
dial
lead
is
positive
(
+)
and when the orange-black lead
is negative(-).
3.21
A hand test set connected to line terminations
can be used to test for defective dials.
Do
not attempt repairof TOUCH-TONE
dials in the field. Replace defective
dials.
BSP
502-500·120·103_1974-11-lO.jpg Scanned by Frank Harrell, {Cowboy Frank) Castle Rock, Colorado Feb 02,2012 19:00:47
