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I
SAFETY PRECAUTIONS I
NOTICE : Observe all cautions and safety related notes located inside the receiver cabinet and on the receiver chassis.
WARNING
1. Operation of this receiver outside the cabinet or with the cover removed presents a shock hazard from the receiver power
supplies. Work on the receiver should not be attempted by anyone who is not thoroughly familiar with the precautions
necessary when working on high-voltage equipment.
2. Do not install, remove or handle the picture tube in any manner unless shatter-proof goggles are worn. People not so
equipped should be kept away while the picture tube is being handled. Keep the picture tube away from the body while
handling.
X-RADIATION WARNING
The surface of the picture tube may generate X-Radiation. Take precautions when servicing and, if possible, the use of a lead
apron is recommended for shielding while handling.
When replacing the picture tube, use only the designated replacement part since it is a critical component with regard to X-
Radiation as noted above. No high-voltage adjustments are provided. The high-voltage specification is described on the cover
page.
LEAKAGE CURRENT CHECK
·-·3efore returning the receiver to the customer, it is recommended that leakage current be measured according to the following
·'"'methods.
·
1. Cold Check
With the AC plug removed from the AC source, place a jumper across the two AC plug prongs. Turn the receiver AC switch on.
Using an ohm-meter, connect one lead to the AC plug and touch the other lead to each exposed metal part (antennas, handle
bracket, metal cabinet, screwheads, metal overlays, control shafts, etc.), particularly any exposed metal part having a return
path to the chassis. Exposed metal parts having a return path to the chassis should have a minimum resistance reading of 1
megohm. Any resistance below this value indicates an abnormality which requires corrective action. Exposed metal parts not
having a return path to the chassis will indicate an open circuit.
2. Hot Check
Use the circuit in the Figure below to perform this test.
(1) With switch S1 open, connect the receiver to the measuring circuit. Immediately after connection, measure the leakage
current using both positions of. switch S2, and with the switching devices in the receiver in all of their operating positions.
(2) Switch S1 is then closed, energizing the receiver. Immediately after closing the switch, measure the leakage current using
both positions of switch S2, and with the switching devices in the receiver in all of their operating positions. Current
measurements of items (1) and (2) are to be repeated after the receiver has reached thermal stabilization. The leakage
current must not be more than 0.5 milliampere.
S1
(Grounding)
Open
Grounding Supply Conductor
-1-
Insulating Table
B
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