HP 4935A, Operating And Service Manual

Page: 26 / 350

Model
Operation
1 .
9 .
CONTROLS, CONNECTORS AND
Power Cord Module. Accepts power cord supplied with instrument. Contains line fuse and PC
board for selecting line voltage (see Section II, paragraph 2-9 for procedure to select line voltage).
Always connect power cord to a proper y grounded power outlet.
!
Do not connect more than 200VDC signal to terminals.
POWER button. Switches power to front panel in ON position. In STBY position power is
still applied to some circuits. If unit has battery option there will still be power available to some
internal circuits even in STBY position.
NOR and REV switches. NOR switch depressed connects the left 310 jack to the transmitter and
the right 310 jack to the receiver. REV switch depressed connects the left 310 jack to the receiver
and the right 310 jack to the transmitter. Both switches out simultaneously or depressed
simultaneously internally loops the transmitter to the receiver.
DIAL Binding Posts. Handset can be connected to binding posts to dial-up a line through the 310
SET UP Switches.
13512, Provides terminating impedance to match the lines’ characteristic
impedance.
DIAL: Disconnects TRMT-RCV 310 jack from the transmitter and connects the TRMT-RCV 310
jack
to the DIAL binding posts.
HOLD: Connects the hold circuits to the TRMT-RCV 310 jacks to hold dial-up lines.
13512, 60011, 90012: Provides terminating impedance to match the lines’ characteristic
impedance.
Connects the RCV-TRMT jack through impedance when the bridges
the circuit under test instead of terminating the line.
HOLD: Connects the receive-hold-circuits to the RCV-TRMT 310 jack to hold the dial-up lines.
Key. TKMT-RCV. Selects either the transmitted or the received to be displayed.
will
Key. Prevents the transmitter from transmitting within Hz Hz band) of a
frequency. This feature eliminates accidental disconnection by SF signaling units
dial-up lines. Operates only in will light when key is pressed.
ZERO Key. Sets a 0 reference in KCV mode. All subsequent
measurements will be made in relative to this reference. in center of front panel will
A (minus) reading indicates levels higher than the reference level per the telephone
industry convention.
U P , S T E P D O W N , and K e y s . I n TRMT Mode (right display) and LEVEL
or selects the position of digit to
be
increased or decreased. Lighted cursor
indicates one-of-five digit positions. Digit value is incremented
by
pressing STEP UP and
decremented by pressing STEP DOWN. Holding the STEP UP or STEP DOWN key depressed
causes
the actions to
Figure Front and Rear Panel Controls/Connectors/Indicators (Continued)