HP 6268B Operating And Service Manual

2-25 To convert these 230-volt instruments to 11 5-volt
operation, proceed as follows:
a. (Omit this step for the Model 6259B.) Obtain and
install a new circuit breaker CB1. Refer to Option 026 in
the Table 6-4 parts list for its current rating and HP Part
Number. Connections to the replacement are the same as
those to the original breaker.
b. Remove and partially disassemble the A2 RFI
assembly as described in steps (a) through (d) of paragraph
5-65.
c. Unsolder jumper J3 from the A2 circuit board (see
Fig. 7-1) and install jumpers J1 and J2. Also install
resistor A2R3 on the circuit board. Refer to Option 026
in the Table 6-4 parts list for its description and HP Part
Number. Replace cover on RFI assembly.
d. Locate the wire that connects circuit breaker CB1
to the A3T2 bias transformer terminal marked "230V”,
disconnect it from the transformer, and reconnect it to
the terminal marked "115V." Also disconnect the wire
from fan B2 (not used in the 6259B) from the terminal
marked "230V" and reconnect it to the terminal marked
"0V” (see Fig. 2-2C).
e. Re-install the RFI assembly by reversing the
procedure of step (b).
f. Unsolder the jumper connecting terminals 2 and 3
of power transformer T1 (see Fig. 2-3C) and solder jumpers
between terminals 1 and 3, and 2 and 5.
2-26 Converting a Standard Instrument to 115-
Volt Operation (Model 6260B)
2-27 To convert the standard Model 6260B to 11 5-volt
operation, proceed as follows:
a. Obtain and install a new power transformer (T1) and
a new circuit breaker (CB1). Refer to Option 016 in the
Table 6-4 parts list for their description and HP Part
Number. The new transformer has two primary terminals.
Transfer the wire from the ”0V" terminal on the old trans¬
former to the "0V" on the new one, and from the ”230V”
terminal on the old one to the "115V'' terminal on the
new one. The connections to the replacement circuit
breaker are the same as to the old one.
b. Perform steps (b) through (e) of paragraph 2-25.
2-28 Converting a Standard Instrument to 50Hz
Operation
2-29 To convert a 60Hz instrument to 50Hz operation,
proceed as follows:
a. Replace A1 R82 with a 240 ohm 5% 1/2-watt resistor.
Refer to the Table 6-4 parts list under Option 005 for the
HP Part Number of a suitable replacement.
b. After replacing A1 R82, perform the preregulator
tracking adjustment given in paragraph 5-102.
c. Check the ripple balance adjustment by the procedure
given in paragraph 5-100.
2-31 No input power cable is supplied with the instru¬
ments covered by this manual. Input power connections
are made to a 3-terminal barrier block on the rear panel.
Its center terminal is grounded to the instrument chassis.
To protect operating personnel, the National Electrical
Manufacturers Association (NEMA) recommends that the
instrument panel and cabinet be grounded. The user-
supplied power cable should have three conductors (with
the third conductor grounded) and should be of adequate
wire size to handle the input current drawn by the supply
(see paragraph 2-15). Note that when the supply is opera¬
ted from a 11 5-volt source, the input current is approxi¬
mately twice that shown in paragraph 2-1 5.
2-3

HP 6268B Specifications

General

Brand	HP
Model	6268B
Category	Power Supply
Language	English