HP 3562A Service Manual page 142

ADJ USTM E NTS
Description:
3-9 INPUT DC OFFSET ADJ USTM ENT
This proced u re centers the offset DAC on the ADC board to allow it maximum correction
range in either the positive or negative direction.
Equ ipment Req u i red:
Extender board (part of kit 03562-84401 ) . . . . . . H P 03562-66542
Instrument power should always be turned o ff before any boards
are remo ved or installed. Failing to do so causes circuit failure in
Procedu re:
most cases.
1 . Disconnect the l i ne power cord from the rear panel of the H P 3562A.
2. Remove the I nput board (A33)
sure to reconnect the coax between the input board and its accompanying ADC board.
3. Remove the ADC board of the same channel as the input board u nder adj ustment
and ground TP400. Rep lace the board in the i nstrument.
4. Short all three pins of the in put connector A33J300 and
center pin of the in put connector is grou nd, this grou nds the input signals and TP501 .
5. Reconnect the l i ne power cord and tu rn the power switch ON.
6. Press the fol lowing keys in the order given:
RANGE
I N P U T
x
C O U P LE
To adjust channel two, also press:
7. Adjust A33R21 2 for a marker ampl itude read i ng of less than - 85 dB on the H P 3562A
MEAS D I S P
disp lay.
8. Remove the ground con nection from A33TP501 .
3-1 4
CAUTION
be adj usted and place it on the extender board. Be
to
. . . . . . . dBVrms
- 51
·
. . . Select dc cou pling
. . . (Tu rn on the X marker at freq uency having the largest
·
magn itude; in this case it should be 0 Hz)
·
. . . POW E R SPEC2
·
MO D E L 3562
together. Si nce the
A33TP501