Vertical High Frequency Compensation

Calibration Procedure For Oscilloscope Os-266(P)/U And Types 7844/R7844 Page Navigation
16

TB 9-6625-2131-24

(4) Move time base to B HORIZ compartment and standardizer to LEFT VERT

compartment.

(5) Set BEAM 1 and BEAM 2 VERTICAL MODE switches to LEFT and adjust

standardizer POSITION control to align bright center trace with crt horizontal graticule

center line. If trace does not align with each graticule line within 0.5 minor division over

center 6 horizontal divisions, perform b (3) below.

(6) Move time base to A HORIZ compartment.

(7) Adjust VERT SEP (1) control to align bright center trace with crt horizontal

graticule center line. If trace does not align with each graticule line within 0.5 minor

division over center 6 horizontal graticule divisions, perform b (4) below.

b. Adjustments

(1) Adjust VERT GAIN A16 R2730 (fig. 1) (fig. 8 for type R7844) for 1 trace per

division over center 6 divisions (R).

(2) Adjust VERT GAIN A13 R1730 (fig. 7) (fig. 8 for type R7844) for 1 space per

division over center 6 divisions (R).

(3) Adjust BM 2 LEFT GAIN A10 R3664 (fig. 7) (fig. 3 for type R7844) for 1 trace

per division over center 6 divisions (R)

(4) Adjust BM 1 LEFT GAIN A10 R3619 (fig. 7) (fig. 3 for type R7844) for 1 trace

per division over center 6 divisions (R).

16. Vertical High Frequency Compensation

a. Performance Check

(1) Set standardizer TEST switch to VERT or HORIZ +STEP RESP, REP RATE

switch to 1 kHz, and adjust AMPLITUDE control for 6 divisions of display on crt.

(2) Position time base controls as listed in (a) through (d) below:

TIME/DIV or DLY TIME switch to 0.5 ms.

(a)

MODE switch to AUTO.

(b)

Coupling switch to AC.

(c)

Source switch to INT.

(d)

(3) Adjust LEVEL/SLOPE variable control for stable display.

(4) Adjust vertical amplifier and time base POSITION controls to center display. If

displayed pulse does not, have flat top within 0.5 minor division, perform b (1) below.

(5) Set standardizer REP RATE switch to 1 MHz and time base sweep rate to 10 ns.

(6) Check areas of crt display at each time base sweep rate listed in table 5. If

display pulse does not have optimum square leading corners, flat tops, and peak-to-peak

aberrations are not within 2 minor divisions; perform beam 1 adjustments listed in table 5

for optimum pulse response. If necessary, repeat adjustment procedure to obtain optimum

pulse response.