26
Subject to change without notice
0.2
s/div.
−
5
Hz
0.1 ms/div.
−
10kHz
0.1
s/div.
−
10
Hz
50 µs/div.
−
20kHz
50 ms/div.
−
20
Hz
20 µs/div.
−
50kHz
20 ms/div.
−
50
Hz
10 µs/div.
−
100kHz
10 ms/div.
−
100
Hz
5 µs/div.
−
200kHz
5 ms/div.
−
200
Hz
2 µs/div.
−
500kHz
2 ms/div.
−
500
Hz
1 µs/div.
−
1MHz
1 ms/div.
−
1 kHz
0.5 µs/div.
−
2MHz
0.5 ms/div.
−
2 kHz
0.2 µs/div.
−
5MHz
0.2 ms/div.
−
5 kHz
0.1 µs/div.
−
10MHz
When the
X-MAG. (x10)
button is depressed, a marker or
cycle peak will be displayed every 10div. ±5% (with
variable control in
CAL.
position; measurement in the
5µs/div.
range). The tolerance is better measurable in the
50µs/div
. range (one cycle every 1div.).
Holdoff time
The variation of the holdoff time during turning the
HOLD
OFF
knob can not be tested without opening the
instrument. However, a visual check can be made.
Without input signal, set
TIME/DIV
. and time variable
control cw, use automatic triggering. At the left hand stop
of the
HOLDOFF
knob, the trace should be bright. It
should darken remarkably at the right hand stop of the
HOLDOFF
knob.
Component Tester
After pressing the
COMP. TESTER
button, a horizontal
straight line has to appear immediately, when the
COMP.
TESTER
socket is open. The length of this trace should be
approx.
8div.
With connection of the
COMP. TESTER
socket to the ground jack in the Y-Section, a vertical
straight line with approx. 6div. height should be displayed.
The above stated measurements have some tolerances.
Trace Alignment
The CRT has an admissible angular deviation ±5° between
the X deflection plane D1-D2 and the horizontal center line
of the internal graticule. This deviation, due to tube
production tolerances (and only important after changing
the CRT), and also the influence of the earths magnetic
field, which is dependent on the instruments North
orientation, are corrected by means of the
TR
potentiometer. In general, the trace rotation range is
asymmetric. It should be checked, whether the baseline
can be adjusted somewhat sloping to
both sides
round
about the horizontal center line of the graticule. With the
HM303 in its closed case, an angle of rotation ±0.57°
(0.1div. difference in elevation per 10div. graticule length)
is sufficient for the compensation of the earths magnetic
field.
