Subject to change without notice
20
O p e r a t i o n a l c h e c k
a way that the frequency response of the output
signal is not affected over the whole frequency
range of the HM8037 unit.
Operational check
General
This test will permit you to check the functions of
the HM8037 unit at certain time intervals without
using any special test equipment. To obtain the
normal operating temperature, the mainframe
with inserted module should be turned on at least
60 minutes before starting the test.
Measuring equipment required
– Oscilloscope (e.g. HM303)
– Frequency Counter (e.g. HM8021)
– Distortion Meter (e.g. HM8027)
– Digital Multimeter (e.g. HM8012)
– Resistor 600 Ω, Coaxial Cable 50 Ω HZ34
– Level Meter (Sennheiser, e.g. UPM550)
If no Sennheiser UPM550 or any similar level
meter is available for the operational check,
the corresponding tests can also be carried out
with an oscilloscope, if the obtained values are
accordingly translated. However, this will give
somewhat less precise test results.
Frequency variation of all ranges
a) HM8037 settings:
FREQUENCY 50
Hz
VARIABLE x0.1
(ccw)
or
x1.0
(cw)
AMPL. min.
(ccw)
no button pressed
b) Following the table below, the limits of all
frequency ranges can be checked.
Limits of Display
Range
VARIABLE
x0.1
VARIABLE
x1.0
50 Hz
4,4 - 4,7 Hz
57 - 60 Hz
500 Hz
44 - 47 Hz
570 - 600 Hz
5 kHz
440 - 470 Hz
5,7 - 6 kHz
50 kHz
4,4 - 4,7 kHz
56 - 60 kHz
Accuracy of digital frequency readout
a) HM8037 settings:
FREQUENCY 50
Hz
VARIABLE x0.1
(ccw)
AMPL. min.
(ccw)
no button pressed
b) Connect the SYNC. OUTPUT
to the input of
HM8021 Frequency Counter.
c) The maximum allowable deviation between
the readings of the HM8037 and the HM8021 is
±1 digit.
Output amplitude stability
a) HM8037
settings:
FREQUENCY 5
kHz
VARIABLE 1
kHz
AMPL. max.
(cw)
no button pressed
b) Connect the Level Meter to the OUTPUT 600 Ω
of the HM8037. Terminate the OUTPUT
600 Ω
with 600 Ω. Measure the output
voltage.
c) Check the output voltage within the entire fre-
quency range, using the controls FREQUENCY
and VARIABLE
.
d) The output amplitude should not vary more
than ±0.2 dB between 5 Hz and 50 kHz (reference
1 kHz)
Output attenuator function
a) HM8037
settings:
FREQUENCY 5
kHz
VARIABLE 1
kHz
AMPL. 1
V
no button pressed
b) Connect the Level Meter to OUTPUT 600 Ω
. Termi nate with 600 Ω. Adjust the output
amplitude for a reading of 1 V.
c) Firstly press one button –20 dB
, then both
buttons
simultaneously. The readings should
be 0.1 V and 10 mV (±0.2 dB) respectively.
Maximum output amplitude
a) HM8037 settings:
FREQUENCY 5
kHz
VARIABLE 1
kHz
AMPL. max.
(ccw)
no button pressed
