Subject to change without notice
20
F u n c t i o n s
Operational check
This test should help verify, at certain intervals,
the functions of HM8030-6. In order to reach
thermal balance, the module and the basic instru-
ment, in its case, must be energized for at least
60 minutes before the test begins.
Measuring equipment required
20MHz Oscilloscope: HM303 or similar
HZ22 50 Ω Through-Termination or equivalent
HM8012 Digital Multimeter or similar
HM8040 Adjustable DC voltage source
(max. 30V) or similar
HM8021 Frequency Counter or similar
Frequency variation
The adjustment range of the FREQUENCy knob
must in any case overlap the selected decade on
both sides by min. 2%.
Amplitude stability
Setting: (6)
(4)
(3)
(12)
1k max max
Connect oscilloscope to output
. Use a 50 Ω
through termination. Set oscilloscope to DC
coupling. Adjust signal height to 6 div. Check all
frequency ranges with and . The signal height
should not vary by more than 0.2 div.
frequency in the entire frequency range of the
HM 8030-6. The stop frequency can be indepen-
dently set the same way to a frequency which is
a maximum of 2 decades appart from the start
frequency. Push the SWEEP push button again
(STOP-LED lights). The max. freqency deviation is
given by the difference between start and stop fre-
qencies. This relationship may reach a factor 100.
The sweep time can be set when TIME is selected
by means of the SWEEP button (TIME-LED lights).
The sweep starts immediately when TIME is selec-
ted and can be set during operation. Time is set by
means of the FREQUENCy potentiometer and
ranges from 20ms to 15s. For external frequency
modulation please refer to “FM input“.
2
nd
FM input
If an AC voltage is applied to the FM input on the
rear panel of the HM8001-2, the generator fre-
quency is being frequency modulated in time and
according to the signal shape of this AC voltage.
The frequency deviation depends on the amplitude
of the AC voltage.
If a positive DC voltage is applied to the FM input
on the rear panel of the HM8001-2, the generator
frequency increases and is accordingly displayed.
A negative DC voltage reduces the frequency. The
frequency displacement depends on the value and
polarity of the DC voltage U and on the FREQUEN-
Cy settings. The frequency delivered at 0V input
may be freely selected.
Computation:
N = N
0
+ A × U or U = (N-N
0
) : A
N
0
= digit display at 0V
N = digit display applied voltage U,
U = ± voltage at the FM input.
A = approx. 1050 (digits per volt),
It should be noted that only the displayed digits
are valid; the decimal point is not taken into
consideration (e.g. 100.0
v
1000 digit). The max.
frequency (10 MHz) cannot and “000” should not
be exceeded. Any zeros preceding the decimal
point are dropped. The stability of the frequency
set depends essentially on the stability of the
applied voltage U.
The frequency change is linear a function of the
voltage U.
In 10 MHz range factor A is approx.
2500!
Examples:
N
0
= 500 (Hz) (range 5k) , U = +2V:
N = 500 + 1050 · 2 = 2600
N
0
= 3000 (kHz) (range 10M), U = -2V:
N = 3000 + 1050 · (-2) = 900
N
0
= 50.0 (Hz) (range 500), N = 190.0 (Hz):
U = (1900 – 500) : 1050 = 1,33V
Sawtooth output
For correct triggering during sweep the HM8030-6
features a sawtooth ouptput. This signal is avai-
lable at the rear panel of HM8001-2.
