OPERATION
3-10
First-time use
First-time users can quickly become familiar with the principles of control and display by carrying
out the following exercise, which demonstrates how to set up a typical basic signal having the
following parameters:
Carrier frequency:
100 MHz.
Output
level:
−
10 dBm.
Amplitude modulation:
30% depth at 1 kHz.
Switching on
(1) Before switching the instrument on, check that the voltage selector has been set to the value of
the power supply as described in Chapter 2, and that no signal voltage is present on the
PULSE INPUT socket.
(2) If the default display shown in Fig. 3-3 is not obtained, a previous user may have set the
instrument to switch on with one of the other user memories displayed. Before proceeding any
further you should reset this selection, see 'Power up options'. Switch off and on again.
Alternatively use the [MEM] key followed by entering 50 and terminating by pressing the
[enter] key. This will reset the instrument to the 2050T series default setting.
If the RF level units and the internal/external standard are not as shown, they can be changed
as described on Page 3-77, 'RF level units' and Page 3-71 'Selection of frequency standard'.
(3) Observe that the main menu appears on the display showing default parameters for advanced
digital modulation. The soft key label marked
[Carrier Freq.]
is highlighted (i.e. the line
bordering the label is increased in thickness to about 1 mm), which means that anything
entered at this stage will change the carrier frequency.
(4) If necessary, adjust the display for brightness and contrast, see 'UTILITIES' Page 3-69.
Changing the value of the selected parameter
If an error is made when keying in, press the soft key again and key in the correct value. If an error
message is displayed, it can be cancelled by entering a value which is within limits.
(1) Press
[Mode'n Mode]
or [UTIL]
[Mod'n Mode]
and then press the
[Single]
key. The
modulation mode will change to FM single modulation.
(2) Using the numerical key pad, enter 100 MHz by pressing keys [1], [0], [0] and the key marked
[MHz/mV/ms]. Observe that the Carrier Freq. display changes to
100.000 0000
MHz.
(3) Press
[RF level]
. The
RF level
soft key label is now highlighted.
(4) Using the numerical key pad, enter
−
10 dBm by pressing keys [
−
], [1], [0] and the key marked
[Hz/dB/rad]. Observe that the RF Level display changes to
−
10.0 dBm
.
(5) Press
[AM]
on the left-hand side of the display. The menu will now change to display AM
modulation parameters in the lower panel. The
[FM Devn.]
soft key on the right hand side of
the menu changes to
[AM depth]
and this label is now highlighted.
AM
disappears from the
left-hand side.
(6) Using the numerical key pad, enter 30% AM depth by pressing [3], [0] and [kHz/
μ
V/%].
Observe that the
AM
depth display changes to
30%
. The display will now be as in Fig. 3-4
and the selected signal will now be present at the RF OUTPUT socket.