Selecting Frequency; Selecting Level; Selecting Modulations - Hameg HM8135 User Manual

Indroduction of the HM8135
3.7

Selecting frequency

After pressing the FREQ. key
A new value can be entered from the data keypad
modified by the digital rotary knob
context sensitive keys . For more details, refer to the pa-
5
ragraph "Setting parameters". The frequency range is 1 Hz
to 1200 MHz. The resolution is 1 Hz. If a value is entered
with a higher resolution, the instrument makes a trunca-
tion keeping 1 Hz resolution.
3.8

Selecting level

After pressing the LEVEL key
A new value of the level can be entered from the data key-
pad or modified by the digital rotary
11
of the four context sensitive keys
fer to the paragraph "Setting parameters".
The level range is:
❙ -135 dBm to +13 dBm without amplitude modulation
❙ -135 dBm to +7 dBm with amplitude modulation
❙ The resolution is 0.1 dBm.
The level displayed is specified for a load of 50 Ω. The
choice of the unit is made by the keypad
µV . For the volt unit the instrument performs a three digits
resolution according to the range (mV/µV/nV).
Caution:
If the AM modulation is activated, the instrument automatically
limits the level to +7 dBm in order to avoid an excess of the dyna-
mic of the ouput amplifier.
3.9

Selecting modulations

After pressing the MOD. key
MODULATION MENU
AM FM
MODULATION MENU
<– – FSK
The modulation type is selected by pressing one of the
four context sensitive keys
❙ AM (Amplitude modulation)
❙ FM (Frequency modulation)
❙ PM (Phase modulation)
❙ FSK (Frequency shift keying)
32
, the display shows:
9
11
or by one of the four
10
, the display shows:
9
knob or by one
10
. For more details, re-
5
dBm, mV or
11
, the display shows:
9
PM – –>
PSK GATE
corresponding to:
5
❙ PSK (Phase shift keying)
❙ GATE (Gate modulation)
The return to the previous display is possible by pressing
the PREV. key
3
After selecting the type of modulation (FM MENU), the dis-
or play shows:
The selection of the parameters for AM/FM/PM is made by
pressing one of the four context sensitive keys
ponding to:
❙ The shape of internal modulation signal
❙ The frequency of the internal modulation signal
❙ The deviation (or depth in AM)
❙ The modulation state
The return to the previous display is possible by pressing
the PREV. key
3
After selecting the SHAPE option (AM SHAPE MENU), the
display shows:
The shape of the internal modulation signal may be modi-
fied by the context sensitive keys
pointed out by a triangle .
The return to the previous menu is possible by pressing
the PREV. key
3
After selecting the Fmod option (AM MENU), the display
shows:
The frequency of the internal modulation signal may be di-
rectly changed by the numeric keypad
the digital rotary knob
sensitive keys
5
The return to the previous menu is possible by pressing
the PREV. key
3
The frequency range is:
❙ 10 Hz to 200 kHz: Sine (Step 10 Hz)
❙ 10 Hz to 20 kHz: Triangle, Square, Sawthooth (Step 10 Hz)
.
.
. The active signal is
5
.
11
or by one of the four context
10
.
.
corres-
5
or modified by