SECTION 6 GPIB
6-58
(4) AM modulation
• AM modulation cannot be turned on by the AM modulation setting command (AM<Numeric><AM
term>).
• Because AM modulation up and down (TEM and EAM) using the rotary knob are enabled by substituting
the step key function, the AM modulation resolution is fixed to ten percent.
• Only 1 kHz (M1) and 400 Hz (M2) can be selected as the modulation signal source when INT AM is
executed. AF (M0) cannot be selected.
• The Ext1 connector of Mod Input is assigned as the external modulation input of AM modulation.
• INT and EXT cannot be modulated together (A4 and A5).
(5) FM modulation
• FM modulation cannot be turned on using the FM deviation setting command (FM<Numeric><Freq term>).
• Even if INT FM deviation fixing (IND<Numeric><Freq term>) or EXT FM deviation fixing
(EXD<Numeric><Freq term>) is executed, when FM deviation is set (FM<Numeric><Freq term>), both INT
FM deviation and EXT FM deviation become the same FM deviation.
• When FM deviation is stepped up or down (UFM or DFM), the deviation changing amount of the MG3641A/
MG3642A becomes × 2, ÷ 2 as against × 10, ÷ 10 for the MG3633A.
• Because FM deviation up and down (TFM and EFM) using the rotary knob are enabled by substituting the step
key function, the resolution cannot be selected. The rotary knob operates in the same manner as the step key.
• Only 1 kHz (M1) or 400 Hz (M2) can be selected as the modulation signal source when INT FM is executed.
AS (MO) cannot be selected.
• The Ext2 connector of Mod Input is assigned as the external modulation input of FM modulation.
• The modulation signal polarity cannot be switched (SP23 or SP24).
(6) Modulation signal source
• Only 400 Hz (M2) and 1 kHz (M1) can be selected as the internal modulation signal source. The signal source
corresponding to AF (M0) cannot be selected.
• Only AF frequency setting using the numeric data (AF<Numeric><Freq term>) is valid. The AF frequency
cannot be set by stepping up or down (UAF or DAF) or by using the rotary knob (TAF or EAF).
• The INIT MOD DC application functions (SP30 to SP33) cannot be interchanged because the MG3641A/
MG3642A does not have an equivalent function.