skoky v urovni RF OUT VF generatoru

[kulikus]

Zakoupil jsem ve vyprodeji RF generator od HP ESG-D2000A (E4431A)
Ma jednu necnost, pri nastavovani urovne vystupu RF OUT se signal meni znacne skokove, nikoliv podle nastaveneho udaje na dipleji.

Measurement at 277kHz and 50 ohms load (Atten Hold off, ALC on, ALC BW Normal)

Set RF Signal Levels RF OUT -measured signal amplitude i.e. Vpp/2 at screen of ociloscope
-----------------------------------------------------------------------------------------------------------------------------------
13dBm to -2,40dBm 610mV
-2,30dBm to -7,40dBm 180mV
-7,50dBm to -12,40dBm 100mV
-12,5dBm to -17,40dBm 56mV
-17,5dBm to -22,40dBm 30mV
-22,5dNm ... 16mV

Servis Agilentu (drive HP) v zahranici mne odmitl, ze to je uz nepodporovany typ a tudiz nemaji ani dily.

Na www.home.agilent.com je ke stazeni "E4428C/38C ESG Signal Generators Service Guide". Dokazal by nekdo vypomoci s opravou?