Stanford Research Systems SR844, User Manual

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Shift Functions 3-43
SR844 RF Lock-In Amplifier
CLEAR ONE [Shift–
Start/ Step]
This key sequence discards the stored Rel Configurations and Values
at the
current frequency.
STORE
R[dBm]
θ
[Shift–
Store XY] Performs Auto Phase and Auto Offset on R[dBm] and stores the
R[dBm] offset and reference phase as R
θ
Rel Values at the current
scan frequency. R[dBm] and
θ
displays are offset to zero. Any
previously stored R
θ
Rel Values are replaced. If the current
measurement configuration differs from the previously stored
configuration, it is also replaced. Previously stored XY Rel Values
are discarded if they were stored with a measurement configuration
which differs from the current one.
The R[dBm]
θθθθ
indicator turns on indicating that R
θ
Rel Values are
stored for this scan frequency.
2F Mode [Shift–Source]
This key sequence toggles 2F harmonic detection. 2F mode is shown
by the indicator above the
EXTERNAL
and
INTERNAL
indicators.
2F detection is available for both External and Internal Reference
modes. In both cases, the displayed frequency is the 2F detection
frequency. The frequency of the REF OUT signal is at F or half of the
displayed detection frequency. In External mode, the frequencies of
REF IN and REF OUT are both F.
Important!
The 2F detection frequency is limited to 50 kHz to 200 MHz. This
corresponds to a REF IN and REF OUT frequency range of 25 kHz to
100 MHz.
The absolute phase in 2F mode is not specified. However, the relative
phase accuracy generally applies.