1-10
X, Y, R,
θθθθ
and dBm
SR844 RF Lock-In Amplifier
6
Connect the signal generator output to the
SR844 SIGNAL IN connector with a BNC
cable.
The CH1 and CH2 readings should both vary
between positive and negative values in a correlated
fashion that reflects the changing relative phase
between the two instruments.
7
Adjust the signal generator frequency if
necessary to better match the signal generator
frequency to the SR844.
The extent of adjustment should be less than 10 Hz.
8
Adjust the signal generator frequency in steps
of 1 Hz (or less) until the CH1 and CH2
readings oscillate with a period of a few
seconds.
The CH1 and CH2 display bargraphs should now
oscillate slowly.
9
Press CH1
Display
once to select R [V].
R is the signal amplitude and is independent of
reference phase ( R=
√
(x
2
+y
2
) ). The reading of R
does not oscillate.
10
Press CH1
Display
to select R [dBm].
The R[dBm] display on CH1 should read within a
few dB of 0 dBm (0.224 Vrms) depending upon the
amplitude setting of the signal generator.
11
Adjust the signal generator amplitude to half
the original amplitude (100 mVrms, –6 dBm,
or 300 mVpp).
The R[dBm] display should drop by 6 dBm.
12
Press CH1
Display
several times until R [V]
is selected once again.
The
Display
key cycles through the available
choices.
13
Press CH2
Display
to select
θ
.
CH2 now shows the signal phase
θ
. The phase is
changing linearly with a rate equal to the frequency
difference between the signal generator and the
SR844. The readout and bargraph ramp linearly and
smoothly from –180
°
to +180
°
(or vice-versa) once
each period. When displaying
θ
, the bargraph on the
CH2 display is scaled from -180
°
(extreme left) to
+180
°
(extreme right).
14
Press the
Source
key (above REF OUT).
Switch the SR844 to External Reference Mode.
Since there is no external reference input connected
yet, the Reference Display should read about
19 kHz (the internal oscillator pulls to its lowest
frequency) and the red
OUT OF RANGE
and
UNLOCK
indicators should be lit.
Содержание SR844
Страница 10: ...viii SR844 RF Lock In Amplifier...
Страница 12: ...1 2 Getting Started SR844 RF Lock In Amplifier...
Страница 32: ...2 2 SR844 Basics SR844 RF Lock In Amplifier...
Страница 60: ...3 2 Operation SR844 RF Lock In Amplifier...
Страница 102: ...3 44 Shift Functions SR844 RF Lock In Amplifier...
Страница 108: ...4 6 Index of Commands SR844 RF Lock In Amplifier...
Страница 144: ...4 42 Example Program SR844 RF Lock In Amplifier...
Страница 146: ...5 2 Performance Tests SR844 RF Lock In Amplifier...
Страница 150: ...5 6 Performance Tests SR844 RF Lock In Amplifier...
Страница 156: ...5 12 Performance Tests SR844 RF Lock In Amplifier...
Страница 158: ...5 14 Performance Tests SR844 RF Lock In Amplifier...
Страница 162: ...5 18 Performance Tests SR844 RF Lock In Amplifier...
Страница 166: ...5 22 SR844 Test Record SR844 RF Lock In Amplifier...
Страница 168: ...6 2 Circuitry Parts Lists and Schematics SR844 RF Lock In Amplifier...
Страница 246: ...Parts Lists SR844 RF Lock In Amplifier 6 80 Schematic Diagrams...