Centrad GF 266, Instruction Manual

Page: 26 / 52

- 26 -
4000 4 319 _EN - 02/09
ENGLISH
A second press selects the attenuation which is switchable to 3 positions using the thumbwheel switch: 0 dB, - 20 dB
and -40 dB.
By selecting -20dB and pressing again button [11], it is possible to adjust the signal from 0.20V to 2.00V in 10mV
steps.
By selecting -40dB and pressing again button [11], it is possible to adjust the signal from 0.020V to 0.200V in 1mV
steps.
Note: The displayed voltage level is for an open-loop condition, i.e. without output load.
DC OFFSET VOLTAGE ADJUSTMENT ( OFFSET )
Fig. 8
Pressing the Offset button [12] selects offset adjustment. The offset voltage is adjusted using the thumbwheel
switch [17] from -10 V to +10 V.
As soon as the offset voltage becomes different from 0 V, the
Offset LED [7] lights up to indicate decalibration.
In the decalibrated Offset mode, pressing the Valid/Calibr button [15] returns to the calibrated mode (0 V, LED [7]
off).
Note: The displayed voltage level is for an open-loop condition, i.e. without output load.
Reminder:
The output impedance (internal resistance) of the GF 266 is 50
Ω . If the output is loaded with 50 Ω , the internal resistance
and load form a divide-by-2 circuit. Therefore the voltage will vary from -5 V to +5 V.
The displayed
Level and Offset levels will be divided by 2 .
Notes: The amplifier output peak voltage is ±10 V. Beyond, the amplifier saturates.
To obtain a correct output signal, the sum of the
Level and Offset (absolute) must necessarily be less than or equal
to 10 V.
DUTY CYCLE ADJUSTMENT ( % DUTY ) Fig. 9
The duty cycle adjustment is active at the 50
Ω
output only when the square signal (SQUARE) is selected. It is
always active at the TTL output, whatever the signal present at the 50 Ω output.
To access to this function, simply press the Duty button [12], and adjust using the thumbwheel switch [17] from
10 to 90% or from 90 to 10%.
As soon as the duty cycle becomes different from 50/50, LED [8] lights up to indicate decalibration.
In the decalibrated Duty mode, pressing the
Valid/Calibr button [15] returns to the calibrated mode (50/50).
LED [8] off.
0
T i m e ( s )
+ 1 1 V
T i m e ( s )
V o u t ( V )
- 1 1 V
O f f s e t + s i g n a l
> - 1 0 V ( s a t u r a t i o n )
O f f s e t + s i g n a l
> + 1 0 V ( s a t u r a t i o n )
0
T i m e ( s )
+ 1 0 V
+ 5 V
O f f s e t + s i g n a l < ± 1 0 V
( n o s a t u r a t i o n )
V o u t ( V )
V o u t ( V )
0
T i m e ( s )
T o n
P é r i o d
V o u t ( V )
D u t y : 1 0 % o n 9 0 % o f f
0
T i m e ( s )
T o n
P é r i o d
V o u t ( V )
D u t y : 5 0 % o n 5 0 % o f f
0
T i m e ( s )
T o n
P é r i o d
V o u t ( V )
D u t y : 9 0 % o n 1 0 % o f f
T o f f
T o f f
0
T e m p s ( s )
V o u t ( V )
+ 1 0 V
+ 5 V
0
T e m p s ( s )
V o u t ( V )
+ 1 0 V
+ 5 V
O f f s e t : 5 V
A t t e n : 0 d B S i g n a l : ± 5 V
0
T e m p s ( s )
V o u t ( V )
+ 1 0 V
+ 5 V
O f f s e t : 5 V
A t t e n : - 2 0 d B S i g n a l : ± 0 . 5 V
O f f s e t : 5 V
A t t e n : - 4 0 d B S i g n a l : ± 0 . 0 5 V
Fig. 7
Fig. 8
Fig. 9