Auxiliary Output; Internal Sweep; Frequency Selection - TTI TG550 Manual De Instrucciones

Amplitude
The amplitude of the MAIN OUT outputs is set by the AMPLITUDE control and the ATTENUATOR
switches. Maximum output is 20 volts peak-to-peak open-circuit, 10 volts
peak-to-peak when terminated with the outputs characteristic impedance.
The AMPLITUDE control has greater than 20dB range; the ATTENUATOR switches permit
selection of up to -60dB attenuation (both switches pressed together). Used together these
controls provide a range of 20V peak-to-peak down to 2mV peak-to-peak, or 10V peak-to-peak
down to 1mV peak-to-peak into the output's characteristic impedance.
Still greater attenuation of the 50Ω MAIN OUT can be achieved by using standard 50Ω BNC
attenuators. To maintain waveform integrity only 50Ω cable should be used and the receiving end
should be terminated with a 50Ω load.
The MAIN OUT outputs will withstand a short circuit for a period of 10 minutes at maximum output
and greater periods at lower output levels. However, damage will occur if an external voltage is
connected to the output sockets.
The 50Ω and 600Ω outputs are not independent; terminating one will affect the amplitude of the
other.
The amplitude is displayed on the right-hand side of the LCD; pressing the PK-PK/RMS button
beside the display will alternate the reading between peak-to-peak volts (Vp-p) and r.m.s. volts
(Vrms). The readout is correctly adjusted for attenuator setting and waveform shape.
The display shows open circuit voltage; the actual voltage at the socket will be half the displayed
value when the output is terminated with its characteristic impedance.
DC Offset
The DC OFFSET control has a range of ±10 volts from 50Ω/600Ω in all output modes; the control
has a centre detent for 0 volts. DC offset plus signal peak is limited to ±10V (±5V into the
characteristic output impedance); CLIP shows in the display when this limit is exceeded.
DC offset plus waveform is attenuated proportionally by the ATTENUATOR switches.
The DC offset can be displayed in place of the output amplitude by pressing the OFFSET button
beside the display. The display shows open circuit voltage offset; the actual voltage at the socket
will be half the displayed value when the output is terminated with its characteristic impedance.

Auxiliary Output

The AUX OUT output provides a fixed 0 to 5V TTL/CMOS pulse output at the same frequency,
symmetry and phase as the MAIN OUT outputs and is capable of driving 2 standard TTL loads.

Internal Sweep

With INT SWEEP selected the output of the internal sweep generator is summed with the
FREQUENCY vernier. Select LIN or LOG sweep mode; the annunciators LIN-SWP or SWP-LOG
will show in the display accordingly.

Frequency Selection

Using the FREQUENCY RANGE switches select the lowest range within which the upper sweep
limit can be set; in this way the best setting resolution and the widest sweep range can be
realised.
Sweep Limits
Turn the STOP control to minimum (fully-anticlockwise). Hold the SET START button and set the
START (lowest) frequency on the display using the FREQUENCY vernier; the START frequency
must be set first. Now release the SET START button, hold in the SET STOP button and set the
STOP (highest) frequency on the display using the STOP control; release the SET STOP button.
Note that both the FREQUENCY vernier and the STOP control have a log characteristic when
LOG mode is selected.
The sweep limits can be checked at any time by depressing the SET START or SET STOP.
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