Low-cost Function Generator with full digitalcontrol.
The TG420, new from TTi (Thurlby Thandar Instruments), is a
low-cost 20 MHz sweep/function generator with full
microprocessor-based digital control and an RS232 interface.
Unlike most lower-cost function generators, which use a technology
that enables them to operate up to no more than a few megahertz,
the TG420 uses an alternative technology which retains its waveform
quality right up to 20 MHz.
The heart of the TG420 is a microprocessor which provides complete
control of all the generator functions. A 'spin wheel' rotary encoder
is used to change values which are displayed on the backlit
Digital control enables full programmability via 30 set-ups stored
within the instrument or via the RS232 interface.
When improved frequency accuracy is required, the TG420 can
be placed into 'frequency lock' mode. The generator frequency is
then continuously compared with an accurate reference and
The TG420 has a built-in generator for linear or logarithmic sweeps.
Start and stop frequencies are independently adjustable, and sweep
rate can be set between 2O ms and 20 sec per sweep. An external
modulation input provides for AM or FM modulation at up to 100%
from DC up to 50 kHz, or for externally controlled sweeps.
The TG420 provides a main output with a maximum EMF of
20 V peak-to-peak from a 50-ohm source. Amplitude control of
26 dB is combined with two -20 dB switched attenuators to provide
levels down to 10 mV peak-to-peak. Variable DC offset of ±10 V
is available. An auxiliary output provides a fixed 0 to +5 V level
suitable for driving both TTL and CMOS loads.
An RS232 interface is included which accepts remote control
commands and can be used with the optional Windows based
PC-420 software. This provides graphical control of the generator
including control simulation, configuration files, and automatic
The TG420 costs £249 (plus VAT) in the UK.
For more information, please contact :-
Thurlby Thandar Instruments