The new generator also incorporates an external frequency counter mode which utilises the full width of the display to provide up to 7 1/2 digits of resolution
The TG330 function generator, new from TTi (Thurlby Thandar Instruments), is an advanced 3MHz analogue generator with built-in sweep, amplitude modulation and simultaneous digital display of frequency and level.
The frequency range is from 5Hz up to 120MHz, and the input sensitivity is better than 50mV RMS. Accuracy is said to be typically better than ten parts in a million, and an external adjustment point allows recalibration when high accuracy is essential.
A measurement period of 0.5 or 5 seconds can be selected.
Reciprocal counting ensures high resolution regardless of input frequency, allowing, for example, mains frequency to be measured to a resolution of 0.001Hz.
In function-generator mode, the display is split into two sections. Auto-ranging reciprocal frequency measurement gives four-digit resolution with rapid update right down to 2Hz.
Accuracy is within one digit (+/-0.03% at full scale).
To maintain a fast update below 2Hz, the measurement mode is changed, resulting in three-digit resolution.
When compared to the normal fixed gate-time meters used in other products, the TG330 provides both higher accuracy and faster display update across the whole frequency range.
The output level display can be selected to show any of three values: peak-to-peak amplitude, RMS amplitude or DC offset.
The decimal point and units are changed automatically, resulting in a display of the true amplitude regardless of the attenuator setting.
The TG330 can generate sine, square, triangle, pulse and ramp waveforms with variable symmetry from 0.03Hz up to 3MHz.
A built-in sweep generator offers linear or logarithmic sweeps of 1000:1 range, with digital display of the start and stop frequencies and a sweep rate variable between 20ms and 20sec.
The main output has a maximum EMF of 20V peak-to-peak from a 50-ohm or 600-ohm source.
An amplitude vernier with a range of 20dB is combined with two switched attenuators of -20dB and -40dB to provide levels down to 2mV peak-to-peak unterminated.
Variable DC offset of +/-10V is available via a centre detent control.
An auxiliary output provides a fixed 0V to +5V level suitable for driving both TTL and CMOS loads.
AM capability is also incorporated with a choice of internal or external modulation from 0 to 100%.
The TG330 is housed in a robust ABS case with built-in tilt stand measuring 260x88x235mm. The price in the UK is £269 (plus VAT).
