Fluke/Philips, Synthesized Function Generators (PM 5139)

With these precision instruments, setting up your test signal is faster, simpler and more precise than ever before. At all times, you get a clear indication of the selected signal on the large backlit LCD display. The display gives at-a-glance readout of vital parameters such as frequency, waveform, amplitude, offset and modulation. So you're always fully informed about instrument status, selections and other essential test parameters.

To change a setting, all that's necessary is to select one of the five menu lines and press the corresponding buttons. In each case, the 'active' parameter is clearly indicated on-screen by an arrow. Then you can step through the available options, which are highlighted one-by-one on the display. These five menu lines let you make all instrument settings instantly and precisely.

All numeric values such as frequency, offset and modulation depth are set with high precision by the control knob.

Specific function keys are conveniently located in a separate field at the right of the front panel. These keys allow fast selection of function such as single or continuous burst/sweep; hold and external trigger/modulation; asymmetrical waveform with duty cycles variable from 1 to 99%; a 50% key for instant return to symmetrical waveforms, store and recall keys for up to 9 complete front-panel settings; the dial lock key to disable the control knob.

The PM 5139 has an extended waveform library offering 10 standard waveforms and 6 stored arbitrary waveforms.

Extensive modulation capabilities are a strong point of these generators. Modulation modes include AM, FM, PSK, burst, gating and linear or logarithmic frequency sweep. Full modulation capabilities are available for all types of waveforms, including arbitrary waveforms. The modulation source may be internal or external.

Both instruments have an internal modulation source, programmable over the range 10 Hz to 100 kHz, which means that for many applications there is no need for an external modulation source. External modulation sources from dc to 200 kHz can also be used.

The burst mode allows a selectable number of cycles to be created at burst trigger frequencies over a 1 MHz to 100 kHz range. The lower trigger frequencies are particularly valuable for mechanical test applications, where intervals as long as 1,000 seconds can be achieved between test cycles. All waveforms, including arbitrary, can be sent as a burst. Frequency sweep mode covers a wide 9 1/2 decade frequency range, with both linear and logarithmic sweeps and variable sweep times from 10 ms to 999 seconds. Three different modes (sweep and flyback, sweep and hold, and sweep up and down) are provided. All waveforms, including arbitrary, may be swept.

Both the PM 5138A and PM 5139 offer a versatile 'arbitrary' waveform capability, which is a powerful tool for generating custom test signals in GPIB/IEEE-488 or RS-232 system environments. Arbitrary or user-defined waveforms can be created on a PC, and then downloaded to the PM 5138A or PM 5139 via the optional GPIB/IEEE-488.2 or RS-232 interface.

A waveform captured by a Digital Storage Oscilloscope can be transferred to a PC and modified using the PM 2273 AnyWave for DOS software package. This package is a powerful tool for creating, capturing and modifying the desired signals, and transferring them quickly and easily to the function generator.

Alternatively, any desired waveform can be captured from a test system using a Fluke Digital Storage Oscilloscope, and then transferred to the PM 5138A or PM 5139 without the need for a PC. The amplitude and frequency of the captured waveform can be varied using the control knob of the function generator, and even modulation modes like AM, FM, gate, sweep and burst can be added to the captured waveform. This makes it very easy to generate a single shot in the arbitrary mode, or to sweep an arbitrary waveform.

There is no need to enter complex parameters; just select the modulation mode and parameters you want, or add a dc offset to the arbitrary waveform by selecting the dc offset function.