The PM 5134 is an easy-to-use yet sophisticated function generator embodying a wide range of facilities in a single instrument. It produces sine, square and triangle wave forms as well as positive or negative pulses and DC. The duty cycle is variable between 10% and 90%. The 1mHz to 20MHz frequency range is selected by means of a 10-position rotary switch with an overriding coarse/fine adjustment. This fine adjustment, combined with the 3 1/2 digit LED display, gives an immediate, highly accurate readout of the selected frequency. Setting up procedures are thus very much simplified compared with the traditional dial setting and any human errors (e.g. paralax) are eliminated. In addition, the 3 1/2 digit display can be used to monitor the open-circuit output voltage. Also, when used in the sweep mode, the start, stop and run frequencies are indicated by separate LEDs. Moreover, an error warning lamp automatically indicates any incompatible setting-up conditions. _C The high , nominal accuracy of ±2% ±1 digit, can be further improved to ±5 x 10 by operating the instrument in the crystal-control mode. This facility is useful, for example, for identical repetitive measurements requiring high accuracy, or for narrow band filter tests. The X—TAL AM mode offers a stable carrier wave with defined frequency. One particular application is when using a 10.7 MHz carrier frequency to check that the discriminator section of a radio receiver is suppressing the AM wave form. The continuously variable 20Vpp max output (10Vpp for pulses) is available at the front panel socket; there is a pushbutton choice of 600Ω or 50Ω output impedance. The output attenuation is selectable in any combination of 3-6-10-20dB pushbuttons with an overriding continuous 20dB control. Sweep facilities include single and continuous operation. The single sweep can be triggered either manually, or electronically from an external source. The sweep period is continuously adjustable between 5ms and 100s. The START and STOP frequencies are non-interactive and can be set independently of each other. A HOLD facility allows a sweep to be stopped at any desired frequency — useful for checking phenomena occurring during a sweep — by means of a pushbutton. An interrupted sweep is continued by simply releasing the HOLD button. If required a sweep can be reset to the start frequency using the RESET pushbutton. The generator offers an internally or externally controlled burst or single-cycle signal. The start/stop phase is continuously adjustable between -90° and +90°. The internal AM is adjustable between 0 and 100% modulation depth. The modulation frequency can be set over a wide range from 10mHz to 20kHz. The AM facility can be used with crystal control, if desired. External AM inputs in the range from DC to 20kHz can be applied via a rear-mounted BNC- socket. The internal FM can be continuously adjusted between zero and ±10% frequency deviation. Other input/output facilities available on the rear panel include a TTL output and pen lift control. The design of the PM 5134 has resulted in a clean, simple front panel layout which allows the operator to become quickly familiar with all control functions. Its overall versatility makes it suitable for a wide range of applications within research, design or educational organisations. The instrument occupies minimal bench space.