The Programmed Test Sources Inc. 160 is a precision frequency Generator It uses the accuracy and stability of a Frequency Standard operating at 5.0 or 10.0 MHz, either built-in or external, to produce output frequencies between 0.1 and 159.999 999 9 MHz, with up to 10 significant figures. All output frequencies are coherent with the standard frequency and reflect its stability and accuracy. Any frequency within the above band may be selected by manual dial or by remote control with resolution as fine as 0.1 Hz. The output from the levelled system is +3 to +13 dBm into 50 ohms and may be adjusted manually by the front panel control and meter or remotely by analog voltage. The Programmed Test Sources Inc. 160 is a direct frequency Synthesizer capable of providing signals for many uses requiring stable and accurate sine-wave signals with low attendant spurious outputs, low phase noise and fast transfer between selected frequencies. Typical applications include communications, spectrum analysis and surveillance, radar and automatic test systems with both narrow and wideband coverage. Manual Organization The Programmed Test Sources Inc. 160 is a complete and integrated system using up to 13 modules installed on a deck inside the instrument mainframe. All data pertaining to the total instrument as a system are presented in the System Section of this manual. This section also covers items which are integral parts of the mainframe, such as Power Supply front panel, rear panel and crystal Oscillator Modules which are mounted on the deck are covered in subsequent sections. The GPIB Interface which mounts to the rear panel, like the PE 1021 board, is treated in a separate section.