This paper presents the use of a programmable spectrum analyzer as a computerized "Proof of Performance" machine, particularly for proving turnkeys where accurate rapid checking of system performance is of considerable economic performance. The system is described using a computer, plotter and high speed printer. In addition, a special van for the instrument is being specially fitted with power, air conditioning, etc. The van also has a two-way radio to provide an automatic data link back to the head-end so that the computer can instruct programmable signal generators temporarily installed at the head-end to work with the whole system.