Hp 8557A spectrum analyzer .01 - 350 mhz 853A mainframe

Hp 8557A spectrum analyzer .01 - 350 mhz 853A mainframe

This is a used HP 8557A Spectrum Analyzer plugin with 853A mainframe. Frequency range: .01 to 350MHz. The picture show the FM radio spectrum supplied by an external antenna. This unit works great but has a few minor issues. 1. The A & B trace buttons on the mainframe are a little sticky. 2. It could use a few knobs. Handle not included.
Calibration is unknown but it appears to be within tolerance.