HP 8690A Bench Sweep Oscillator No Plug-In 8706A 8707A Compatible AS-IS

HP 8690A Bench Sweep Oscillator No Plug-In 8706A 8707A Compatible AS-IS

The HP 8690A is a benchtop sweep oscillator mainframe from Hewlett-Packard's 8690 series, designed to accept interchangeable plug-in RF modules that set the frequency range for swept-frequency RF signal generation. This particular unit has no plug-in installed and is being sold AS-IS for parts or repair. It powers on, the front-panel indicators light, and the fan runs — but it has not been tested beyond that. A sticker on the rear panel notes this unit has been modified to be compatible with the HP 8706A Control Unit and HP 8707A RF Unit Holder.

Specifications & What's Included

• Manufacturer: Hewlett-Packard (HP)
• Model: 8690A Bench Sweep Oscillator
• Plug-in module: None installed
• Power cord: Not included
• Modification: Rear sticker confirms modified for compatibility with HP 8706A Control Unit and HP 8707A RF Unit Holder
• Front panel controls: START/CW, MARKER 1 (START/CW), MARKER 2 (STOP), STOP/ΔF rotary knobs
• Front panel controls: SWEEP SELECTOR (Manual/CW/Auto/Trig), MANUAL SWEEP, VERNIER SWEEP TIME (100–10 / 1–2 /.1–.01 sec), INT SQ WAVE FREQ
• Function pushbuttons: START/STOP, ΔF, MARKER SWEEP, EXT FM, ALC, MARK 1, MARK 2, INT SQ WAVE, EXT AM
• Rear panel: BLANKING (Off/On), PWR MTR LEVEL (Off/On), MARKER and BLANKING outputs, ANODE, INPUT, PWR MTR connectors, PEN LIFT, AC POWER terminal
• Fan: Pamotor Model 400C with metal guard (rear-mounted)
• Overall dimensions: 18.5 × 16.75 × 9 inches
• Approximate weight: 50.5 lbs
• Condition: Powers on and fan spins; sold AS-IS — no further testing performed

Applications

The HP 8690 series sweep oscillator was a modular RF signal generation platform introduced by Hewlett-Packard in the late 1960s and produced through the 1970s. The mainframe houses the sweep control circuitry, power supply, and display while accepting interchangeable plug-in RF modules — each covering a different microwave or RF frequency band. This architecture allowed a single mainframe to serve across multiple frequency ranges by swapping plug-ins, making the 8690 series a versatile tool in RF and microwave labs, antenna range testing, component characterization, and radar system development. The 8690A mainframe was used alongside HP plug-ins covering bands from the low-RF range up through millimeter-wave frequencies. Today these instruments are sought by vintage test equipment collectors, microwave engineers maintaining legacy setups, and technicians looking for usable parts from the mainframe chassis.

⚠️ Shipping note: This item is heavy (~50.5 lbs) and oversized. Please contact us before purchasing to arrange a shipping quote, local pickup, or a facility viewing.