VIZ WR-550B Analog Function Generator 1Hz-100kHz 120VAC Benchtop VCO DC Offset

VIZ WR-550B Analog Function Generator 1Hz-100kHz 120VAC Benchtop VCO DC Offset

The VIZ WR-550B is a benchtop analog function generator made by VIZ Manufacturing Co. of Philadelphia, Pennsylvania. It produces four selectable waveform types — sine, square, triangle, and pulse — across a frequency range of 1 Hz to 100 kHz, switched in decade steps from the front panel. A front-panel VCO (Voltage-Controlled Oscillator) input accepts an external voltage to sweep or modulate the output frequency, and a DC offset control allows the output waveform to be shifted to selectable positive or negative offset levels.

Specifications & What's Included

• Manufacturer: VIZ Mfg. Co., Philadelphia, PA 19144
• Model: WR-550B
• Part Number: 9451-404
• Type: Analog Benchtop Function Generator
• Power Input: 120 VAC, 50–60 Hz, 10 Watts
• Waveforms: Sine, Square, Triangle, Pulse — selected via front-panel FUNCTION knob
• Frequency Range: 1 Hz to 100 kHz
• Decade Ranges: 1, 10, 100, 1K, 10K, 100K Hz (switched)
• Output Level: Adjustable via front-panel LEVEL knob; output via banana jack terminals
• 4V Fixed Output: Dedicated fixed 4V output banana jacks on front panel
• DC Offset Control: Rotary switch — positions 0, −20V, −5V, +5V
• VCO Input: Front-panel terminal for external voltage-controlled frequency modulation
• INT Switch: Front-panel toggle for internal/external frequency control selection
• Output Connectors: Banana jacks (front panel, red and black)
• Country of Manufacture: United States (Made in U.S.A.)
• Included: Unit only — no accessories, cables, or manual

Applications

Analog function generators like the VIZ WR-550B were standard bench instruments in electronics labs, educational settings, and service shops from the 1970s through the 1990s. They serve as a signal source for testing amplifiers, filters, and other analog circuits — injecting a known waveform and observing how a circuit responds. The VCO input makes the WR-550B useful for basic frequency-sweep tests and voltage-controlled frequency modulation experiments, connecting to a bench oscilloscope or spectrum analyzer to observe circuit behavior across a frequency band. The selectable DC offset is handy when testing circuits that require a biased input signal. Units like this one remain practical for electronics bench work, hobbyist projects, vintage equipment repair, and educational lab use where a straightforward analog signal source is all that is needed.