Tektronix FG 501A 2MHz Function Generator TM500 Plug-In Sine Triangle Square

Tektronix FG 501A 2MHz Function Generator TM500 Plug-In Sine Triangle Square

The Tektronix FG 501A is a 2 MHz function generator plug-in module designed for use in Tektronix TM500 series modular mainframes. It generates sine, triangle, and square waveforms across an exceptionally wide frequency range — from 0.002 Hz up to 2 MHz — with a single BNC output channel. The front panel provides a large frequency dial with multiplier switch, waveform selection buttons, symmetry control, offset adjust, and amplitude output knob, along with dedicated TRIG OUT and VCF INPUT BNC connectors for triggering and voltage-controlled frequency applications.

Specifications & What's Included

• Frequency Range: 0.002 Hz to 2 MHz
• Output Waveforms: Sine, Triangle, Square
• Output: 1 channel, BNC connector
• Trigger Output: TRIG OUT BNC connector
• VCF Input: VCF INPUT BNC connector (voltage-controlled frequency)
• Symmetry/Offset control: front-panel VAR SYMM and OFFSET DC AMPL controls
• Amplitude output control: front-panel OUTPUT knob
• Form Factor: TM500 series plug-in module (card-edge rear connector)
• Manufactured: United States
• Module only — TM500 series mainframe not included

Applications

The FG 501A was part of Tektronix's TM500 modular instrument system, introduced in the early 1970s, which allowed technicians to build customized bench setups by combining plug-in modules — function generators, oscilloscopes, counters, power supplies, and more — in a shared mainframe chassis. This modular philosophy was widely adopted across test and measurement labs, service depots, universities, and R&D facilities through the 1970s and 1980s. The FG 501A specifically filled the role of a general-purpose analog waveform source: its wide frequency sweep (sub-millihertz to 2 MHz) and three waveform types made it useful for audio circuit characterization, filter testing, servo system analysis, signal injection, and general analog electronics development. The VCF input enables frequency sweeping via an external control voltage, which was commonly used in swept-frequency measurements and automated test setups. Compatible TM500 mainframes include the TM501, TM503, TM504, TM506, and TM515, among others. This is a classic piece of analog test infrastructure from the era when modular bench instruments were standard practice.