Tektronix RG501 Ramp Generator

Back to Tek TM500 Series Summary Page

BAMA RG501 Free Manual Download Site
Bitsavers RG501 Free Manual Download Site

Quick Specifications / Photos
Detailed Specifications
Operating Instructions
Misc. Part Numbers

Samples of e-Bay Prices
Tektronix Catalog CostLow BidHigh Bidaverage
$175 (1973-new)
$295 (1977)
$540 (1982)
$30.00 8/23/01 #1628146591 calibrat1
$11.50 3/12/02 #1711779173 sales(astglobal)
$38.51 1/22/03 #3108223883 bpba (works) (5 bids $25 start)
$35.00 5/10/05 #7513221530 telephone-trading-post (3 bids $10 start) (tested w/ scope)
$29.99 1/2/06 #7575086535 outback6 (1 bid) (untested)
$23.50 (+$11 ship) 11/15/06 #120052340803 cmw-1 (5 bids $12.99 start) (untested ??)
$76.00 (+~$12 ship) 9/26/07 #200154442510 greatresults (9 bids $0.95 start) (tested)
$21.50 (+ $11.59 ship) 12/1/07 #330193106692 56mouth56 (2 bids $19.99 start) (untested)
$86.78 (+$16.30 ship) 12/29/07 #270198384741 rjk-equip (10 bids $19 start) (tested functional)
$37.00 (+$13 ship) 7/30/09 #360173659342 gws_inc (4 bids $9.99 start) (sold as is-testing not mentioned)

  • 10 μs to 10 s Ramp Duration
  • Plus or Minus Output
  • 10-V Amplitude
  • Scope-type Trigger Functions
  • Gate Out, TTL Compatible



    The RG 501 Ramp Generator produces an adjustable 10 V ramp, either positive-going or negative-going, with selectable and variable durations from 10 s to 10 μs. A TTL-compatible gate signal coincident with the ramp duration is provided at the front panel.

    The RG 501 has a full set of oscilloscope-type triggering controls providing normal or automatic triggering, slope and level selection, and triggers from three sources: line, internal, or external via a front panel BNC connector.

    The RG501 is ideally suited to sweep VCF or VCO inputs of most function generators. The gate output signal provides for synchronizing the swept oscillator to the sweeper input. A natural application of the RG501 would be to pair it with another plug-in member of the TM500 series rack. The FG501 is an example of a function generator that can be swept over a 1000:1 range.

    The RG 501 operates in a TEKTRONIX TM 500 Series Power Module only. It is completely compatible with other members of the system in terms of signal interconnections.


    Function Generators

    The RG 501 ramp is ideally suited to sweep the VCF or VCO inputs of most function generators. Selectable ramp polarity provides for sweeping frequencies up or down. Variable ramp amplitude and duration provide for controlling the range and rate of the frequency sweep. The RG 501 gate out signal provides for synchronizing the sweep oscillator to the sweeper input.

    A natural application of the RG 501 would be to pair it with another member ot the TM 500 Series, the FG 501 Function Generator. The FG 501 frequency can be swept over a 1000:1 range with the RG 501's 0 to 10 V linear ramp. The output of the FG 501 can then be used to test the response characteristics of frequency sensitive circuits.

    X-Y Monitors

    The RG 501 can be used as a source for X- and Y-axis signals to convert an X-Y display to a Y-T display. Set the RG 501 to AUTO TRIG and use the RAMP OUT signal to drive the X-axis. A positive-going ramp will sweep most CRT displays from left to right. Vary the RAMP AMPLITUDE for the desired sweep length. The 10-volt range of the RG 501 should give a full-screen scan on just about any X-Y CRT display.

    Use the GATE OUT signal, which is coincident with the RAMP OUT, to drive the Z-axis. The gate's +3V amplitude is sufficient to unblank most CRT's and provide a usable intensity level.

    If the event to be displayed in the Y-axis meets the triggering requirements, it can be used to externally trigger the RG 501 producing a stable display when the LEVEL control is correctly set.

    Using time marks and a graticule for the CRT display, a calibrated 3% time base can be generated.

    Pulse Generators

    The RG 501 can be used as a source for externally triggering pulse generators, such as the TM 500 Series PG 501 Pulse Generator. For applications where the pulse output period is controlled by the period of the triggering signal, such as the PG 501's External Trigger Mode, the fast-rising GATE OUT signal from the RG 501 can provide periods ranging from about 20 μs (50 kHz) to about 10 s (0.1 Hz) at voltage levels sufficient to trigger and reset the PG 501.

    For applications where the pulse output period and duration are dependent on the period and duration of the triggering signal, such as the PG 501's External Duration Mode, the RG 501 can provide gating periods ranging from about 20 μs to about 10 s and gate durations fro 10 μs, within 3%, to 1 s, within 3%, and to about 11 s using the uncalibrated DURATION MULTIPLIER.

    The RG 501 RAMP OUT signal can be used as a calibrated delay trigger source for external trigger circuits having fixed trigger thresholds within the range of the RAMP AMPLITUDE control.


    DurationRange, 1 s to 10 μs;
    Multiplier, X1 to at least X10:
    Accuracy, within 3% with MLTIPLIER set to 1 (MULTIPLIER not calibrated).
    LinearityWithin 2% of a straight-line plot.
    AmplitudeRange, variable from 50 mV or less to at least 10 V, either polarity;
    DC Level Between Ramps, 0 V within 20 mV;
    Driving Capability, 3 kΩ minimum, 300 pF maximum.
    DURATIONCoincident with ramp
    AmplitudeTTL-compatible, 0 V within 100 mV, to +3 V, within 0.8 V;
    Risetime, 100 ns or less;
    Falltime, 100 ns or less.
    Source Impedance160 Ω, within 5%
    LevelRange, at least ±1 V.
    AutoSweep circuit free-runs in absence of an adequate internal or external signal or in the presence of a signal running at 20 Hz or less.
    ExternalSensitivity, at least 200 mV peak-to-peak;
    Response, DC to at least 100 kHz;
    Input Impedance, 10 kΩ to 20 kΩ, diode-protected;
    Max Input Voltage, 50 V (DC + peak AC)
    InternalSame as External except that the trigger input is via the rear interface.
    LineTriggers at the line frequency

    above excerpts from 1977 TM 500 brochure and RG 501 RAMP GENERATOR Instruction Manual


    Controls and Connectors

    RAMP DURATION Pushbuttons -- Select six ranges of ramp duration. Calibrated when DURATION MULTIPLIER is at 1

    DURATION MULTIPLIER Control -- Varies the RAMP DURATION from X1 (calibrated) at the cw end of rotation to about X11 at the ccw end. Control uncalibrated in between.

    TRIGGERING Pushbuttons -- Pushbuttons select triggering mode, slope and trigger source.
    AUTO TRIG (button in) mode produces recurrent ramps of selected RAMP DURATIONS at rates determined by holdoff time. The AUTO TRIG mode prevails (1) in the absence of an adequate triggering signal or (2) in the presence of an adequate triggering signal but with the LEVEL control misadjusted or (3) in the presence of an adequate triggering signal running at 20 Hz or less.
    NORM (Auto Trig button out) mode requires an adequate triggering signal and adjustment of the LEVEL control to produce a signal at the RAMP OUT connector.
    Slope button in (=) or out (-) determines whether ramps will be initiated on the positive-going or negative-going portions of the triggering signal.
    INT button pushed in selects internal trigger source input via rear interface connections.
    LINE button pushed in selects line-frequency voltage as the trigger signal source.
    EXT button pushed in selects the front panel BNC input EXT IN as the trigger signal source.

    LEVEL Control -- Varies the amplitude point on the triggering signal at which the triggering window is placed.

    RAMP AMPLITUDE Control -- Varies peak amplitude of the ramp from about 50 mV at the ccw end to greater than 10 V at the cw end.

    POLARITY Pushbutton -- Selects positive-going ramps (button in) or negative-going ramps (button out).
    above excerpt from AF 501 BANDPASS FILTER Instruction Manual

    1-2366-1428-00Knob: (Duration Multiplier)
    1-3366-0494-00Knob:Gray (Ramp Amplitude)
    1-4366-0494-00Knob:Gray (Level)
    1-5366-1257-26Push Button:Gray--AUTO TRIG
    1-6366-1257-28Push Button:Gray--+SLOPE
    1-7366-1402-27Push Button:Gray--INT
    1-8366-1257-23Push Button:Gray--LINE
    1-9366-1257-24Push Button:Gray--EXT
    1-10366-1402-26Push Button:Gray--+ (Polarity)
    1-11366-1257-60Push Button:Gray--10us
    1-12366-1257-50Push Button:Gray--100us
    1-13366-1257-49Push Button:Gray--1ms
    1-14366-1257-48Push Button:Gray--10ms
    1-15366-1257-47Push Button:Gray--100ms
    1-16366-1402-28Push Button:Gray--1 SEC
    R27311-1368-00Res,Var,Nonwir:5K Ohm,20%,1W (A-B 73A1G040L502M) (Level)
    R85311-1369-00Res,Var,Nonww:Pnl,1K Ohm,1W (A-B 12M887) (Ramp Amplitude)
    R56311-1365-00Res,Var,Nonwir:50K Ohm,20%,1W (A-B 11M164) (Duration Multiplier)
    R56311-1470-00Res,Var,Nonir:Pnl,50K Ohm,1W (A-B 11M055) (Duration Multiplier)
    1-37260-1437-00Switch, Push:5 STA,Non-Short(Auto,slope,int,line,ext)
    1-38260-1208-00Switch, Push DPDT (Polarity)
    1-39260-1438-00Switch, Push:6 STA,Interlock,Non-Short (1us-1sec)
    U30155-0056-00Microcircuit,DI:Sweep Control (Tektronix)
    U50155-0042-03Microcircuit,DI:Miller Integrator (Tektronix)
    U100156-0067-00Microcircuit,LI:Operational Amplifier (Tektronix)
    U110156-0277-00Microcircuit,LI:Voltage Regulator (LM340T-5)
    U120156-0067-00Microcircuit,LI:Operational Amplifier (Tektronix)