GP1665W - Programmable 50 MHz Waveform Synthesizer - Wavetek 178 Compatible

GP1665W – Programmable 50 MHz Waveform Synthesizer

Programmable 50 MHz Waveform Synthesizer - Wavetek 178 Compatible
  • 100% Form-Fit-Function compatibility with Wavetek 178 Programmable Waveform Synthesizer
  • Generates sine, square, triangle, ramps, haversine, havertriangles, AM (sine), and DC waveforms
  • Synthesized to 8 digits in all modes
  • Frequency range from 1 µHz to 50 MHz
  • Phaselocking allows GP1665W to operate as a variphase generator
  • Trigger, gate, or burst generator
  • Logarithmic or lineal sweep generator
  • Phase- or amplitude-modulation
  • National Stock Number: 6625-01-550-0545
  • AFMETCAL procedure available


The GP1665W is a direct drop-in replacement solution for the obsolete Wavetek 178 waveform synthesizer. The GP1665W is a programmable instrument capable of generating sine, square, triangle, ramps, pulse, and haverwaves from 1 µHz to 50 MHz. The firmware is customized for the Wavetek 178 command set. Test applications using the Wavetek 178 require no code modification when upgrading to the GP1665W.


Automatic Test Equipment (ATE)
Component Analysis
Communication Signals
Process Control


The GP1665W can operate in a trigger, gate, or burst generator mode at levels up to 20 Vpk-pk. It is synthesized to 8 digits in all modes. The main generator produces the sine and square waves, as well as triangles, ramps, pulses, and haverwaves at reduced frequencies.

The internal sweep generator varies the main generator frequency linearly or logarithmically between start and stop frequencies. It operates in triggered, gated, hold at start, and hold at stop modes. It also has 10 programmable frequency markers to show critical frequencies within the sweep. The sweep generator can trigger the main generator to produce pulses with a 10 µs to 10 min. repetition rate and 5 µs to 5 pulse width.

The GP1665W can be phase locked by using an external reference input to lock the reference source. This allows the synthesizer to operate as a variphase generator with phase offset in 0.01° increments.

Output level into a 50 Ω load from 1 mV to 20 Vpk-pk with 3 digits resolution. DC offset can be programmed to vary the base line ±10 V.

Additionally, the GP1665W allows two external inputs to phase- amplitude-modulate it. If it is phase modulated, the main generator varies ±360° at frequencies above 500 kHz. With amplitude modulation, the output can be modulated up to 200%.


GP1665WR : Programmable Waveform Synthesizer – Wavetek 178 Compatible with Rack Mount


Operating Modes
Continuous Generator runs continuously.
Triggered Generator is quiescent until triggered by an external signal, internal sweep signal, GPIB, or manual trigger, then it generates one cycle at the selected frequency.
Gated Same as triggered except generator oscillates for the duration of the gate signal plus the remainder of the waveform in progress.
Triggered Haverwave Same as triggered mode except output is sine or triangle waveform starting at -90° or +90°.
Gated Haverwave Same as gated mode except output is a sine or triangle waveform starting at -90° or +90°.
Triggered Burst Same as triggered mode except the number of cycles output for each trigger input is selectable from 1 to 65,536 (2 16) counts.
Triggered Haverwave Burst Same as triggered burst except output is a sine or triangle waveform starting at -90° or +90°.
Frequency Sweep Output can be swept by internal sweep generator.
Frequency Range
Low end frequency for all waveforms is 1 µHZ.
Continuous Mode:

to 50 MHz in sine, square, and AM sine modes
to 500 kHz in triangle mode
to 20 kHz in ramp mode

All Triggered Gated and Burst Modes:

to 200 kHz in sine, square, triangle, and AM sine
to 20 kHz in ramp mode
Main Output 20 Vpk-pk into 50 Ω load. Combined amplitude/DC offset waveforms not to exceed ±10 V peak into 50 Ω. Output voltage into an open circuit is double indicated voltage when a voltage less than ±5 V peak is selected.
Amplitude Conversion Permits entry and display of amplitude for all waveforms in units Vrms, Vpk-pk and dBm.
Frequency Resolution 8 digits or 1 µHZ.
Accuracy Better than 0.0005% of program setting, ±0.01 µHZ.
Stability Long term: ±51 x 10-6/mo.
Temperature: ±51.2 x 10-7/°C.
Signal to Phase-Noise Greater than 46 dB in a 30 kHz band centered on carrier, but excluding a ±1 Hz band around the carrier.
Spurious 60 dBc or 30 µV , whichever is greater, 1 µHZ to 500 kHz
50 dBc or 30 µV , whichever is greater, 500 kHz to 50 MHz.
Amplitude Characteristics
Range and Accuracy 10.02 TO 20 vPk-Pk: ±1% ±20 mV
1.01 TO 10 vPk-Pk: ±1% ±10 mV
0.101 TO 1 vPk-Pk: ±3% ±2 mV
10.1 TO 100 mvPk-Pk: ±4% ±100 µV
1 TO 10 mvPk-Pk: ±5% ±20 µV
Note: DC offset range is 0 to ±10 VDC. Specified for 1 kHz sine wave or for DC output into a precision 0.1% 50 Ω load
Resolution 3 digits <= 10.0 Vpk-pk, 4 digit (20 mV) <10 Vpk-pk
DC Offset ±1% of setting ±40 mV (worst case)
Note: Amplitude and DC offset share the output attenuator.
Frequency Response ±1% for 1 µHZ to 20 kHz
±3% for 20 kHZ to 500 kHz
±7% for 500 kHZ to 25 MHz
±15% for 25 MHZ to 50 MHz
Offset Characteristics
Phase Offset Output phase may be changed from ±1,000 revolutions (±360,000 degrees) in 0.01 degree resolution steps up to 500 kHz and 0.1 degree resolution steps above 500 kHz.
DC Offset and DC Voltage Output 0 to ± 10VDC into 50Ω Output voltage is double into open circuit when voltage is less than ±5 VDC is selected.
Waveform Characteristics
Sine Distortion -55 dB to 50 kHz
-40 dB to 500 kHz
-30 dB to 50 MHz
Specified for 1 Vrms (2.83 Vpk-pk) sine wave
Square Rise and Fall Times Less than 8 ns, 1.01 to 10 Vpk-pk
Less than 10 ns, greater than 10 Vpk-pk
Square Aberrations Less than 5% of pk-pk voltage
Period 10 µs to 600s
4 digits or 10 µs resolution (Control: Sweep Time); jitter <2% of pulse width
Width 5 µs to 500,000s (>5 days)
8 digits (Control: Main Frequency); <0.05% jitter
Note: Width is usable to 1 µs
Sweep Mode
Sweep Generator Sweep generator is fully synthesized any may be used independently or for frequency sweeping and triggering the main generator. Frequency sweep may be selected linear or logarithmic, and up or down. Sweep may be triggered, interrupted with hold, and continued with resume. Triggered, gated, and burst are permitted during sweep.
Continuous Sweep Sweep generator sawtooth runs continuously
Triggered Sweep Incoming trigger causes a single sweep and resets to the start frequency
Twiggered Sweep/Triggered Reset As in triggered sweep, but sweep holds at stop frequency until subsequent trigger returns frequency to start frequency
Sweep Time 0.01 to 600 sec, 4 digit or 10 µS resolution
Output 0 to approximately +5V ramp synthesized to 2,000 steps per sweep. 600 O output impedance.
Frequenct Marker Output TTL levels. One of the ten preset markers can be selected. Output is low whent then main generator frequency is below marker frequency; output is high when above.
Maximum Sweep Range Low Band: 1 µHZ to 500 kHz
High Band: 5 kHz to 50 mHz
Minumum Sweep Range Linear: Low Band: 20 mHz per 1 s of sweep time
High Band: 2 Hz
Log: In addition to the above, any start and stop
frequencies with ratio greater than 2.
Sweep Resolution Frequency Resolution (Start, Stop, Hold, Markers): 8 digits or 1 µHZ
Sweep Frequency Update: Every 5 µS (lin and log)
Log Slope Updates: Every 2 ms
Auxillary Outputs
TTL and TTL Sync At generator frequency, 50 Ω source impedance, 50% duty cycle, <5 ns transition time.
Reference Output 10 MHz, 1 Vpk-pk sine, 50 Ω source impedance
Sweep Ramp See Sweep Generator
Frequency Marker See Sweep Generator
Trigger A TTL level transition can trigger or gate both the main generator and/or internal sweep generator. Triggering slope up or down is selectable.
Reference An external 0.5 V to 10 Vpk-pk sine or pulse clock of ±5 ppm or better stability and accuracy automatically locks the internal reference. External clock may be 1, 2, 3…9 or 10 MHz. Input impedance is 1 kO.
Amplitude Modulation Rates from DC to 10 MHz minimum. Input impedance is 600 O. 5 Vpk-pk input gives 100% modulation. Main output halved with no modulation. 200% modulation permitted. Sync output not affected by modulation.
Phase Modulation Rates from DC to 10 kHz minimum. Input impedance is 10 kO . ±5 V input delivers approximately ±360° shift. Output deviation is ÷100 for main output frequencies 500 kHz and below.
Interface Fully compatible with Wavetek 178
Memory Up to 5 complete instrument settings can be stored and recalled from volatile (RAM) memory. Settings may be modified or deleted.
Power Requirements 100-240 V selectable, 50 VA max
Weight 5 Kg
Dimensions 13.0 cm (5.25”) H x 21.2 cm (8.3”) W x 40 cm (15.75”)L
Operating Temperature 0° C to 50° C
Humidity To 95% RH, 0° C to 40° C
Connectors Rear panel connectors optional
Rack Mount Optional
AFMETCAL Procedure 33K3-4-3583
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