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All Signal Hound devices are calibrated to better-than-box specs during production. However, if you require a signed calibration certificate with a printed packet of calibration data, you will need to select it below:

Warranty length *

Our standard warranty is for a 2-year time period. An extended warranty is available up to a total of five years (2-year warranty plus 3 additional years). Extended warranties are calculated at 6% of the product cost, per year.

The VSG25A hardware features a 12-bit I/Q baseband arbitrary waveform generator which can be clocked at virtually any frequency from 54 kHz to 180 MHz, and includes a 4096×16 bit pattern buffer for built-in or custom modulation.

Read This! The VSG25A is named Microwave Journal’s MVP for the month of May, 2015! Read the full article (1.8 MB PDF).

The included software automatically generates:

  • CW: 100 MHz to 2.5 GHz, -40 dBm to +10 dBm
    • Unspecified operation down to 80 MHz, or -70 dBm to +13 dBm
  • AM / FM: 30 Hz to 40 MHz modulation rates, sine, triangle, square, ramp
  • Pulse: 6 ns to 25 ms width, 12 ns to 1 second period
  • Multi-tone: Up to 1023 tones with optional center notch
    • Use random phase + notch for Noise Power Ratio testing
    • Use parabolic phase for best signal / noise
    • 4k to 45M symbols per second
    • Optional raised cosine, root raised cosine filtering
    • Up to 512 symbols, streamed continuously in a loop
    • Binary symbol editor features 1-click insertion of PN7 / PN9 sequences
  • QAM: QAM-16, QAM-64, QAM-256 (same features as PSK)
  • ASK / FSK: 4k to 45M symbols per second
    • Optional Gaussian filtering
    • Up to 512 symbols, streamed continuously in a loop
  • Sweep
  • Arbitrary Custom Modulation
    • Load a CSV file with I and Q values, specify center frequency, amplitude, pattern length (up to 2048), pattern period (up to 65535), and clock rate.

The VSG25A vector signal generator does have some limitations. The pattern buffer is small and cannot be upgraded. There is no reconstruction filter on the I/Q baseband, resulting in out-of-band spurious signals, and there is a single 2.7 GHz low pass filter on the RF output, so 3rd harmonics below 3.6 GHz may need to be filtered externally. If these are not show-stoppers for you, the VSG25A is an unbeatable value.

7 reviews for VSG25A Vector Signal Generator

  1. Avatar

    Nestor V. (verified owner)

    works great. software interface could use some improvements.

  2. Avatar


    this is good product its economy price

  3. Avatar

    Andrew Lenton

    It is a shame it does not go down to 2 MHZ, any chance? I also need to cover the lower VHF bands 30-100, VHF FM starts at 88 MHz!

    • Avatar

      Cory Allen

      Hi Andrew. We don’t have plans to go any lower on the VSG25. This may be overkill for your application, but our VSG60 is capable of going to 30MHz (despite the specification only going to 50MHz).

  4. Avatar

    Frederick Mak

    We bought 2 of these and for a product with this pricing and performance, I would love to rate above 5 stars if that’s possible. Thank you for having such a great product!

    • Avatar

      Cory Allen

      Thanks for the support and a great review!

  5. Avatar


    I am wondering if VSG25A can achieve AM modulation whilst running a frequency sweep between 100 to 1000MHz!

    • Clint Burgess

      Clint Burgess

      Thank you for the question. These modulations can be performed independently but cannot be combined in this way. Be in touch if we can answer anything else related to VSG25A functionality.

  6. Avatar

    Luciano Colin

    Hello, would it be possible for VSG25A to generate π/4 – QPSK signal around 159 MHz?

    • Andrew


      Hi Luciano,

      Yes, the VSG25 is capable of this. You can create a pi/4-DQPSK signal with symbol rate between 4kHz-45MHz, with a center frequency between 100MHz-2.5GHz. Let us know if you have additional questions.

  7. Avatar

    Luciano Colin

    Hello Andrew, one doubt. Is it possible to create a message in the buffer which is formed by different modulation schemes? To be more precise, is it possible to generate VDES (ITU R-REC-M.2092-1-202202-E) messages with VSG25?
    Many thanks.

    • Avatar

      Cory Allen

      Yes, you can customize the bit patterns in the software – this is indeed possible. One thing – to expedite questions like this in the future, please submit them in our VSG forums. Thanks!

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Device dimensions


Weight.28 lbs (.13 kg)
Dimensions5.5" x 2.25" x 1.04" (13.5 x 5.7 x 2.6 cm)

Product-in-packaging dimensions


Weight.96 lbs (.44 kg)
Dimensions9.25" x 5.44" x 3.13" (23.5 x 13.8 x 7.95 cm)


VSG25 Software Installer_(x86) v. 1.0.9

  • Software installer for the VSG25 vector signal generator user interface.
  • Includes software, drivers, and manuals.
  • For Windows 11/10/8/7 systems.
  • Release Notes


VSG25 Software Development Kit

  • Includes VSG25 programming interface for direct device control.
  • Programming example for C++.
  • For 32 and 64-bit Windows operating systems.


All manuals are included in the software installer. For direct links to individual manuals, see below.