The HF & VHF PLO is a low noise frequency source which is comprised of two fixed frequency crystal oscillators, one HF and one VHF, and all necessary components required to phase lock these two oscillators together with a PLL loop bandwidth of ~60 Hz. This unit also includes the capability of phase locking with either an external 5 MHz or 10 MHz reference signal. When the external reference is present, the internal HF oscillator is bypassed and the internal VHF oscillator will phase lock to this external reference. The integrated assembly is packaged in a nickel plated machined brass housing (6” x 2.5” x 0.9”), suitable for vibration isolating for improved performance in dynamic environments. The typical configuration has both a 5 MHz and a 100 MHz output. An internal voltage regulator is provided for excellent power supply line rejection. Please consult the factory if you need any specifications to be modified to better suit your application.


  • HF Frequency: 5 MHz or 10 MHz, fixed
  • VHF Frequency: 50 MHz to 130 MHz, fixed
  • Low Phase Noise to -165 dBc/Hz
  • Excellent Temperature Stability
  • Low Aging rate
  • Low G-Sensitivity: 5E-10/g per axis, typ


  • Reference Frequency Source
  • System Synchronization
  • Instruments

Typical Specifications

HF & VHF PLO Typical Specs

Mechanical Drawing

HF & VHF PLO Mechanical

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