Based on the Analog Devices ADF4351 PLL chip this self-contained board can be used as a local oscillator for VHF, UHF and Microwave projects.


  • 31MHz to 4400MHz
  • Fractional-N synthesizer capable of  1KHz (or better) frequency resolution
  • 2 x RF outputs  +7dBm from 500MHz to 2GHz
  • 4 software programmable output levels at 2dB increments
  • No Tuning required
  • Frequency selection to one of 16 preset values (optional)
  • RS232 interface for  programing of frequency and power levels
  • Frequency offset for TX (optional)
  • Several reference frequency options:
    • Internal OCXO or VCXO reference
    • External Reference up to 100MHz
  • Automatically switch from internal to external frequency reference
  • CW Beacon firmware available

Having 2 high level outputs is useful for applications sharing the same LO module between 2 transverters, or driving separate RX and TX stages.


The  ZLPLL User Manual can be downloaded here:  ZLPLL User Manual


Built and tested boards are available for purchase using the following page