December 2023

0-2 GHz All-band, All-mode Transmit & Receive Converter

Converts any HF radio to any amateur band - 136 kHz through 1296 MHz better than 1 Hz frequency accuracy

 


Features

  • Simultaneously converts a 20 MHz block from HF to and from anywhere in 0-2 GHz
  • 2200m through 23 cm Amateur band operation, converts LF through UHF
  • Fully coherent and fully synchronous conversions
  • Full duplex - independent conversions, simultaneous receive and transmit 
  • ~10 mW output for ~1 mW input on transmit
  • Approximately 10/25 dB conversion gain on receive, preamp off/on
  • Can be paired with an external  PA/preamp to produce higher power
  • Supports either GNSS or 10 MHz discipline frequency reference
  • Typically better than .1 ppb,  <<1 Hz at 1296 MHz
  • WiFi web Interface, monitored and controlled by way of a web browser
  • Configurable User Clock, may be used to phase lock a user's HF radio or as shack frequency reference
  •  Front Connections:
  • SMA: GPS Antenna or External 10 MHz reference
  • 0-2 GHz receive input
  • 0-2 GHz transmit output

    •  Rear Connections:

  • 10-30 MHz Receive IF output
  • 10-30 MHz Transmit IF input
  • Filtered, amplified and isolated GNSS output for other devices
  • Selectable bypassed HF antenna Input
  • SMA:User Clock output  2 kHz to 160 MHz
  • 2.1mm barrel connector for power
  • external supply voltage 7-32V @ approximately 5W
  • Double-sided, 4-layer, silk-screen PCBs

    • Web Interface

    How It Works

    The block diagram above describes a frequency converter where a range of frequencies is converted  to another by an offset. This is what usual amateur receive and transmit converters do. For example, a 146 +- 2 MHz range of frequencies in the 2m band may be converted to 28 MHz in the 10m band for receiving on HF equipment. SImilarly a 2m transmitting converter may convert a 28 MHz signal applied to a 146 MHz output on the  2m band. Complex modulation types are maintained but simply offset to and from an HF band.

    Simple conversion techniques involve an offsetting oscillator and a mixer.  For typical passive mixers, conversion is symmetrical so it can be performed either lower frequency to higher or the other way around. But the conversion/mixing process is nonlinear and generates more than a single output. There are image frequency, harmonic mixing and harmonics of the signal and of the local oscillator (LO) present at the output. For simple systems filtering, balance and other steps need to be taken to assure a single frequency is converted without generation of unwanted signals.

    This transverter uses a triple conversion technique to remove many of the unwanted signals that are present in a simple conversion process. It does this by generating an intermediate frequency which is above the highest range of desired frequencies  along with a low pass filter to remove image frequency, LO and other unwanted components. It offers the ability to quickly tune one of the conversion LOs to produce a desired output over a wide range of offsets.

    For this transverter the goal is to convert the operation of an amateur radio HF transceiver or transmitter/receiver combination to and from any frequency from near-DC to 2 GHz. The triple conversion method shown along with a disciplined LO system which is common to both transmit and receive conversion is used to generate accurate copies of an incoming/receive signal to an HF intermediate frequency (IF) between 10-30 MHz while a symmetrical process is used to simultaneously convert an HF transmitting IF to the same range.

    The following plot is a vector network analyzer (VNA) measurement of the transmit side of the transverter in action. Because without extra effort the VNA cannot measure frequency converted signals, that is, the stimulus and sensed signal must be at the same frequency as the detected signal within the VNA, to make this measurement the transverter was tuned to produce no net frequency conversion; the offsetting frequency was set to zero. With this done, both the receive and transmit conversion paths can be measured. The measurement was taken with 30 dB of extra attenuation and  shows the transmit converter flatness and about 14 dB of conversion gain where the output power was about +13 dBm or 20 mW.


    Phase noise performance of the three LO's give a good approximation of end performance. All LO's are referenced to the same clock
    so within their PLL bandwidth of ~ 60 kHz have cancellation. The lower and upper plots give an idea of VHF, -105 dBm/Hz and
    2 GHz, -85 dBm/Hz performance near the carrier, respectively:

     


    Transverter in use to convert an Icom IC7300 for use on 70cm NBFM. A Transceiver Interface conditions the Icom input/output
    for use with the transverter and is powered from the Aux Connector.  The User output from the Transverter is set to 41.344 MHz
    and provides GNSSDO master clocking for the IC7300. This produces sub-ppb precision to the 0-2 GHz input and outputs from the Transverter.



    In this  short video clip video clip a TRXduo HFSDR is used directly with the Transverter while controlled by Thetis from HPSDR
    to create an all band, all mode, disciplined amateur station. The IC7300 Transverter system above is transmitting USB on 1296.100000 MHz.
    These are entirely separate systems actually on-air, each with its own biconical antenna separated about 25 meters.
    Although the TRX is fully capable of external disciplined clocking so fully phaselocked by its TRansverter, in this particular recording
    it is operating from its internal clock so may be off frequency a few Hz.




    Here is  a KiwiSDR receiving a broad spectrum showing VHF HDTV Channel 9 OTA from 100 km distant.
    Notice the pilot carrier nominally at 186.309440559 MHz which measure within 5 milli-Hz of that after an hour's sample with fldigi.