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

Web Interface

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.

 

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.