This is my 9cm (3.4 GHz) transverter based on the W1GHZ transverter boards driving a Stealth 3.5GHz 25 Watt Power Amplifier. As with my 2.4GHz transverter it fits perfectly into the Jaycar HB-5556 instrument case.
The transverter also includes a ADF4350 based local oscillator, Sequencer and ATF54143 preamp boards. Since the Stealth PA contains both forward and reverse power sensors it was beneficial to display this valuable information on a 20×4 line LCD display driven by the ATMega328 microprocessor on the Sequencer board.
To avoid potential IF breakthru the IF frequency can be selected between 432 or 433MHz for operation at 3.4GHz.
The following information is monitored and reported on the display:
- Forward Power
- Calculated SWR
- Power Supply Voltage
- Power Amplifier Current
This instrumentation is continuously monitored and protection is provided for High Temp, supply voltage out of range, High SWR and Overdrive protection. In my application the LO uses a OCXO which requires a short warmup period before it is on frequency, so a Oven warning is indicated for the first 5 minutes from power-on as a reminder that the frequency has not stabilized.
Work is still underway to design a suitable front panel, and more work is planned on the firmware to make it suitable for other transceiver designs. A temperature controlled fan will be installed in the future however tests for a 5 minute key down raise the temperature by only 10 degrees so it will only be require a fan for long WSJT sessions.