13cm Transverter

2.4GHz Xvtr front panel

2.4GHz Xvtr front panel

The transverter uses a ADF4350 local oscillator and customSequencer driving a Spectrian 30W power amplifier board driven by the VK3XDK 2.4GHz transverter board.  The entire transverter fits nicely into a Jaycar HB-5556 instrument case.

Channel Selection

Channel Selection

As the NZ and Aus 13cm bandplans are not in alignment several radio amateurs have chosen to operate their equipment on different frequencies (2399/2400/2404 or 2424).   The LO synthesizer  supports 16 preset frequencies, and the VK3XDK transveter has broadband filters covering the entire 13cm band, therefore it was a simple matter of programming the correct frequencies to select a suitable band for operation.   This is to avoid the embarrassment of both parties having 13cm equipment but unable to communicate on a common frequency!

Inside View

Inside View

The Spectrian power amplifier performs well at 2.3GHz but falls off in both gain and output power before 2.4GHz.    An output power of 25W was found to be possible by adjusting the 2 matching input trimmers in the first driver stage of the amplifier module.

One future enhancement is to add a LCD display on the front panel similar to my 9cm (3.4GHz) transveter.  unfortunately the Spectrian amplifier lacks the necessary RF sensing outputs so when a display is installed in this unit instrumentation will be limited to monitoring the PA current (which adds little value given it runs in Class A with little current change at full power) and the input drive level.

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