10 GHz, state of play
Over the past few months I acquired some parts needed to complete the Eyal Gal transverter. I had to build the filter placed just after the TX mixer that has been done by using 15mm pipe caps. The local oscillator feeds the two mixers (TX and RX) with a 6dB directional coupler and a buffer amplifier.
The sequencer has been made with a simple circuit (IK5ZWU) and adapted to the Eyal Gal. The signal “TX Inhibit” is used to avoid any RF coming from the FT-817 during the changeover. In RX the Eyal Gal’s amplifier is disabled and his gain is set to the minimum.
The “ALC” signal simply sets the gain level of the output amplifier. With the FT817 set to maximum output power on 432 MHz (4 Watts) the trimmer R11 is regulated to obtain little more than 1 Watt. By lowering the FT817 driving power, the 10G power will be lowered to 600, 250 and 50 mW
Up to now I had only one SSB QSO, with IK0EQJ, and I discovered an annoying difference of some kHz between the RX and TX frequency. Probably I have to separate the power supply of the local oscillator from the transverter.