IC-706 mk2 Modifications
Detailed instructions for MARS transmit expansion and antenna tuner range improvement on the Icom IC-7300.
Description
Presents two distinct hardware modifications for the Icom IC-7300 transceiver, detailing the necessary steps for each. The first modification, a MARS transmit expansion, involves the physical removal of specific surface-mount diodes (D422) from the main board, enabling transmit capabilities across a broader frequency range, including out-of-band frequencies. It specifies the diode location on US versions of the IC-7300 and suggests using small diagonal cutters if a soldering iron is not preferred or available.
The second modification focuses on the internal antenna tuner, aiming to provide wider impedance matching capabilities. This involves adding a 100k ohm resistor to a designated point within the tuner circuit. The resource also briefly mentions a microphone modification for the HM219 and a general power increase, though without specific instructions for the latter two. It emphasizes safety precautions, such as disconnecting power and inspecting the work area.