I use only 7/16" coaxcable and connectors for the lowest possible reflection factor.

This is considerably lower then specified in the standards of Ham Radio, such as the PL259.

The main tower is supplied with the following cables:
1x   1.5/8 Coax LCF Foam-dielectric
5x   7/8 Coax LCF Air-dielectric
2x   3/8 Coax LCF Air-dielectric
1x   3.1/2-12 Coax 75ohm Air-dielectric
2x   4x6 mm2 380VAC Remote Control Cable
1x   6x2.5 mm2 220VAC Remote Control Cable
2x   12x1.5 mm2 Remote Control Cable
1x   2x2.5mm2 Remote Control Cable

Air-dielectric as well foam-dielectric (LCF 7/8") coax will be used, ranging from 3/8" up to 1.5/8" hardline.

All outer and inner conductor parts of the standard version are silver plated to achieve the best intermodulation performance. At 200MHz the 7/16" can have an average power of 3KW connected to LCF 7/8" hardline. Screening effectiveness of >128dB

The second tower (SQ4-3.5 MHz) is supplied with the following cables:
2x   7/8 Coax LCF Air-dielectric
1x   3/8 Coax LCF Air-dielectric
1x   4x6 mm2 380VAC Remote Control Cable
1x   12x1.5 mm2 Remote Control Cable
1x   2x2.5mm2 Remote Control Cable