Antenna Installation

[grayfox]

Am building an RV8. 2 related questions: 1) What is the max antenna cable length recommended for the 261 X-ponder, and 2) Is there a minimum distance recommended for the proximity of the ADAHRS unit to antennas, comm. and/or X-ponder? Don't see these issues addressed in the installation instructions. From other forum threads, 8 ft. or so seems to be the max. recommended antenna cable length for the GTX-327, but don't know if this also applies to the 261. If all the electronic component installation criteria are strictly adhered to, I think I would have to conclude that the RV8 and 21st century electronics are not compatible.

 

[dynonsupport]

Page 11-10 and 11-11 of the SkyView install guide covers antenna cable lengths. You can get over 8' if you use the right cable (more expensive/delicate cable). Of course, with our transponder, you can put the whole transponder right next to the antenna in the back of the plane if you want, and just run a few small low voltage wires to it, so you have multiple options.

This issue here is not "21st century electronics" it's the fact that you loose signal in any cable and it makes the transponder weaker. Even some old vacuum tube transponder from 1972 has the same cable length issues.

Given that the transponder is a certified device and you have to have it checked by a certified shop before you can fly, don't skimp against the install instructions because the test will detect if your output power or sensitivity is too low.

The AHRS has no particular need to be any distance from antennas. The high frequency RF energy doesn't mess with any of the sensors, including the magnetometer.