Does carbon Kevlar interference with transmitter without external antennas?

[Pwb201]

What does everybody think? Rigging cordon Kevlar hull, not hatch MHz 44" mystic, using spectrum marine rx. I've heard people say there is interference because of the material of hull between tx and rx?

[norbique]

Carbon WILL interfere. It's like metal in your boat (it even conducts electricity) and will make radio interference. Extend your antenna outside the hull.

[cuppa]

Carbon WILL interfere. It's like metal in your boat (it even conducts electricity) and will make radio interference. Extend your antenna outside the hull.

yep - you will definitely be better off running the antenna outside of the hull.

[Pwb201]

Than guys..

[JIM MARCUM]

Potential antenna reception interference? Carbon fiber-yes. Kevlar-no. JIM

Note: As long as it dosen't wrap around the antenna or block the TX/RX signal, epoxy & Carbon fiber are great. Reinforcing inner hull buttoms, motor mounts etc. are not an issue. JIM

[Pwb201]

So Jim? What exactly are you saying?

[Pwb201]

Just got off phone with spectrum tech, says I can use the "carbon" rx which is an air rx. I didn't ask him if the air rx will "bind" and work with land/marine tx...this sux

[JIM MARCUM]

What I was trying to say is that carbon fiber placed between your TX and RX - "line of sight" - may cause radio interferance. Looking at your hull, if all of the hull is carbon fiber ("wraped around the internal RX antenna") you may have reception issues. The reason is carbon is a semi-conductive element, and conductive materials (steel, iron, & many metals) can or may block radio frequencies. With FE boats, you may get "glitches" or total shutdown. With gas or nitro boats loss of reception can leave your throttle wide open & out of control. I've crashed my fair of Gas & nitro boats. Most RX used today have a failsafe built in & will shut down if the signal is lost. No runaways or out of control crashes.

As to using an airplane RX, don't do it. Other than the rules not allowing it (for the TX at least), there are a lot of problems. Both modern surface & air TX & RXs' operate in the Giga HZ radio spectrum - and both would have the same receptions problems with carbon fiber blocking the TX signal.

If your FE boat hull is 100% carbon fiber and the RX antenna mounted inside the hull you have a problem. If that's the case, I would just mount at least 3" of the antenna on the top of the hull so the TX & RX can "see" each other. That is true even if you have a plastic/fiberglass hull with the antenna mounted inside. If the angle of your boat causes the TX to RX signal to be blocked (by a motor, SS motor mounts, batts) you can have intermittent reception problems. JIM

[Pwb201]

Thanx Jim for the thorough answer ton my question. Really didnt want to put antenna externally but sounds like I have no choice. Boats too pricey to take any chances..

[cuppa]

You will be much better off running the antenna externally. Carbon fibre is an electrical conductor and a carbon fibre hull has the potential to form a a Faraday cage: http://en.wikipedia.org/wiki/Faraday_cage and thus form a barrier to radio signals.

[norbique]

You will be much better off running the antenna externally. Carbon fibre is an electrical conductor and a carbon fibre hull has the potential to form a a Faraday cage: http://en.wikipedia.org/wiki/Faraday_cage and thus form a barrier to radio signals.

Exactly!

[JIM MARCUM]

Check this out: http://arxiv.org/pdf/hep-ex/0504036v1.pdf

Electrical Conductivity of Carbon Fiber
Carbon fiber with ultra-high modulus (1000 GPa) also has low resistivity (100
cm) [10]. These materials are characterized by particularly high conductivity
at high frequency with associated design issues.

So, high frequency 2.4 GHz radio waves would be very effected by the high conductivity of carbon fiber hulls. JIM