"Carbonite" RF Opacity

Hello all,

Does anybody know if the black "carbonite" fiberglass/graphite tubing that Wildman uses causes any attenuation/blocking of RF signals?

Specifically, I'm looking to mount a BRB900 in my Wildman Dual-deploy's NC, and its' looking like somewhere down in the shoulder is the most convenient place to do so (having built mine with the "glueless NC" method Crazy Jim described in one of his many highly-informational build threads). My Wildman is from before they switched the whole airframe over to carbonite, but the NC shoulder happens to be made out of black fiberglass which may or may not be carbonite (I can't tell the difference).

I have done some testing, and it appears that the BRB900 has no more trouble finding and holding satellite lock when it's inside the NC than when it's outside, but I'm being cautious and asking anyway considering that the Wildman will be my first rocket to carry the BRB900 high enough that visual tracking isn't possible (can you say "L935"? ), and there are too many trees and hills where I live to test the transmission range over a reasonable recovery distance.

Thanks for any answers!

RedMaxFlyer said:

Does anybody know if the black "carbonite" fiberglass/graphite tubing that Wildman uses causes any attenuation/blocking of RF signals?

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I haven't noticed any attenuation at 900 MHz. I suspect that the black pigment, even if it is carbon, is such a small fraction of the total volume as to be negligible.

I have heard that the carbonite does block RF signals.

I have a BlackHawk 38 and was thinking of using the BRB 900mhz, so I inquired and a few people mentioned to not keep it in the body of the rocket. But the nosecone is RF clear.

Is the tube black carbonite or black fiberglass tube?
Gary

An email to Tim would settle all questions, but I believe the black tubes and cones Tim (aka Wildman Rocketry) sells are just black colored G12. I do not think carbon is used as the pigment.
Email Tim and get the definitive answer, that will end all speculation.

Adrian

I think Tim said they use graphite for the coloring.

I have two airframes made from the Wildman black G12, and have used both 900MHz and 433MHz transmitters in them with no noticable signal attenuation.

If I'm not mistaken, there are two different types of black tubes -- one is pigmented fiberglass, and one is graphite infused.

The former should have the same RF transparency as regular fiberglass. The regular may do some attenuation.

-Kevin

troj said:

If I'm not mistaken, there are two different types of black tubes -- one is pigmented fiberglass, and one is graphite infused.

The former should have the same RF transparency as regular fiberglass. The regular may do some attenuation.

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And they are hard to tell apart. I ran into that issue with my RW Formula 98. After prep'ing and buttoning up, had to open up the nosecone, drill a hole in the NC bulkplate and turn the tracker around so the antenna stuck out in the shoulder area. Needless to say, now I pre-test when I build a new rocket.

troj said:

If I'm not mistaken, there are two different types of black tubes -- one is pigmented fiberglass, and one is graphite infused.

The former should have the same RF transparency as regular fiberglass. The regular may do some attenuation.

Click to expand...

Interesting, I was not aware of that! If it helps the OP, my two black G12 airframes are a Blackhawk38, and one of the 2.5" diameter project packs, that Wildman offered a few years ago.

ROCKet STAR said:

Interesting, I was not aware of that! If it helps the OP, my two black G12 airframes are a Blackhawk38, and one of the 2.5" diameter project packs, that Wildman offered a few years ago.

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Both of these will be black pigmented Fiberglass.

Profusion (as seen in Proline Rocketry kits) contains a graphite infusion into the resin. This is the same as the old proline nosecones, which had a graphite infusion outer layer to give the CF appearance with RF transparency.

I would assume that both pigmented and Profusion tubing are RF transparent.

Paint can cause similar issues. OT, and just FYI.

Gerald