wsmalley

My Feedback: (6)

I'm getting ready to start building a large scale Ford Tri-motor that will be covered in .002 corrugated aluminum. I recall a fellow named Carlos Rangel used to build all aluminum models so obviously it's not a big, or insurmountable, problem. I don't know if he, or others, had some particular system to lessen problems, or if there were any. At times, I've read other threads suggesting using even the aluminum monokote was a problem. I'm not sure if whip antennas are any better in this instance over the old wire. Any data/other discussions/ideas on this?

dirtybird

My Feedback: (5)

Its not a good idea. Aluminum makes a very good shield.

davewallace

My Feedback: (29)

wsmalley,
It will most likely be a scale like flier, so the antenna should be outside the fusalage along the bottom. It would be a good idea to run it out to the tip of the stab. The side facing you on your usual direction of landing. This This should help on approach. This will help on the approach when the airframe can block the antenna. Remember FM is line of sight, for the most part. The antenna is approximatly 39" for Futaba. I don't know about JR. If you place the RX well aft, it will allow more antenna outside the fus. You should pick function over form in this case. Good luck.

Dave

JPMacG

My Feedback: (2)

Yes, make the antenna wire external and connect your receiver ground to the metal skin.

Edit.... on second thought, you may have radio problems if your metal skin is in segments and the segments are in intermittant contact... similar to noise from the throttle linkeage on an engine. Any joints in the skin should be either well connected or well insulated. Intermittant contact would be bad.

captinjohn

Get a Spectum 7 Radio System....that will be good insurance. Capt,n

FliteMetal

It appears this is a discussion of a metal (aluminum) constructed airframe and not simply a laminate covering. There are many different alloy of aluminum. These afford varying degrees of hardness and attributes which absorb or reflect radio signals, and some which permit the signal to pass through with various effects on the signal. There are no statements that can be assumed as "the" answer. Why, well most can not identify what alloy (read as composition) of the aluminum they are using on their plane.

There are severe consequences to assuming because something appears to be an X it must be an X when it could be a Y in X clothing. Horrible analogy...I know, but one which must be thought about when considering a covering material.

On the 18th of May an evaluation was conducted of Flite-Metal with three different spread spectrum 2.4 gig systems.

FYI:To answer some questions jet jocks and natural finished warbird builders might have we have posted the results of an evaluation conducted by George Maiorana and two others using his TU4.

http://004edc4.netsolhost.com/fm__spread_spectrum.htm

The range was identical regardless of where the receiver and servos sat. The systems, all of them, were still working correctly when the evaluation team stopped the evaluation with the systems in normal flight mode. The evaluation was not measuring r/f strength of the SS systems. You will note that would have required electronic measuring equipment. It was and is the only desire to observe any physical difference in the operation of the servos under the conditions the SS systems were used.

I hope this contributes to the knowledge base being expressed relative to 2.4 gig radios and their use. It is not intended to be a radio comparison, but to illustrate the findings observed during the evaluation of an application which worked correctly when a 72 khz radio system was used to control the evaluation aircraft for years in scale competition.