Charybdis

As seen in the most recent Free Flight Quarterly

2.4GHz: is it all it’s cracked up to be?

We recently received this intriguing article from Dave Horvath and invite you to read it and then join in the discussion.  

A substantial number of unexplained crashes of radio control model airplanes on 2.4GHz frequency prompted me to write this article on the so-called “interference free” radio control systems on the 2.4GHz band.          
The electromagnetic wave spectrum is subject to the immutable laws of physics.
The propagation characteristics of the 2.4GHz wavelength and the environmental effects of this frequency are more complex than on the 72MHz band. To better understand this, we have to look at the electromagnetic wave spectrum where 72MHz band is in the broadcasting region and the 2.4GHz band is in the microwave region. It is easier to see the huge difference between 72MHz and 2.4GHz frequencies when we convert 2.4 gigahertz to megahertz. Now it is 2400MHz versus 72MHz. When frequency increases, wavelength decreases. Therefore, the 2.4GHz wavelength is shorter and closer to visible light on the electromagnetic wave spectrum. Since visible light is also an electromagnetic wave, 2.4GHz wavelength behaves more like visible light and travels in straight lines until it is reflected, deflected, diffracted or absorbed. Reflection and diffraction will create interference. When parallel rays of light are reflected by a concave mirror, it greatly increases the intensity of light at the focal point. A parabolic dish antenna works the same way for a 2.4GHz electromagnetic wave. Since we cannot focus a high gain directional parabolic dish antenna between our constantly moving model airplane and our transmitter, we have to use an omnidirectional vertical antenna system which has much lower signal intensity.  

Read the rest here.

2011 SAM Champs photos from Dr. George E. Shacklett

The wind started up dramatically about 11:25 A.M. and people could see the big-assed rain cloud bearing down on the field and decided to "abandon ship" Andy Latowski "sails" his Folly back to his car .

Glenn Poole sets up to land his Speed 400 Statostreak in the breeze that was not there when he took off.
His timer gets in position to catch the model after touchdown to prevent wind damage. Despite the precaution, the "streak" tumbled and damaged one of the winglets-which he repaired this afternoon so it
is ready for the Concourse Wednesday evening.

Chuck Kime,  get's his Gollywock Electric model ready for flight Monday.
Chuck's much better half, Tina was in charge of the R/C registration and posting
operation.

Aerial view by Eut Tileston

2011 Midwest Champs Day 3

For many more photos from the third day, see slide show #3  by clicking  here.   

2011 Midwest Champs Day 2

Latowskis with 'B' Westerner for O&R .23 event

The pictures above are just a small sample of Day 2. For slide show #2 click here

2011 Midwest Champs Day 1

For slide show #1 click here .  Many more!
When you see the contest flyer, you've reached the end for day 1.

Electric Taube

Gil Morris' Taube in flight at Muncie


11/21/11 update

I proved to myself today what you preached and what the Wright brothers discovered that to turn you need to twist the wing along with the rudder. I finished mechanically linking the wing wigglers to  the rudder servo and all looked good so I headed out for Shelby this afternoon. I got half way to and spotted a nice harvested field, stopped and flew the Taube. Its turn response is good now. Still, I'm a rank amature at RC and made a hard landing. No damage but one of the bearings for the wing wiggler popped out and was lost in the dirt. So I couldn't make a second flight. I now ordered a replacement bearing from Boca. I'm hoping for an Indian summer day after the replacement bearing arrives. I don't think I can wait for next spring.

Tom, I haven't had any one contact me from the East yet.

Happy Holidays & thermals,   Gil