ORIGINAL: John Sohm
ORIGINAL: gsoav8r
I dont believe it will be anything higher than 2.4. Microwaves already have a hard enough time getting thru obstacles. 5ghz would only compound the issues. Anything less than 2.4 would be beneficial.
Not necessarily true. It depends on the band and what absorbs it. Seems to me that X-Rays and Gamma rays are way up there on the frequency chart and they don't have a problem going through most materials, especially humans. And no, I'm not suggesting using either of those so don't go there.
As I see it, it appears most of the individuals speaking here are speaking from conjecture and a somewhat simplistic understanding of how it all works. Statements earlier in the thread relating 2.4 GHz to light are just an example of, and please don't take this in an insulting way, the average person's ignorance of what the electromagnetic spectrum actually consists of. For a look at how it breaks down and where our systems appear in relation to it, you can visit this site for quite a bit of info even if you're not a scientist.
http://hyperphysics.phy-astr.gsu.edu/hbase/ems1.html#c1
Having been an avionics communications specialist in the USAF, I can tell you that there are many factors that affect the propagation of any type of radio wave: frequency and power level being two of the major elements. On the receiving end, you have sensitivity and selectivity as your two major players. Sensitivity is how low of a signal can be detected and selectivity is how good it can distinguish the desired signal to other similar signals. That's why with the old 72 MHz, the AMA established safe distances between fields.
Today's 2.4 GHz systems eliminate some of the selectivity issues by the bind/link process where a transmitter has a specific code associated with it that the receiver constantly monitors once it is bound/linked to the transmitter. Reminds me of the old ''I AM WELL'' signals incorporated in older equipment. Sensitivity is the next item and the more sensitive the better. These systems are limited in power, and by nature are very directional. The problem is you don't have a directional antenna to focus the beam at the plane's receiver so you're limited to an omni-directional antenna to transmit the signal in all directions. This means that a lot of radio signal is wasted going of into la-la land and not being detected by your receiver. Right of the bat you're range has been decreased. Not necessarily a bad thing considering the systems are designed to work over a relatively small range (1,000 meters or so).
So where am I going with this discussion? I guess what I'd like to say is this, there are a myriad of factors that will affect any of our radio systems and to base decisions of what is best on sheer conjecture and speculation while embracing ignorance, is counter-productive to say the least.
This thread was opened by a simple comment regarding an article regarding 2.4 GHz and blossomed into a monster with all kinds of comments to and from and at specific individuals. I don't think this should be a Jerry Springer type thread.
Any way, if I offended anyone, I apologize now and if anyone wants to learn more about the electro-magnetic spectrum that surrounds us, check out the link above.
Thanks for the chart and info but its nothing that hasnt been presented before. Plus, please dont underestimate what people here know or dont know or are capable of learning. Many if not all here have been reading up on the light spectrum and the science of it all for several years now, since 2.4 came out. I dont know it all, nor do I pretend to, but some guys here just dont have the time or desire to write a doctoral thesis on a message board.
So anyway, I agree with this; "many factors that affect the propagation of any type of radio wave: frequency and power level being two of the major elements."
Given that, historically power output from 75, 72mhz , and 2.4ghz radios have been limited to, what, 1w max?. Even lower in country's outside the US. I think I can make a fare assumption that any new frequencies allocated for RC will also be limited to 1w.
Given the limited power were allowed to transmit, I love to see any reference info that suggest 5ghz can penetrate the typical materials used in model airplanes better than 2.4g or 72mhz. (its amazing how much power is needed for x-ray generation and soft x-rays apparently wont go thru much of anything so I wont go there).
Cheers.