ORIGINAL: Dave

<u>QUESTION FROM TimBle:

</u>"How is a Tx impound going to help?"

The 2.4GHz transmitter impound will help; here is why:

Range decreses as the number of clear channels decreases. Bandwidth drops each time FHSS encounters
a blocked frequency on a crowded spectrum. The crowded spectrum on the 2.4GHz band reduces the bandwidth,
increases the ever present background noise, increases the adjacent channel leakage ratio, reduces the range,
and causes overlapping. Overlapping is a direct interference.

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.

ORIGINAL: PTERODACTYL

Yaaay, doctorates are pieces of paper that you hang on the wall.
In case of an emergence a doctorate can be used to wipe your A*s but a finger works better.
Experience is what counts.
Did Einstein have a doctorate?

ORIGINAL: John Sohm


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.

ORIGINAL: Dave

<u>QUESTION FROM TimBle:

</u>''How is a Tx impound going to help?''

The 2.4GHz transmitter impound will help; here is why:

Range decreses as the number of clear channels decreases. Bandwidth drops each time FHSS encounters
a blocked frequency on a crowded spectrum. The crowded spectrum on the 2.4GHz band reduces the bandwidth,
increases the ever present background noise, increases the adjacent channel leakage ratio, reduces the range,
and causes overlapping. Overlapping is a direct interference.

ORIGINAL: cj_rumley

Are you Dave Horvath, author of the article being discussed?

ORIGINAL: Oberst


Why, only for him to be dishonest? He's only going to do what ever he can to protect the business. I doubt that he's studied electronic physics like some people I know. Heck, I doubt he even studied electronic physics 101.

Me I studied all about the 2.4GHz and different Mhz systems when I worked for AT&T. I had to attend classes in order to sell phone and landline systems and I had to a get 90% ot better to qualify in my field.

What Dave Horvath and I have written was based on knowledge, more so from Mr. Horvath. I didn't study electronic physics, but I do use common sense and good judgement from what was taught to me when I was at AT&T.

Why the RC boats work with the 2.4GHz is because the operation distance isn't like how we operate our planes. The spectum antenna is above water and isn't submerged. The hull of these boats are made of a different material and antenna is perfectly sealed.

Again it's like comparing apples to oranges.

No, the wireless phone system connects to a tower, then sent to the recieving stations tower using the 2.4GHz on the G system. The Cell phone and old pagers works under the MHz band to a towered recieving station then up to the satellite. Think of it as a triangle network. Usually they operate on MHz clusters to either Cell Sector A or B at the recieving station inorder to connect with the satellite. We stopped using Cell technology in the 1980's then went to TDMA devices at around 800MHz.

At the same time we went to TDMA the local towers then started to brodcast the MHz signals to the recieving stations tower and no longer connected to a satellite for communications speeding up the connection. When we went to CDMA, the radio signal was intensified as a result speeding up the radio waves. TDMA was even faster but had a tendancy for interference.

When the phone companies switched to a G network, G= Ghz, we no longer used the MHz for signal and went to the 2.4GHz. With the 2.4Ghz signal speed was inhanced and other applications like Wifi, text messaging and data plans could be operated at a faster transmit speed. Aka light travels faster than radio waves.


I think I can speak for Dave Horvath when I say we only are warning people so people don't crash their planes because of a faulty RC system. If we didn't care about our fellow modelers we wouldn't be waisting our time. For me and Mr. Horvath it wouldn't be right not to warn people of what we know. We are not getting paid by anyone so we are not tarnished by any corporate influances. We do it because we know it's the right thing to do. Why? Because we care. That's why you are getting faced with the truth. Anyone from Hitec, Futaba, Airtronics and JR will not tell you the truth. Why? Because they have a lot at stake financially including the AMA.

Follow the money people and use your common sense and put 2 and 2 together. Please! We are supposed to look out for one another in this hobby and not listen to those who makes a living off this hobby. They are there to sell and make money including moderators at RCU, without marketing and promotion RCU would be in trouble financially.


Pete

ORIGINAL: PTERODACTYL


Wrong!!!
Radio waves travel at the speed of light!
“Look it up.�
Makes me wonder if you really know anything at all.

Radio wave, microwave, infrared, visible light, ultraviolet, x-ray, and gamma ray are all lightwaves, the differences is there length.

Pretty sure.

ORIGINAL: John Sohm


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.

Massive gravitational force can bend light.

ORIGINAL: HighPlains

Nope, light doesn't bend.

ORIGINAL: Dave

JOHN SOHM IS ABSOLUTELY RIGHT. (Post # 304)

The 2.4GHz wavelength is directional. Since we can not 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. Since we have to use an omnidirectional antenna system,
the electromagnetic waves will scatter and diffract from objects and from the terrain around us. When the diffracted
wave reaches the receiver antenna, it is slightly lags behind the signal which traveled to the receiver antenna in a
straight line that creates interference due to the phase canceling effect.

ORIGINAL: John Sohm


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.