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What frequencies are legal for the United States, beside 2.4ghz

jeitzman

Junior Member
#1
Does anyone know what frequencies/channels are legal in the United States that does not require a special license to operate such as 900mhz, or 5.8ghz. Obviously, 2.4ghz is since it seems everyone is using them in the world of RC. I am looking to get some FPV gear and don't want to buy something I may get fined for using.

Thanks!
 

Tritium

Amateur Extra Class K5TWM
#4
In the USA you have to get a license for all frequency's I think!

Also I don't understand WHY you can't use 2.4 with a 2.4 radio since the radios constantly hop frequency for best reception. Futaba says it should NOT be a problem but no guarantees.

Thurmond
 
Last edited:

colorex

Rotor Riot!
Mentor
#5
In the USA you have to get a license for all frequency's I think!

Also I don't understand WHY you can't use 2.4 with a 2.4 radio since the radios constantly hop frequency for best reception. Futaba says it should NOT be a problem but no guarantees.

Thurmond
I wonder that as well, I imagine that it's because the FPV uses a much wider frequency range, and it doesn't do frequency-hopping.
 

Tritium

Amateur Extra Class K5TWM
#6
I am thinking of blowing a few bucks on the 200mW 2.4 setup from HobbyKing to test my theory. My phone is 2.4 and my wireless router is 2.4 and neither causes issues with my Futaba 2.4.

Thurmond
 

colorex

Rotor Riot!
Mentor
#7
I am thinking of blowing a few bucks on the 200mW 2.4 setup from HobbyKing to test my theory. My phone is 2.4 and my wireless router is 2.4 and neither causes issues with my Futaba 2.4.

Thurmond
As I understand it, it's because all of those use different systems. Phone and WiFi use a fixed frequency, (2462MHz on channel 11 which is set by default) and use a collision detection system to transfer data (They listen until nothing else is transmitting, and then they send their data). Radio systems (Tx's) use scanning, which is similar (They scan for a free frequency and use that one).

However FPV systems don't listen or scan before transmitting. They just send out the data like they're shouting through a megaphone. Then the Rx does the same, it just takes everything it can hear, it doesn't check if it's the right thing.

So your FPV Tx could jam WiFi or phones, while phones or WiFi can mess up your video signal.
 

oagh

Senior Member
#8
ok well I dont know much , But I have a 2.4Ghz fpv " its ok" cheep! , and use a 2.4Ghz Spektrum too.I have never had or saw signal mix
.I just got a new one and it just dont work, its gray! its 900mz "hk".
But That is what i can say about the 2.4 fpv.
 

jeitzman

Junior Member
#9
I may have just found the answer to my question.

FCC Rules for Unlicensed Wireless Equipment operating in the ISM bands

The ISM radio bands were originally set aside for electromagnetic radiation produced by industrial, scientific and medical (ISM) equipment. In the early 1990's the Federal Communcations Commission (FCC) allowed using three of the ISM bands for unlicensed communication equipment. These three ISM bands are:

902 to 928 MHz
2.400 to 2.4835 GHz
5.725 to 5.875 GHz
 
#11
I may have just found the answer to my question.

FCC Rules for Unlicensed Wireless Equipment operating in the ISM bands

The ISM radio bands were originally set aside for electromagnetic radiation produced by industrial, scientific and medical (ISM) equipment. In the early 1990's the Federal Communcations Commission (FCC) allowed using three of the ISM bands for unlicensed communication equipment. These three ISM bands are:

902 to 928 MHz
2.400 to 2.4835 GHz
5.725 to 5.875 GHz


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