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Do we need an amateur radio license to operate on 5.8Ghz at 4W (EIRP)?

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Do we need an amateur radio license to operate on 5.8Ghz at 4W (EIRP)?

I`m lost. If I look here I can transmit without license on 5.8ghz up to 4 Watt (EIRP)

http://www.answers.com/topic/ism-band-technology

but it is on ISM band. Does it mean I can transmit video and audio?

What is the maximum power allow on 5.8ghz without license? Can you show me a link ?

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I mean what is the maximum power allow without license to transmit video on 5.8ghz?

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The RF power levels that web site shows is for digitally modulated devices (i.e., frequency hopping, direct sequence, etc.) which is a special license-free class. Our analog video systems do not qualify.

Canada and the USA have harmonized spectrum rules, so we can simply review the USA's FCC Part 15 regulations. But before we do that, here are some useful things to know.

1. On RF devices like our analog video devices, the raw RF Power is NOT observed by the RF rules and any reference to RF power is meaningless. The rules only observe the Radiated energy of the combined transmitter and its specifically approved antenna.

2. The regulations are concerned with more than just the radiated RF levels of the main operating frequency. The device needs to be tested for a variety of criteria (for example, radiated harmonics are very important).

3. And that is why NOTHING is license-free unless it specifically has a valid FCC registration number printed on it (or printed in the manual if the device is too small for a label). It is the registration number, and only the registration number, that allows license-free use. No other criteria will allow license-free operation in the USA.

In a nutshell, item #3 is the most important and everything else is meaningless. So, anyone operating in North America, that says (for example) that they don't need a license because the video transmitter is low power, is operating illegally because they would need a RF device identified with an assigned registration number to do that.

But to specifically answer your RF Power question, the Part 15 rules say this (non-digital applications):




Section 15.249 Operation within the bands 902 - 928 MHz, 2400 - 2483.5 MHz, 5725 - 5875 MHz,
and 24.0 - 24.25 GHz.

(a) The field strength of emissions from intentional radiators operated within these frequency bands shall comply with the following:

Fundamental......... Field Strength......... Field Strength
Frequency........... of Fundamental......... of Harmonics
.................... (millivolts/meter).... (microvolts/meter)
__________________________________________________________________
902 - 928 MHz........... 50....................... 500
2400 - 2483.5 MHz....... 50....................... 500
5725 - 5875 MHz......... 50....................... 500
24.0 - 24.25 GHz........ 250..................... 2500
__________________________________________________________________


( b ) Field strength limits are specified at a distance of 3 meters.
( c ) Emissions radiated outside of the specified frequency bands, except for harmonics, shall be attenuated by at least 50 dB below the level of the fundamental or to the general radiated emission limits in
Section 15.209, whichever is the lesser attenuation.
( d ) As shown in Section 15.35, for frequencies above 1000 MHz, the above field strength limits are based on average limits. However, the peak field strength of any emission shall not exceed the maximum permitted average limits specified above by more than 20 dB under any condition of modulation.




Note the absence of "RF Power" in the rules.

So, at 900MHz - 5.8GHz a North American license-free device is allowed 50mV/meter at 3 meters of radiated field strength. Translating this to an equivalent RF power when a 0dBi antenna is used, would be about 0.5 milliwatts ERP (0.0005 watts). If the antenna has gain then the RF power would need to be less in order to be compliant with the regulations. So, approved transmitters will include the allowed antenna; any optional accessory antennas would need to be listed in the submitted test data.

But all of this is a don't care if you have a ham radio license and operate under those rules. I know you have your license, so you are good to go if you simply follow the permissions granted in your license class.

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It is rare that we see an advise on the website that this tx need a ham license. Only few FPV site have the advise, but many big store like Supercircuit do not advise the tx need a special license. If a custmer buy it how he can know it need a special license to operate?

Most custumer probably buy high power transmitter and use them without license, probably not even knowing it need a license. Do you think it is true?

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If a customer buy it how he can know it need a special license to operate?

That used to be an issue that I could empathize with. But really, does any serious FPV'er not know a ham license is needed? This discussion comes up all the time at forums like rcgroups and it appears that very few care about it. Honestly, from what I see while on the road, no one is observing long established driving rules, so it is no wonder they care less about this.

If we continue to ignore the regulations it may come to haunt our hobby one day. So, follow your ham ticket's permissions. :)

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It is rare that we see an advise on the website that this tx need a ham license. Only few FPV site have the advise, but many big store like Supercircuit do not advise the tx need a special license. If a custmer buy it how he can know it need a special license to operate?

Most custumer probably buy high power transmitter and use them without license, probably not even knowing it need a license. Do you think it is true?

Have you checked out Hobby Kings website? they offer multi channel .9 GHZ and 2.4 GHZ up to 1000 M/w for 2.4 and 1500 M/w on .9 . No mention of ham license nor the one channel only rule for the USA and Canada. My old .9 has 4 and 2.4 has eight channel dip switches. Suppose we want to fly together on separate frequencies? Humm Just FYI

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They are based in China, so couldn't care less... why put some warning that might lower sales for people who are the other side of the world?

Plus, if they did that, they'd actually have to put a 2-page warning that lists all the different regulations in every country of the world, not just US as it's different everywhere... would make no sense.

However they shouldn't be writing things like on their 8 channel 900MHz/100mW TX that says "legal in most countries"... actually it pretty much isn't legal anywhere in the world, not even in the US with ham license as only one channel is useable there, and there shouldn't be a way to switch to another.

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