FPV and the FCC

[Lupus]

Ok, so I've been trying to determine when/if a Ham License is needed for FPV in the US.

Someone please help me with this information. When do I need a Ham license to operate FPV?

The best I have been able to figure out is that it depends on the device I am using. If the device is certified by the FCC then anyone can operate it in the US. If the device is not certified by the FCC, then the operator must certify it. That can only be done by a licensed Ham operator. Is this correct?

 

[Barron.Barnett]

Depends entirely on the power levels and channels you're attempting to use for FPV.

As a note, the certification from the FCC you're looking for is Part 15, then anyone can use it, as long as they're operating within the bounds of their license. For example GMRS requires a license, however you use a Part 15 certified radio. Same can be said for LE and EMS bands, their radios are all Part 15, and you can get a Part 15 radio and program it for those frequencies, doesn't mean it's legal for you to do so. Additionally there are "public" frequencies available for use without a license with particular limits.

Most equipment you buy online is on those "open" frequencies. IE 2.4GHz, the 5.8 GHz or 900MHz. The specific frequencies (channels) are blocks in there which are publicly available with particular power limits. The precise channels used are adjacent to the HAM band so if you're a HAM and you're in a busy area you can descend into areas which should be less trafficked and use a bit more power. There is an additional caveat I haven't looked into regarding the use of the HAM band for FPV and that is the transmission limitations for HAMs. Ham radio is not to be used as a broadcast medium, there is an allocation for RC, but that doesn't call out video.

I encourage you to get your HAM because honestly it's yet another fun hobby and it will add understanding to your transmitter and receiver and help you solve problems related to such things. You don't need to do it right away or as you're first starting out. Just don't get anything that is what is referred to as "Part 97" which is certified for HAM radio use. (Commercial products still have to be certified by the FCC under Part 97 for ham radio.)

*TL;DR don't worry about getting a ham license unless you start doing long distance (technically you're supposed to stay within LOS) or you're in some place really busy and need some additional isolation for noise.

 

[Lupus]

Depends entirely on the power levels and channels you're attempting to use for FPV.

As a note, the certification from the FCC you're looking for is Part 15, then anyone can use it, as long as they're operating within the bounds of their license. For example GMRS requires a license, however you use a Part 15 certified radio. Same can be said for LE and EMS bands, their radios are all Part 15, and you can get a Part 15 radio and program it for those frequencies, doesn't mean it's legal for you to do so. Additionally there are "public" frequencies available for use without a license with particular limits.

Most equipment you buy online is on those "open" frequencies. IE 2.4GHz, the 5.8 GHz or 900MHz. The specific frequencies (channels) are blocks in there which are publicly available with particular power limits. The precise channels used are adjacent to the HAM band so if you're a HAM and you're in a busy area you can descend into areas which should be less trafficked and use a bit more power. There is an additional caveat I haven't looked into regarding the use of the HAM band for FPV and that is the transmission limitations for HAMs. Ham radio is not to be used as a broadcast medium, there is an allocation for RC, but that doesn't call out video.

I encourage you to get your HAM because honestly it's yet another fun hobby and it will add understanding to your transmitter and receiver and help you solve problems related to such things. You don't need to do it right away or as you're first starting out. Just don't get anything that is what is referred to as "Part 97" which is certified for HAM radio use. (Commercial products still have to be certified by the FCC under Part 97 for ham radio.)

*TL;DR don't worry about getting a ham license unless you start doing long distance (technically you're supposed to stay within LOS) or you're in some place really busy and need some additional isolation for noise.

Sorry, forgive my ignorance, but what is GMRS? Also, Do you happen to know the power limitations of operating in the frequencies commonly used by FPV without needing a HAM license? Such as the 900Mhz, 1.3Ghz, 2.4Ghz, and 5.8Ghz?

 

[Barron.Barnett]

GMRS is a more powerful version of FRS (Family Radio Service). GMRS is commonly used by backpackers and others who need a bit more power but don't feel like getting a HAM license. FRS basically the common radio you get at Cabela's or your sporting goods store.

As for power levels, as long as it is Part 15 it will be self bounded to the correct power level and channels. Part 97 is where you get to start having fun. What most HAMs will do anyway is get the Part 15 equipment and modify it to make it perform in the other areas you're licensed to. Also stick to omni directional antennas for the transmitter (you should anyway).

See this guide on the ISM bands. It doesn't cover 1.3, but is a good starting point and covers the basic limits.

For the most part the basic stuff you'll find online to get started shouldn't have you running out into the weeds needing to worry about all this.

 

[Lupus]

GMRS is a more powerful version of FRS (Family Radio Service). GMRS is commonly used by backpackers and others who need a bit more power but don't feel like getting a HAM license. FRS basically the common radio you get at Cabela's or your sporting goods store.

As for power levels, as long as it is Part 15 it will be self bounded to the correct power level and channels. Part 97 is where you get to start having fun. What most HAMs will do anyway is get the Part 15 equipment and modify it to make it perform in the other areas you're licensed to. Also stick to omni directional antennas for the transmitter (you should anyway).

See this guide on the ISM bands. It doesn't cover 1.3, but is a good starting point and covers the basic limits.

For the most part the basic stuff you'll find online to get started shouldn't have you running out into the weeds needing to worry about all this.

Yes, but I want to limit the number of alphabet agencies I run afoul of the best I can, I figure if I'm doing something that might be illegal, I should at least know what laws I am breaking and why.

So If I understand correctly, ALL radio equipment (transmitters and receivers) are certified by the FCC. What I need to pay attention to is if they are certified under Part 15 or Part 97. If it is Part 15 I don't need to worry about a Ham License. If it is Part 97, then I need a Ham license to use it. Is this correct?

 

[Barron.Barnett]

So If I understand correctly, ALL radio equipment (transmitters and receivers) are certified by the FCC. What I need to pay attention to is if they are certified under Part 15 or Part 97. If it is Part 15 I don't need to worry about a Ham License. If it is Part 97, then I need a Ham license to use it. Is this correct?

That's correct. Part 15 is your friend.

Given your interest in just wanting to stay in the realm of legal and understand what's going on, I highly suggest getting your HAM ticket or at least read the study guides. A decent amount of the Tech and General licenses focus on the legal aspects, not just the technical.

 

[Lupus]

That's correct. Part 15 is your friend.

Given your interest in just wanting to stay in the realm of legal and understand what's going on, I highly suggest getting your HAM ticket or at least read the study guides. A decent amount of the Tech and General licenses focus on the legal aspects, not just the technical.

Can you provide me a link to a quality online study guide that is free?

 

[makattack]

A good start: http://www.arrl.org/licensing-education-training

 

[joshuabardwell]

In 5.8 GHz, if you have an "FCC Certified" transmitter, you don't need an Amateur license. These transmitters have a permanently affixed antenna and operate at 25 mW. Their range is pretty low. Above 25 mW, you need an Amateur license.

I have never seen an FCC Certified transmitter for any frequency band other than 5.8 GHz, so I assume an Amateur license is needed to operate at all in those bands.

 

[Barron.Barnett]

Fat Sharks are 5.8 and FCC part 15. They're 250mW. But the key is, they will have a affixed antenna. (Anything with an interchangeable antenna will be part 97 because the antenna will affect the Effective Radiated Power (ERP).

I haven't seen much video for 2.4 because that's down in WiFi and controller realm and there isn't as much demand because people are just avoiding interference. I haven't seen any 2.4 part 15 transmitters so I think on that front, you'll need to go the HAM route.

 

[makattack]

Fat Sharks are 5.8 and FCC part 15. They're 250mW.

Actually, I believe the FCC certified transmitter is 25mW... and even then, apparently real-world, it's closer to 2mW according to ibcrazy/alex greve who's quoting someone else's findings:

http://fpvlab.com/forums/showthread...ied-5.8GHz-Transmitter-Testing-and-range-info

 

[severed]

www.qrz.com has the best HAM study test.

 

[RichB]

Fat Sharks are 5.8 and FCC part 15. They're 250mW. But the key is, they will have a affixed antenna. (Anything with an interchangeable antenna will be part 97 because the antenna will affect the Effective Radiated Power (ERP).

This is incorrect.

Almost all Fat SHark video transmitters are not FCC Part 15-compliant and the standard 250mW that comes with some goggles kits is definitely not. For one, 250mw is well over the 25mw limit, and also, the antenna is definitely removable.

Fat Shark does sell one specific low-power, fixed-antenna vTx/vRx combo, model number FS-2461. It's the only 5.8 vtx they make that is Part 15 compliant. It's very hard to find output specs on it, even from FatShark's own spec sheet, which omits the RF power listing.

 

[herk1]

I know people probably prefer learning on-the-cheap from free online sources, but I splurged for twenty bucks to get this book:

http://www.amazon.com/Technician-20...F8&qid=1425415185&sr=1-1&keywords=gordon+west

...and consider it money well spent. It not only gives the questions and answers for the full 426-question pool, it also explains some helpful background information on the subject of each question, often including a diagram, sketch, photo, graph, etc. It made it more interesting, easier to understand, and consequently far easier to learn quickly than it would have been to try to just memorize each question and answer. Bottom line...I aced the test!

 

[Barron.Barnett]

For one, 250mw is well over the 25mw limit, and also, the antenna is definitely removable.

Could be the site I was looking at was wrong, who knows, I'm not going to dig through my history to find it. I'd error on the side of caution anyway and thanks for the heads up, and correction. Woohoo for extra people making sure crap is right!

But FYI, from reading Part 15 the limit is 1W conducted 4W EIRP. The big killer would be if the antenna is removable you can't get Part 15 certification.

Edited to add:

I can't blame them though, getting through Part 15 is a royal pain in the ass, doubly so given the spurious emission requirements. It also isn't cheap. I suspect they have the low power limit to streamline and ease the certification process.

 

[joshuabardwell]

But FYI, from reading Part 15 the limit is 1W conducted 4W EIRP. The big killer would be if the antenna is removable you can't get Part 15

The 1 watt limit is for spread spectrum transmitters only. Analog video is not spread spectrum, which is why 25 mW is the max for unlicensed transmission in 5.8 GHz. Notice that for "Any", the limit is 50,000 uV/m @ 3 meters from the transmitter. I haven't crunched the numbers, but my inference would be that this equates to 25 mW TX power into a roughly 2 dBi(c) antenna.

EDIT: Doing a little more digging, I found the FCC database entry for the FatShark FCC Certified transmitter. The RF exposure info report contains this line: "Average Field strength = 93.88dBuV/m @3m". 50,000 uV/m is approximately equal to 94 dBuV/m, so that confirms that's the limit they're operating under.

Note, also the line that calculates transmit power and finds it to be 0.37 watts! This explains the tiny range on these devices!!! It also explains why when I converted 50,000 uV/m @ 3 meters into a mW TX power, I kept getting something like 0.4 mW, but I thought I must be wrong because these devices are supposed to be 25 mW. These devices aren't operating at 25 mW! They aren't allowed to by the FCC! But wait... I'm sure I've seen "FCC Certified" devices listed as operating at 25 mW. The plot thickens...