Frequency Legality

[Wingman04]

I live in Central Pa and have been wondering if 900 mhz is legal in my area. I want the high penetration and slightly longer range because we have a TON of trees and some buildings around my yard/airstrip.

Also I was wondering the range of the most popular frequencies with a 3dbi antenna.

 

[makattack]

Are you a ham/amateur radio license holder/operator? That's pretty much what you would need for operating FPV equipment in that band. It's not hard to achieve and only furthers your hobby if you go for it:

https://en.wikipedia.org/wiki/33-centimeter_band#Current_amateur_uses
http://www.arrl.org/getting-licensed

 

[PsyBorg]

If you are new to the hobby or old like me trust me.. that walk to go pick up a crashed quad can be a long and lonely journey that gets old really fast. Long range may look cool right up to that point you have to start walking or in some cases driving to go find yer gear.

 

[Wingman04]

Are you a ham/amateur radio license holder/operator? That's pretty much what you would need for operating FPV equipment in that band. It's not hard to achieve and only furthers your hobby if you go for it:

https://en.wikipedia.org/wiki/33-centimeter_band#Current_amateur_uses
http://www.arrl.org/getting-licensed

I don't have a HAM licence. What other frequencies can I use without a HAM licence? From what I understood in FT's video, you don't need a HAM, or at least under 100 mW. Perhaps I just misunderstood them.

 

[PsyBorg]

Check the links Makattack dropped in his last post. The information you need is in those for all the specifics. 25 mw F.C.C. approved is the only legal fpv transmitters without a HAM in the US so not even all 25 mw tx are lawful. As far as alternate frequencies I am unaware of any designated for FPV use other then the 5,8 ghz, 2.4 ghz and 900mhz bands and the delegated channels with in those bands.

 

[Wingman04]

So any of those three bands are legal without a HAM licence as long as I use a 25mW system? Or is that just 5.8?

Also, do I need the same manufacture Rx as the Tx?

Yes, I know, I knowledgely challanged when it comes to FPV.

 

[makattack]

Well, technically, equipment that is FCC certified and doesn't require a ham license will operate at those power levels, or lower, it's complicated by the fact that even some non-licensed equipment (not FCC certified) are out there, so technically, if you aren't a ham operator, you can't be using unlicensed equipment. A ham operator can use unlicensed, experimental, DIY equipment, so that's another reason for getting your license if you wish to be operating legally.

Also, while there are 5.8GHz FPV equipment that is FCC certified and can be operated without a license, there are far fewer 2.4GHz systems (and I believe they cost much more than the 5.8GHz systems).

I don't know of any 900MHz FPV systems that are FCC certified, but can't say for sure they don't exist.

In theory, manufacturers can make devices in those bands that are FCC approved, by the nature of them being ISM bands, but it's just a question of who has taken the trouble to.

Here's a great FT article that covers the above in more detail and accuracy:
https://www.flitetest.com/articles/fpv-the-fcc-and-amateur-radio-makes-three

Here's a great series of educational videos made by IBCrazy/Alex Greves, who's arguably one of the earliest advocate and developer of FPV equipment:

https://stoneblueairlines.com/success-and-fpv

 

[PsyBorg]

The whole thing about F.C.C certified gear is the 25 mw is measured at the amplifiers and not the radiated power. So that 25 mw is in actuality only about 5 mw actual output. That is totally useless for any fpv other then a tiny whoop and even then it will be insanely short range. This is why no company bothers to make them and get certified.

Somewhere on the internet there is a guy that has done testing of various vtx and measured the radiated outputs and from what I have seen various manufacturers tune their amplifiers slightly different thus giving more power to crtain channels within the same band. Some of the testing I have seen with frequencies not legal to fly in the us have more output power then rated power on certain frequencies in their band. Never thought that was possible to have more power out then in but hey ...

Anyway..bottom line is this. To be legal to fly FPV you have to have a technician class HAM licence. That said many people fly without it and have zero problems with law enforcement or other operators. Just be aware that if you do fly without it and happen to use your gear where it interferes with other HAM use you could face serious legal issues and some hefty fines. So if you decide to fly without the HAM follow the rules of "Minimal power needed" to do what you are doing. In other words don't go getting an 800mw vtx and fly around town stepping on other signal transmission to draw attention to yourself and otherwise pissing off everyone around you.

 

[Wingman04]

So basically, if I want anything more that the performance of a tiny whoop, I need a HAM. I guess I now have an excuse to get a HAM.

 

[Fyathyrio]

Getting your HAM Technician ticket is easy, but the current batch of questions that all the study guides and current exams are based upon will expire at the end of June. The entire bank of over 400 test questions is released for people to study, but after several years they are replaced. There are tons of phone apps such as PalmVE that can help you prepare, and will likely update with the new test bank pretty fast.

 

[Wingman04]

What about all of these FPV and wing races. Do you mean that ALL of the racers (should) have HAMs?

 

[ElectriSean]

What about all of these FPV and wing races. Do you mean that ALL of the racers (should) have HAMs?

To be legal yes. But as Psyborg said, you can pretty much get away with it as long as you aren't disrupting people who are using the band legally.

 

[Wingman04]

So from all that I've been to take in so far:
I want to fly aerobatic and scale flight on fixed wing 35-65 in wingspan aircraft.
Best choice (from what I understand):
900 MHz or 1.2 GHz (with filter) with 100-200 mW Tx with Clover Leaf antenna and Skew-planar on Rx. However, this will require a HAM licence.

I have been wanting to get into Ham radio for a while, but I never knew that the RC hobby would have anything to do with it.

 

[makattack]

What about all of these FPV and wing races. Do you mean that ALL of the racers (should) have HAMs?

I can't address all groups, but many of the FPV flyers I've run across in my area are probably 50/50 split on being licensed or not. What I've noticed is that many people get their callsigns after the fact. My RC club has VE's who organize yearly license exams and I've seen those new to FPV take and pass their exams after flying FPV a little.

 

[ElectriSean]

So from all that I've been to take in so far:
I want to fly aerobatic and scale flight on fixed wing 35-65 in wingspan aircraft.
Best choice (from what I understand):
900 MHz or 1.2 GHz (with filter) with 100-200 mW Tx with Clover Leaf antenna and Skew-planar on Rx. However, this will require a HAM licence.

I have been wanting to get into Ham radio for a while, but I never knew that the RC hobby would have anything to do with it.

You can go pretty far with 5.8 stuff and not pay the premium and have to run gigantic antennae. And to go truly long range opens up another issue of legality depending on where you are. Definitely look into your local laws.

 

[Fyathyrio]

900MHz (TBS Crossfire) for control is a good choice. For video, maybe check out 3.3GHz. It is very clear, doesn't have the harmonics that can affect GPS, video, or control signals, and the antennas will be smaller than 1.2GHz needs. While others on 5.8GHz are battling for frequency room to fly in a group, I'm miles away with clear video using this setup.

 

[Wingman04]

900MHz (TBS Crossfire) for control is a good choice. For video, maybe check out 3.3GHz. It is very clear, doesn't have the harmonics that can affect GPS, video, or control signals, and the antennas will be smaller than 1.2GHz needs. While others on 5.8GHz are battling for frequency room to fly in a group, I'm miles away with clear video using this setup.

The only thing I have against higher frequencies is that they don't work as well as lower frequencies when you go behind trees or buildings. That's the only reason I'm not sure about 3.3. I do a fair amount of that and would have to have weak signals and dropouts.

 

[sprzout]

So, here's another thing to consider, if you read the fine print with the legalities of operating an unmanned drone:

The FCC requires that any private pilots flying unmanned drones (be it quad, flying wings, etc) must maintain line of sight with the vehicle. This means you need to have a spotter who can see that sucker. If that spotter can't see the vehicle 3/4 - 1 mi away, regardless of how powerful your VTX and antenna combo is, you're also flying illegally. I think this is where so many people get into trouble right now, especially when you look at the incident that happened in Dec./Jan. with the guy who was flying his Phantom 2.5 mi. away from him and crashed it into a Black Hawk helicopter out on maneuvers.

Does that mean that people fly via FPV without spotters? Yes. Should they? To be 100% legal on that, no, they shouldn't. But people do it.

If you want to be legal, get a HAM license. They're not that hard to obtain, and in some cases, don't cost a dime. The local club here in Carlsbad offered a free test if I registered online through their site for the test, which they hold once a month on Saturdays. The test is 60 questions, you can find samples online and study it. I looked at all the answers for the online sample tests, which are taken direct from the current tests, and pretty much memorized the answers, although most of them were based on basic electronics knowledge, so I knew quite a bit already. And it's good for 10 years before you have to re-up it...Honestly? Spend the time, get the license, and that way you don't have to worry about getting in trouble.

Plus, if MultiGP or other racing groups decide to make it mandatory that you have a HAM Radio license (right now it's voluntary, but that could change in the next year or two with the pressure our hobby is feeling), you could be prevented from racing without the license...