Let’s clarify this
@Phaedrus have you worked for a, let’s just say, a construction company. I have and to date one of them is building the 2020 NFL stadium in Las Vegas, and prior to flying our missions, our drones was physically inspected, by FAA officials at McCarran International Airport. Las Vegas is restrict. If the antenna that I used deemed illegal under section 15, I had another waver that has been granted for the inspection of new Facebook build. (Snippets video soon)
Now with "Section 15.203 - Antenna Requirement
Changing the antenna on a transmitter can significantly increase, or decrease, the
strength of the signal that is ultimately transmitted. Except for cable locating
equipment, the standards in Part 15 are not based solely on output power but also take
into account the antenna characteristics. Thus, a low power transmitter that complies
with the technical standards in Part 15 with a particular antenna attached can exceed
the Part 15 standards if a different antenna is attached. Should this happen it could
pose a serious interference problem to authorized radio communications such as
emergency, broadcast and air-traffic control communications.
In order to prevent such interference problems, each Part 15 transmitter must be
designed to ensure that no type of antenna can be used with it other than the one used
to demonstrate compliance with the technical standards. This means that Part 15
transmitters must have permanently attached antennas, or detachable antennas with
unique connectors. A "unique connector" is one that is not of a standard type found in
electronic supply stores.
It is recognized that suppliers of Part 15 transmitters often want their customers to be
able to replace an antenna if it should break. With this in mind, Part 15 allows
transmitters to be designed so that the user can replace a broken antenna. When this
is done, the replacement antenna must be electrically identical to the antenna that was
used to obtain FCC authorization for the transmitter. The replacement antenna also
must include the unique connector described above to ensure it is used with the proper
transmitter."
So while there are no specific penalties for changing the antenna you can see that it may result in the equipment no longer being in compliance.
Thus it is illegal for where it is being used.
It is not out of the question that at sometime in the future folks who find themselves in trouble with the FAA may also come under scrutiny of the FCC..
We all use all sorts of antennas, on tripods, on roofs, amplified, 2.4ghz, 5.8ghz, 1.3ghz. At events in public, for shows etc etc etc. No one cares or checks or even knows to check. If you are that worried about it, just polish the quad up and set it on a shelf to look pretty.
Amazon floods the sale of boosted antennas, the FCC should be made aware of this, so the feds with their cool jackets can crack these folks down.
Now, question? Hobby King got fined by the FCC, how come the FCC has not been successful in cracking down let’s just say 4Hawks?
The regulation states that the replacement antenna must be the same type e.g. dipole for dipole, yagi for yagi, must exhibit the same in-band and out of band ERP and must be permanently connected or utilize a proprietary connector. If the FCC was actively pursuing "pirates", they would be monitoring buyers of household range extending antennas that attach to wifi routers, with standard connectors for external antennas.
A lot of questions... But no clear answer, due to textbook experts.