First of all, in the USA, you must fly VLOS unless you have an FAA waiver, which is a safety consideration that makes sense. Only clueless, careless, and criminal folks ignore this and other rules, and that is having dire effects on the rest of us.
Having said that, in general an antenna resonates at one frequency and it’s effectiveness diminishes sharply the farther you operate from that frequency. Most consumer drones operate on frequencies in the GHz range, which is why the antennas involved are so short and can fit inside the drone. Most ham equipment that would use a roof-mounted antenna for voice and digital communications operates in the MHz range, requiring a much longer antenna. You can operate with a shortened antenna but with reduced effectiveness and range. Hams generally operate with antennas that are 1/8, 1/4, 1/2, or full wavelength antennas with the smaller antennas being less effective, but sometimes a necessary compromise, such as for mobile installations for example.
Hams do have access to microwave radio bands (frequencies in the GHz range), but those frequencies are typically line-of-sight and hams use highly directional antennas such as parabolic dish antennas or antennas with many elements when working these bands to focus the energy. These antennas are typically stationary and pointed in the direction of the other station the ham is communicating with.
In any case, it would be highly unlikely that you have an existing ham radio antenna on your roof that is suitable for use at the frequencies that your drone uses. It may work to some degree, but not efficiently or reliably. If it works at all, its best features will be its height above the ground and less signal blockage from lower obstructions.
If the antenna doesn’t resonate at the frequency the transmitter is using, the transmitter can be damaged. It is unlikely that the manufacturer designed the drone’s transmitter to be robust enough to operate with anything other than a resonant antenna; i.e., the stock antenna.
I just Googled the 1480 Tram Antenna and it is a dual-band antenna for the VHF and UHF Ham Bands. It’s likely several collinear antennas stacked and phased to provide some gain over that of a single antenna. If it doesn’t need a ground plane, it probably uses dipole elements. In any case, it will not perform well at the frequencies that consumer drones use.
The Tram 1480 Amateur Dual-Band VHF-UHF Antenna is eight feet tall and made of durable fiberglass construction. The antenna helps... Learn More!
www.solidsignal.com
Get your Technician ham radio license and put the antenna to use. Plus, you’ll learn all sorts of stuff about antennas. Or, take it down and sell or give it to a ham (did I mention that I’m a ham). Otherwise, it makes a good lighting rod, which is a “benefit” that you probably don’t want.
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