Most mobile phone towers are not that high (~ 20m) and often where i live they are partially blocked by other buildings depending on the trajectory. There are many times when you dont have a LOS path to the tower and yet it just works fine something that is not true of say radios or tx.
keep in mind your phone has quite a few standards to choose from with different frequencies and data rates,eg these are for the LG Nexus outside USA:
GSM: 850/900/1800/1900 MHz
WCDMA: Bands: 1/2/4/5/6/8
LTE: Bands: 1/3/5/7/8/20
at 850MHz your little transmitter can still go a long way through all kinds of materials. If you compared the 3DR 433Mhz telemetry radio with a high gain antenna to your phone, I reckon you'd find it has much better range.
My Iris arrived and I ordered the 915 thinking that was what I should be using but 3DR sent the 433. What is the advantages of one over the other? Would like to know whether I should get 3DR to send the 915 or keep the 433?
What is involved in getting an amateur radio licence?
Where do I get one from?
How do I know the wattage the radio is outputting?
Actually right now they are just two whip antennas of varying sizes. I do have a large patch antenna I'll be using with an antenna tracker system. Just haven't range tested it yet.
Matthew Kerle > Adam WarburtonMay 20, 2014 at 12:50am
Cool. I haven't looked a lot into antennas at 433 and 915 as I won't be able to use them for a while. Everything is so big at those low frequencies!
I use a larger 3dbi antenna on the drone and a 5dbi antenna on the groundstation and in clear line of sight I have made it 1km with almost 100% signal strength.
The stock antennas actually do surprisingly well probably 500m at least with no obstructions and interference.
Matthew Kerle > Adam WarburtonMay 19, 2014 at 11:58pm
which antennas are you using, a large whip on the UAV and a patch on the ground?
I would recommend the 915mhz. In theory 433mhz would be slightly better on range but as you can only use 1/4 of the power it's probably not as good in this case.
By default the radios are outputting their max (100mW) but it can be set in Mission Planner.
I'm not too sure about the radio licenses, I've been looking online and it seems like you have to do a course. There are usually local hobby groups by the sounds of it.
Matthew Kerle > Adam WarburtonMay 19, 2014 at 11:50pm
yeah, I've been looking into it, there's a book you purchase and study, then your local hobby group invigilates the exam and you get your amateur licence and your very own callsign! then you can go on and do intermediate and advanced, Advanced can pretty much broadcast whatever kind of signal that want up to some quite high power on any amateur band (which 915mhz is not), from my reading of the code.
I'm interested in doing it because I'm interested in learning the 'official' RF stuff, which could have applications in helping my UAV go further safer.
Replies
Most mobile phone towers are not that high (~ 20m) and often where i live they are partially blocked by other buildings depending on the trajectory. There are many times when you dont have a LOS path to the tower and yet it just works fine something that is not true of say radios or tx.
keep in mind your phone has quite a few standards to choose from with different frequencies and data rates,eg these are for the LG Nexus outside USA:
at 850MHz your little transmitter can still go a long way through all kinds of materials. If you compared the 3DR 433Mhz telemetry radio with a high gain antenna to your phone, I reckon you'd find it has much better range.
My Iris arrived and I ordered the 915 thinking that was what I should be using but 3DR sent the 433. What is the advantages of one over the other? Would like to know whether I should get 3DR to send the 915 or keep the 433?
What is involved in getting an amateur radio licence?
Where do I get one from?
How do I know the wattage the radio is outputting?
The stock antennas actually do surprisingly well probably 500m at least with no obstructions and interference.
which antennas are you using, a large whip on the UAV and a patch on the ground?
By default the radios are outputting their max (100mW) but it can be set in Mission Planner.
I'm not too sure about the radio licenses, I've been looking online and it seems like you have to do a course. There are usually local hobby groups by the sounds of it.
yeah, I've been looking into it, there's a book you purchase and study, then your local hobby group invigilates the exam and you get your amateur licence and your very own callsign! then you can go on and do intermediate and advanced, Advanced can pretty much broadcast whatever kind of signal that want up to some quite high power on any amateur band (which 915mhz is not), from my reading of the code.
I'm interested in doing it because I'm interested in learning the 'official' RF stuff, which could have applications in helping my UAV go further safer.
If i recall you can set it in the config tool.