The lower the frequency the greater the range and ability to penetrate objects. Notice that your wifi which is 5.8 doesnt go very far, while a mobile around 900mhz which probably transmits at a similar mw has a lot more range.
Lower ranges also require larger antennas because the waves are bigger. As with all things theres a tradeoff.
So what kind of range would I expect from this unit? It seems to be only a little dinky thing. Antenna is only 100mm. Don't know if that big or small for this type of thing. I know my antenna in my phone isn't visible any longer. So line of sight range? Again I don't know if 50m is good, or 500m is average?
Well technically both, however without any sort of license at 433mhz the telemetry modules must be set back to 25mW whereas 915mhz can be be used legally at the full power (100mW).
I use 915mhz and never had any issues, investing in some higher gain antennas will help you get some decent ranges with that.
Matthew Kerle > Adam WarburtonMay 19, 2014 at 10:57pm
Really? I was under the impression that the telcos owned the frequency around 900mhz for 3g etc? I could be wrong...
915mhz is ok to use up to 1W so long as the transmitters are frequency hopping with a minimum of 50 channels (which the 3DR radios are). It's a different story with single channel transmitters like FPV video transmitters, I can't remember exactly but you either cannot use it at all or only at very low powers.
433mhz has no provision for frequency hopping so it's 25mW no matter how you broadcast without a license.
Matthew Kerle > Adam WarburtonMay 19, 2014 at 11:13pm
You're right, I do recall reading that somewhere. Thanks!
Depends, do you have an amateur radio licence? If not then technically neither. If you do then I think you can use 433mhz, but you might need the intermediate or advanced licence. Someone more knowledgeable than I could probably say for sure...
Replies
The lower the frequency the greater the range and ability to penetrate objects. Notice that your wifi which is 5.8 doesnt go very far, while a mobile around 900mhz which probably transmits at a similar mw has a lot more range.
Lower ranges also require larger antennas because the waves are bigger. As with all things theres a tradeoff.
So what kind of range would I expect from this unit? It seems to be only a little dinky thing. Antenna is only 100mm. Don't know if that big or small for this type of thing. I know my antenna in my phone isn't visible any longer. So line of sight range? Again I don't know if 50m is good, or 500m is average?
I use 915mhz and never had any issues, investing in some higher gain antennas will help you get some decent ranges with that.
433mhz has no provision for frequency hopping so it's 25mW no matter how you broadcast without a license.