Hello im kind of new to this was wondering what is the maximum distances RF 433MHz Transmitter/Receiver Module can have ? and is there a way to boost it i need to make an alarm sistem for my school and was thinking of having multiple arduino with multiple receivers it's a big school so the distances the transmitter can give is a problem also one of the requirements is to have the speakers to be wireless so theres that . is the way i'm thinking feasible or might there be a better way ?
I am working on a Remote Property Perimeter Monitor; a long range visitor annunciator, doorbell, incursion detector and datalogger. I have 12 acres to experiment with long range break beam sensors & RF.
I have the central unit up & running, literally waiting on a slow boat from China for the outdoor portion of the project
I have a working PA system and a pile of LePai 2020 amps for the doorbell. my current project is routing the audio output through different combinations of PA, FM, and local audio under different circumstances.
Wireless speaker: I am planning on using an FCC legal Part 15 C. Crane FM transmitter. this seems to be the legal transmitter with the longest range:
[C. Crane FM transmitter](http://-wireless speaker: I am planning on using a C. Crane FM transmitter. this seems to be the FCC Part 15 legal transmitter with the longest range: https://www.ccrane.com/item/acc_trans_trans2/100106/digital_fm_transmitter_2_for_sending_near_broadcast_quality)
these clowns have to use an attack ad to promote their product. I may buy one if the C. Crane does not reach the far end of the driveway, but on general principles, forget these people:
with these transmitters anybody in range can dial in the system from anywhere with any broadcast FM receiver, no wiring, no special equipment.
Sensors & RF: at this time I am planning on using HC-12 transceivers, which should receive signals from the farthest point from the house, 820 feet ( 250 meters ). if that does not work, or if I set up a system on a larger property, I will move to LoRa
I have an RF433. I might try it on the Inner Marker ( house end of the driveway, 50 feet ) but no way I try on the farther corners
Antennas: the 433 mhz band is shared with other services. Government has priority 1, licensed amateurs are priority 2, and the general public is priority 3 via Part 15. a Part 15 device is certified with a particular antenna. it is best to use the antenna which comes with a part 15 device, but Arduino RF modules do not usually come with antennas, and certainly not good ones. Antennas work both ways in more than one sense:
- antennas which transmit better in one direction also receive better in that direction, and
- if an antenna has 9 db of gain it improves both ends of the link 7 db over standard issue 2.14 dbi gain dipoles
best practice under Part 15 is to improve the receiving antennas. improving the transmit antenna is legally iffy. because the 433 mhz band is also an amateur radio allocation, there are thousands of gain antenna designs on the web. search for 70 cm antenna, 432 mhz, or VHF antenna. look for collinear antennas with up to 15 db of omnidirectional gain, or yagis for simple construction of directional antennas. if anyone claims more than 15 db gain from a collinear, smile and walk away.
thank you so much im gonna look in to it
blaze92:
Hello im kind of new to this was wondering what is the maximum distances RF 433MHz Transmitter/Receiver Module can have ?
Depending on the actual module and the environment you try to transmit through anything from <10 meters to >100 km (or whatever the current record for LoRa, which is one of several modules that can use the 433 MHz band).