Oddbean new post about login | logout I feel like I kind of fucked up ordering devices in the 433 band while in the US.
Not if you have your ham radio license... Then you can use 433!
Aahh. So its in use in the US? I'm still wrapping my head around available frequencies for use.
Yeah the 915 is in an unlicensed spectrum in us, and 433 has an allocation for unlicensed use in Europe I believe(other countries as well). However, there are many allocations of spectrum in the US where you can transmit data using your amateur radio license. (Which includes the 433 in US. You do need to identify your callsign with the transmissions unfortunately which is the ultimate dox for yourself. (One could also...break the rules)* *Not suggesting this, just saying. FYI I have used metastatic devices in the US of the 433 spectrum (with a license). Literally if you study for ten minutes a day on one of the ham radio apps cc: nostr:nprofile1qqszw48usckkhs9hcwt3q3np9k2z2c73s8qc0gu3uxqw66cqlq88ukcpz4mhxue69uhk2er9dchxummnw3ezumrpdejqzynhwden5te0wfjkccte9enrw73wd9hszgmhwden5te0wfjkccte9eek7an9wfjkjemwv4hxw6twv4jhy6twvuhxjmczv5ddh for a few weeks you could take the technician exam, and, they even let you take your license exam remotely in some cases. I'm telling you just get your technician license and it will be wonderful. You are what ham radio needs! No joke, I'll literally buy you a trashy Baofeng if you do it. I'll send you a cashu token worth the cost of one. Hold me to it I dare you.
433 is part of the amateur radio band which requires a ham radio license to transmit legally there above a certain power level. 433 is also regulated under Part 15 rules which is unlicensed. There will be some sort of ERP limit here that will include transmit power plus antenna gain. There may possibly be an antenna height above ground limit too. Assume low transmit power, below 20 dBm (maybe well below 20 dBm), and some relatively low gain antenna, too. Without looking it up, I don’t know for sure what the exact rules are. I’m a ham so I can run 1500 Watts there if I want. I’m not sure if I have an ERP limit there or not, though. I guess it more comes down to if I can satisfy the FCC RF field strength rules or not for how close the antenna can be to people, signage, fences, etc to keep from frying people and pets unnecessarily. :-) In short, 433 is legal here in the US for unlicensed use, but there are power limits. The Part 15 devices should already abide by the rules. If you modify things then it voids the Part 15 authority in which case you’re not legal to transmit with it.
Luckily, these loRa boards are relatively cheap.
I think you can reflash the board pretty easy. It's the antenna that matters what band it's in
You can make your own antenna and cut a single wire to length with an easy calculation Wavelength = speed of light / frequency (λ = c/f) Do a quarter-wave length vertical wire, like 22 gauge or something. At 915MHz should be around: 3.2248248772420216 inches. Not sure whether you can flash the firmware or if the modem is an sdr or different unit for each spectrum.
I did not know that about the antennas! But yeah these esp lora boards and the lilygos and all that, as long as you know the type of board you can delete/reflash the board to any specifications through the meshtastic website
Yeah I know its crazy but literally merely having an interest in electronics and computers means you are already on the road to your ham license. You learn all kinds of awesome things (that silly calculation above as an example- yet mind blowing), for a lay person like myself (not an RF Engineer/embedded), I learned the building blocks of our wireless world Lay flat spiral bound ARRL technical manual. Buy one today! At worst a good reference manual to learn what the rules are before you break them and are hunted down by elderly volunteer ham radio spectrum monitors with directional antennas. FCC doesn't hunt for people anymore mostly. You can make cool PCB antennas for Wi-Fi and all kinds of crazy shit. Go get em! In summation, I'm a far more effective Internet troll then I would have been were I not a ham.