Using 915mhz with 868mhz settings

Started by Sergegsx, June 18, 2018, 02:10:11 PM

Sergegsx

Quote from: LukaQ on June 18, 2018, 12:08:20 AM
Just asking, because ISM band in EU is 868MHz or 433MHz, you want to use 915MHz, which is probably taken by some mobile phone operator in your region. It's ok, if your far away (>200m) from anyone or anything that operates in 915MHz region.

well that may explain why my range are not so impressive.

Ive found this (sorry its in spanish)
https://wiki.bandaancha.st/Frecuencias_telefon%C3%ADa_m%C3%B3vil
which is quite confusing as it seems 868 is almost used by mobiles.

should I try replacing my radios from 915 to 868?

thank you for your help

Felix

If you have 915mhz modules just set the frequency at 868mhz in software and they will work without noticeable signal degradation.

Sergegsx

interestring!

but will I get any notizable improvement at all? i mean, is it worth it for any reason?

Felix


LukaQ

really?
Don't 915MHz modules have different components, which prevent module to work great on 868MHz? I also have few 915 left, but never tried this

TomWS

I'm pretty sure anarduino sells them as 868/915 MHZ units, implying the same components for the upper frequency range.

Tom

Felix

Pretty much everyone sells them as 868/915. You can source them as 868 specifically but even Hope said 915s can be used at 868 settings, in my own tests I have not noticed a difference in RSSI.

Sergegsx

thank you!

I guess that if in my area they are using 915Mhz by switching to 868 I might see an improvement either in collision or RSSI.
I will try changing the frequency as suggested by Felix.

thank you very much.

LukaQ

I soldered one of the '915' marked modules to see if it will work. It does. I have to test with at the same range as my '868' marked one to be sure, but I think it will be the same