Hey guys -

I started last year and was told for control link, Crossfire is the way to go because it's 915mhz and I'll get much better penetration with the lower frequency. I don't fly long range, but I go deep in bandos.

Now here we are with ELRS and all the good stuff for ELRS is only in 2.4ghz. Diversity rx, Radiomaster Ranger, Axis's Thor module, etc.

I'd like to get my stuff switched to ELRS but I don't understand why the focus is on 2.4ghz.

I've been waiting around for a year and nothing good is coming out for elrs 915mhz

I don't get it. Why is 2.4ghz the right choice all of a sudden?

2.4ghz on ELRS has been shown a bunch of times to go insanely far and still have great penetration. Unless you’re a true long range (like a record chaser type) user, 2.4ghz is way more than enough, plus comes with way lower latency and higher packet rates. Due to this, it seems most manufacturers (and users) don’t care to make much for the 900mhz stuff as most of us don’t need it

There is no "right choice" - its compromises.

CF uses 915Mhz LoRA. Think of ELRS as open source version of CF.

I made big thread about ELRS but basically.
1. 200Hz is plenty - we flew far lower for 8 years.
2. 915Mhz penetration advantage is mostly trees.
3. 915Mhz is narrow band, so few pilots and easily jammed. No RF techno magic can save you from failsafe.
4. 915Mhz has exceptional range BUT only if using full size antenna. All my quads use BetaFPV mini antenna.
5. Only R9 Slim+ provides diversity.
6. The radio TX Moxon antenna is directional.. turn around and its failsafe.

FYI Im all in and using BetaFPV 915Mhz because already had R9M on QX7 and 9" 2812 beast quad.

Few more points:
On 2.4Ghz quads you can just use spare antenna from XM+ or similar. But few dipole 915Mhz antenna.

Some 2.4Ghz ELRS rx has serious design flaw with oscillator. Non issue on 915Mhz.

All 915Mhz have Power Amplifier and filter.
Telemetry goes far. Only half the 2.4Ghz have that.

I dont want/need 100mw for 915Mhz but that is lowest power setting. It eats radio battery much faster than FrSky or FlySky.

2.4 GHz allows you to use much smaller antennas, run higher packet rates, and have a much wider band to use to avoid interference. As the others said, there aren't many scenarios where 900 MHz would be preferable.

(07-Dec-2022, 06:51 PM)romangpro Wrote: There is no "right choice" - its compromises.

CF uses 915Mhz LoRA. Think of ELRS as open source version of CF.

I made big thread about ELRS but basically.
1. 200Hz is plenty - we flew far lower for 8 years.
2. 915Mhz penetration advantage is mostly trees.
3. 915Mhz is narrow band, so few pilots and easily jammed. No RF techno magic can save you from failsafe.
4. 915Mhz has exceptional range BUT only if using full size antenna. All my quads use BetaFPV mini antenna.
5. Only R9 Slim+ provides diversity.
6. The radio TX Moxon antenna is directional.. turn around and its failsafe.

I heard that CF is used in 915, with a packat rate of 50hz in LoRa only, while in 150, FSK is used.?

(26-Jan-2024, 04:18 PM)Eyes.fpv Wrote: I heard that CF is used in 915, with a packat rate of 50hz in LoRa only, while in 150, FSK is used.?

Correct. Crossfire uses FSK modulation in 150Hz mode, and LoRa in 50Hz (and 4Hz) mode.

Note also that Crossfire's OTA scheme is very different than ELRS, so the LoRa modem parameters used for 50Hz mode in Crossfire provide much lower sensitivity than those used for 50Hz in ELRS.

(26-Jan-2024, 05:52 PM)V-22 Wrote: Correct. Crossfire uses FSK modulation in 150Hz mode, and LoRa in 50Hz (and 4Hz) mode.

Note also that Crossfire's OTA scheme is very different than ELRS, so the LoRa modem parameters used for 50Hz mode in Crossfire provide much lower sensitivity than those used for 50Hz in ELRS.

How can I read about OTA?


thank you mate

BetaFPV SuperD
915MHz

True diversity. Its a game changer for people like me who LIKE to go behind and through trees - even 1km+ away.

Im only running 100mW. Sometimes for LR I drop down to 100Hz.