Armenia Frequency Standards (EU_868)

The Armenian Meshtastic community has officially standardized on the EU_868 (868 MHz) frequency band.

📊 Technical Parameters for Armenia

Parameter	Value in Armenia	Notes
LoRa Frequency Region	`EU_868`	868.0 MHz – 868.6 MHz (SRD/ISM Band)
Default Center Frequency	`869.525 MHz`	Slot 0 (`MediumFast` default)
Modem Preset	`MediumFast`	Standardized across Armenia for low airtime and fast throughput
Bandwidth (BW)	`250 kHz`	Wide bandwidth for fast packet transmission
Spreading Factor (SF)	`9`	Fast transfer rate (~5.4x faster than LongFast)
Coding Rate (CR)	`4/5`	Forward error correction
Max Tx Power	`27 dBm (500 mW)`	Standard transmitter power
Default Hop Limit	`3`	Prevents packet looping and network congestion

Newcomers often ask whether 433 MHz (RU_433 or EU_433) is viable in Armenia:

Antenna Dimensions & Portability
- At 433 MHz (wavelength ~70 cm), a quarter-wave antenna must be roughly 17 cm long, and high-gain antennas are bulky.
- At 868 MHz (wavelength ~34.5 cm), antennas are half the size (~8.6 cm), making pocket nodes, backpacks, and compact vehicle installations far more practical.
RF Noise & Interference
- The 433 MHz spectrum in Armenian cities is heavily congested with legacy car key fobs, automated gate remotes, consumer weather stations, and cheap LPD433 walkie-talkies.
- The 868 MHz band has significantly lower noise floors and cleaner spectrum in Armenia.
Regional & Cross-Border Interoperability
- Georgia, European travelers, and neighboring regional groups also utilize EU_868. Using 868 MHz ensures seamless interoperability when traveling or during cross-border hiking expeditions.

When purchasing hardware on AliExpress, Amazon, or maker shops:

Always choose the 868 MHz or 915 MHz hardware variant (most SX1262 chips cover the broad 850–930 MHz range).
❌ DO NOT purchase the 433 MHz variant, as its RF filtering circuitry is physically incompatible with the Armenian 868 MHz network.