The Ydoc data logger has a build-in GSM antenna. In “normal”, open environments, with strong signal, this combination will operate perfect.
Using an external antenna is only required when:
- The data logger is placed inside a metal cabinet or on a metal plate. (Cage of Faraday).
- The data logger is placed inside a structure /building enclosed with metal /thick concrete walls or a room without gaps /windows.
- At the fringe of coverage.
Note: A shed, covered with corrugated sheets, does act like a “metal plate”. Use of an external antenna is advised when the data logger is mounted on the wall of such a shed.
A common, safe setup for an external antenna:
- Use a 50 ohm, 700 – 900 Mhz cellular antenna, matching the Telit modem’s supported LTE bands.
- Mount the antenna outside the building or above the (metal) enclosure.
- Use 50 ohm coax cable.
- Keep coax runs short to reduce signal loss.
- An externally mounted antenna with a mast /pole bracket is preferred.
- Keep coax runs short to reduce loss.
- Small whip antennas with SMA connectors may be fine for testing, but not ideal for long-term outdoor deployment /permanent installations. An externally mounted antenna with a mast/ pole bracket is preferred.
T: Any external antenna, branded as LTE antenna is usable. To be sure, check the antenna specs are optimized for the frequency bands used in the area of deployment. In rural areas its mostly B28, B20 and B8. (700 /800 /900 Mhz).
The better the antenna, it will have a high gain (dBi > 0) and a low VSWR (Where: 1.0 = ideal, 1.5 = excellent, 2.0 = good, 3.0 = problematic).
LoRa
Installing an ML-OO-LORA board and matching antenna transforms your YDOC data logger into a versatile LoRaWAN end device.
LoRa (Long Range) operates on license-free, sub-gigahertz radio frequency bands.
Available bands vary by region:
- Europe (EU863-870): 863–870 MHz and 433 MHz.
- North America (US902-928): 902–928 MHz.
- Asia (AS923): 915–928 MHz (Japan/Asia) and 470-510 MHz (China).
- India (IN865): 865-867 MHz.
- Other: 2.4 GHz (Worldwide, high data rate but short range).
T: The ML-OO-LORA board can be ordered in two editions: the ML-OO-LORA-8, optimized for European and Indian frequency bands, and the ML-OO-LORA-9, optimized for Asia, Australian and US frequency bands.