Overview
The X12 device is equipped with 4 SMA antenna ports that connect directly to the internal modem. Proper antenna configuration is critical for optimal performance, as incorrect connections can significantly impact both download and upload speeds.
Understanding the Antenna Ports
When facing the back of the X12 device, the SMA ports are numbered 1-4 from left to right. Each port serves a specific function:
Port Functions
- Port 1: Secondary download antenna (carrier aggregation)
- Port 2: Primary upload antenna (dedicated upload handling)
- Port 3: Secondary download antenna (carrier aggregation)
- Port 4: Primary download antenna (main data reception)
How the Ports Work Together
- Ports 1, 3, and 4 handle download traffic, with Port 4 serving as the primary download antenna
- Ports 1 and 3 support carrier aggregation, which allows the device to combine multiple cellular bands for increased download speeds
- Port 2 is dedicated exclusively to upload traffic and is essential for maintaining optimal upload performance
External Antenna Configuration
When installing an external antenna system, always follow the priority order below to ensure maximum performance.
Configuration Priority
- Primary antenna connection → Port 4 (Primary Download)
- Secondary antenna connection → Port 2 (Upload)
- Additional antenna connections → Port 1 and Port 3 (Carrier Aggregation)
Step-by-Step Configuration
Single Cable Antenna (1 cable)
If your external antenna system has only one cable:
- Connect the single cable to Port 4
- This configuration provides basic improved signal reception for downloads
Dual Cable Antenna (2 cables)
If your external antenna system has two cables:
- Primary cable → Port 4 (Primary Download)
- Secondary cable → Port 2 (Upload)
Note: If your antenna cables are not labeled as primary/secondary, connect them to Ports 4 and 2 respectively. This ensures both download and upload performance are optimized.
Triple Cable Antenna (3 cables)
If your external antenna system has three cables:
- Primary cable → Port 4 (Primary Download)
- Secondary cable → Port 2 (Upload)
- Third cable → Port 1 (Carrier Aggregation)
Quad Cable Antenna (4 cables)
If your external antenna system has four cables:
- Primary cable → Port 4 (Primary Download)
- Secondary cable → Port 2 (Upload)
- Third cable → Port 1 (Carrier Aggregation)
- Fourth cable → Port 3 (Carrier Aggregation)
Important Installation Notes
Cable Identification
- Some antenna manufacturers label cables as Primary, Secondary, Aux1, Aux2, etc.
- Others may label them as Main, Diversity, MIMO1, MIMO2, etc.
- If cables are not clearly labeled, follow the port priority order: Port 4 → Port 2 → Port 1 → Port 3
Connection Tips
- Ensure all SMA connections are hand-tight plus 1/4 turn with a wrench
- Do not over-tighten connections as this can damage the connectors
- Verify all connections are secure before powering on the device
Performance Impact
- Incorrect antenna configuration can result in poor upload speeds, reduced download performance, or inability to achieve carrier aggregation
- Always connect antennas in the specified order for optimal results
- Using fewer antenna connections than available will limit the device's performance potential
Troubleshooting
If you experience poor performance after antenna installation:
- Verify connections are made to the correct ports per this guide
- Check cable integrity for any damage or loose connections
- Confirm antenna placement provides clear line-of-sight to the tower