SBG6580 (v8.5.x): Cable Signal Levels

To Verify Signal Levels

1. Launch a web browser, such as Internet Explorer, Firefox, or Safari. Enter http://192.168.0.1 into the address box, and press the Enter key.  The Login page will appear.
    
2. On the Login page, enter admin in the Username field.
    
3. Enter motorola in the Password field.
    
4. Click the Login button. The Home page will appear.
   
   NOTE: On firmware version 8.9.0.4 and later, the default admin password is required to be changed.  The Change User Password prompt will immediately appear after logging into the Web manager with the default admin password.  For assistance with the Change User Password screen, please refer to article # 18055 - SBG6580 (v.8.9.x): Prompt to Change Default Admin Login.
    
   
    
5. Move the mouse-cursor over Status on the main menu, and click the Connection link from the sub-menu.  The Status - Connection page will appear.
    
6.  In the Downstream Bonded Channels section, verify Power levels are within the acceptable range of - 15 dBmV to + 15 dBmV for each downstream channel. 

 

7. In the Downstream Bonded Channels section, identify the Modulation and Power to find verify SNR levels are within the acceptable range for each downstream channel. 
   
   Acceptable SNR Levels (dB): 
   If QAM64, SNR should be 23.5 dB or greater. 
   If QAM256 and DPL( -6 dBmV to +15 dBmV) SNR should be 30 dB or greater. 
   If QAM256 and DPL(-15 dBmV to -6 dBmV) SNR should be 33 dB or greater.  
   
   
    
8. In the Upstream Bonded Channels section, identify the number of Channels, Type, Symbolic Rate to find verify Upstream Power levels are within the acceptable range for each upstream channel. 
   
   Acceptable Upstream Power Levels (dBmV):
   
   
    

   Upstream Transmit Power Level
   Channel	US Channel Type	Symbol Rate	Acceptable Upstream Power Levels
   Single	TDMA	1280 Ksym/sec	45 dBmV to 61 dBmV
   	ATDMA	2560 Ksym/sec	45 dBmV to 58 dBmV
   		5120 Ksym/sec	45 dBmV to 57 dBmV
   Two	TDMA	1280 Ksym/sec	45 dBmV to 58 dBmV
   	ATDMA	2560 Ksym/sec	45 dBmV to 55 dBmV
   		5120 Ksym/sec	45 dBmV to 54 dBmV
   Three or more	TDMA	1280 Ksym/sec	45 dBmV to 55 dBmV
   	ATDMA	2560 Ksym/sec	45 dBmV to 52 dBmV
   		5120 Ksym/sec	45 dBmV to 51 dBmV

9. Refresh the page at least twice to identify variations in SNR, Downstream Power, and Upstream Power.   
   
   NOTE: If the either of the signal levels are outside of the acceptable range, power cycle or factory reset the modem. 
    
10. Contact the cable provider to adjust the signal level to the acceptable level range.