Skip to main content
vadeltachi's profile
vadeltachi
20th Anniversary celebration
Rousing Reactor
Much Appreciation

Contributor

 • 

67 Messages

10/10/2026 1:05 PM

Poor (high) signal levels

What can I do about this on my home network?

Signal levels have been increasing over several weeks to the point now where all of the channels are our of spec.

Nothing has changed inside my home.  There are two splitters in the line. They have been there for over a year and have not been touched since installed. 

ANTRONIX®
2-WAY SPLITTER 5-1002MHz
CMC2002H-A
-3.5dB
OUT
-3.5dB
OUT

My owned modem = Netgear Nighthawk CM3000 
Firmware = V6.01.04
Cable Diagnostic
Status:   Poor
Action:  
[Downstream Power Level]
CM Status:
Downstream Status:
Upstream Status:
  Refresh Save Cable Diagnostic Info
 
Advanced Information
Frequency Start Value
This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.
Starting Frequency
 
Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 411000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enabled BPI+
IP Provisioning Mode Honor MDD IPv6 only
 
Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 4 411000000 Hz 13.1 dBmV 38.3 dB 741 0
2 Locked QAM256 1 393000000 Hz 12.8 dBmV 38.3 dB 418 0
3 Locked QAM256 2 399000000 Hz 13.0 dBmV 38.4 dB 517 0
4 Locked QAM256 3 405000000 Hz 13.0 dBmV 38.4 dB 621 0
5 Locked QAM256 5 417000000 Hz 13.3 dBmV 38.3 dB 872 0
6 Locked QAM256 6 423000000 Hz 13.0 dBmV 38.3 dB 1044 0
7 Locked QAM256 7 435000000 Hz 13.2 dBmV 38.2 dB 1301 0
8 Locked QAM256 8 441000000 Hz 13.0 dBmV 38.2 dB 1507 0
9 Locked QAM256 9 447000000 Hz 13.3 dBmV 38.3 dB 1805 0
10 Locked QAM256 10 453000000 Hz 13.4 dBmV 38.3 dB 1957 0
11 Locked QAM256 11 459000000 Hz 13.4 dBmV 38.4 dB 2003 0
12 Locked QAM256 12 465000000 Hz 13.6 dBmV 38.3 dB 2535 0
13 Locked QAM256 13 471000000 Hz 13.4 dBmV 38.1 dB 3202 0
14 Locked QAM256 14 477000000 Hz 13.6 dBmV 38.1 dB 3741 0
15 Locked QAM256 15 483000000 Hz 13.6 dBmV 38.0 dB 4453 0
16 Locked QAM256 16 489000000 Hz 13.1 dBmV 37.9 dB 5210 0
17 Locked QAM256 17 495000000 Hz 13.1 dBmV 37.8 dB 6745 0
18 Locked QAM256 18 507000000 Hz 12.6 dBmV 37.6 dB 10206 0
19 Locked QAM256 19 513000000 Hz 12.9 dBmV 37.6 dB 10658 0
20 Locked QAM256 20 519000000 Hz 12.9 dBmV 37.6 dB 11139 0
21 Locked QAM256 21 525000000 Hz 12.9 dBmV 37.5 dB 12232 0
22 Locked QAM256 22 531000000 Hz 13.2 dBmV 37.3 dB 14025 0
23 Locked QAM256 23 537000000 Hz 12.9 dBmV 37.4 dB 16868 0
24 Locked QAM256 24 543000000 Hz 12.8 dBmV 37.1 dB 18769 0
25 Locked QAM256 25 549000000 Hz 12.4 dBmV 37.0 dB 22756 0
26 Locked QAM256 26 555000000 Hz 12.1 dBmV 36.9 dB 29146 0
27 Locked QAM256 27 561000000 Hz 12.1 dBmV 36.9 dB 36428 0
28 Locked QAM256 28 567000000 Hz 12.0 dBmV 36.6 dB 43109 0
29 Locked QAM256 29 573000000 Hz 12.1 dBmV 36.5 dB 51601 0
30 Locked QAM256 30 579000000 Hz 12.2 dBmV 36.5 dB 60578 0
31 Locked QAM256 31 585000000 Hz 11.9 dBmV 36.5 dB 70438 0
32 Locked QAM256 32 591000000 Hz 12.0 dBmV 36.5 dB 76208 0
 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 5 2560 Ksym/sec 40400000 Hz 38.8 dBmV
2 Locked ATDMA 2 5120 Ksym/sec 22800000 Hz 35.8 dBmV
3 Locked ATDMA 3 5120 Ksym/sec 29200000 Hz 35.8 dBmV
4 Locked ATDMA 4 5120 Ksym/sec 35600000 Hz 36.5 dBmV
5 Locked ATDMA 1 5120 Ksym/sec 16400000 Hz 35.8 dBmV
6 Not Locked Unknown 0 0 0 0.0 dBmV
7 Not Locked Unknown 0 0 0 0.0 dBmV
8 Not Locked Unknown 0 0 0 0.0 dBmV
 
Downstream OFDM Channels
Channel Lock Status Profile ID Channel ID Frequency Power SNR / MER Active Subcarrier
Number Range		 Unerrored
Codewords		 Correctable
Codewords		 Uncorrectable
Codewords
1 Locked 0 ,1 ,2 ,3 193 672000000 Hz 10.48 dBmV 34.3 dB 1108 ~ 2987 1690853036 1593696019 108
2 Not Locked 0 0 0 Hz 0 dBmV 0 dB 0 ~ 4095 0 0 0
 
Upstream OFDMA Channels
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
1 Not Locked 0 0 0 Hz 0 dBmV
2 Not Locked 0 0 0 Hz 0 dBmV
 
Extended Upstream Transmit Power
 
Current System Time:Sat Oct 10 07:58:24 2026

System Up Time:1 day 01:38:11

Question

 • 

Updated 

60 minutes ago

11

1

0

Oldest First
Selected Oldest First
EG

Expert

 • 

122K Messages

3 hours ago

First. Are you actually experiencing any connection/droput problems ?

1

0

vadeltachi

Contributor

 • 

67 Messages

Bandwidth is about 2/3 of what I pay for (1.2 gigs).

There are daily T3 errors in the log:

Event Log Clear Log Refresh Export Time Priority Description
Sat Oct 10 03:10:24 2026 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
Fri Oct 09 06:21:02 2026 (Notice (6)) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
Fri Oct 09 06:20:57 2026 (Notice (6)) TLV-11 - unrecognized OID;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
Time Not Established (Notice (6)) Honoring MDD; IP provisioning mode = IPv6
Time Not Established (Critical (3)) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
Thu Oct 08 21:35:34 2026 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
Time Not Established (Critical (3)) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
Fri Sep 18 21:36:26 2026 (Critical (3)) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
Time Not Established (Critical (3)) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;
Help CenterShow/Hide Help Center


Like

Reply

60 minutes ago

0

forum icon

New to the Community?

Start Here