Cable Levels (Adjust Internet Quality)
For a good connection:
The Upstream (Tx) should be between 35- 51
The Downstream (RX) should be between -11 and 11
Downstream (Rx) Receive Power Level:
This is the amount of signal received by the modem from the transmitter in the cable company head-end.
For all modems:
-15 dBmV to +15 dBmV maximum.
-12 dBmV to +12 dBmV recommended.
0 dBmV is the "optimal" level.
Upstream (Tx) Transmit Power (a.k.a. Return Signal) level:
This is the amount of signal transmitted by the modem to reach the receiver in the cable company head-end.
+8 dBmV to +58 dBmV maximum for QPSK. (DOCSIS 1.x)
+8 dBmV to +55 dBmV maximum for 8 QAM and 16 QAM. (DOCSIS 1.x)
+8 dBmV to +54 dBmV maximum for 32 QAM and 64 QAM. (A-TDMA DOCSIS 2.0)
+8 dBmV to +53 dBmV maximum for S-CDMA DOCSIS 2.0 modulation rates.
Recommended upstream signal levels are +35 dBmV to +52 dBmV.
Most cable modems have a built-in status page that will show you the current signal levels.
Simply login to the modem same way your would do to change your Wi-Fi Setting and fine the status page.
You can buy Amplifiers and Reduces and put them on the cable line to adjust the levels.
Anytime you add a splitter you drop the signal on the line see diagram bellow, most splitters have the loss labeled see chart for standard loss.
| Item | Loss (dB) |
|---|---|
| 2-way Splitter | -3.5dB |
| 4-way Splitter | -7dB |
| 8-way splitter | -11dB |
| 100' RG6/U QS Cable | -5dB |
| 100' RG59 Cable | -7dB |