Quote:
Originally Posted by Traduk
My up link is 33db the downlink is 34db with an SNR of 7.5 (which is highish as optimum is +\- 2.5).
|
Those figures needs clarifying, as I think you have two of them the wrong way round.
Your "uplink" figure of 33 is the cable modem's transmit signal level, and therefore the unit is dBmV, not db. So your upstream signal level is 33dBmV, which is fine. Lower is better, higher is worse, for this one.
Your "downlink" figure of "34" is in fact your downstream Signal-to-Noise Ratio (SNR), and the unit is dB. Your downstream SNR is 34dB, which is OK. Higher is better, lower is worse, for this one. Going below 30dB would lead to unreliability.
Your downstream received signal level is 7.5dBmV. This is not the SNR. The optimum level is as close to 0dBmV as possible, though anything in the range -15 to +15dBmV should work.
Quote:
|
In my experience the more serious service problem are apparent if the CM drifts down to big minus numbers and I found that on the old co-ax I hovered around -35 and drifted down to -60 at various times of the day (mostly at night).
|
I don't know of any signal or SNR readings that can be expressed as negative numbers that extreme. Maybe you are thinking of upstream transmit levels rising to as high as +60bBmV, which would be bad.