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Ignitionnet · 25-04-2010, 10:37

By the time a cable is degraded enough for impedance mismatch to cause noticeable issues with regards to power levels reflected signals are going to cause serious issues with signal quality. SNR would be seriously degraded way before power were taken out of spec.

My comment regarding impedance calculation is perfectly accurate, it's assumed to be 75ohm in the calculation due to it being such a non-issue.

As far as I know impedance isn't even measured when installs take place and it's certainly not a reason for repulling with a higher grade coax, that is simply to reduce attenuation across the drop by using a cable with a thicker core.

25-04-2010, 10:37	#33
Ignitionnet cf.mega poster Join Date: Jun 2008 Location: On the move Age: 34 Posts: 9,757	Re: Problem with cable modem By the time a cable is degraded enough for impedance mismatch to cause noticeable issues with regards to power levels reflected signals are going to cause serious issues with signal quality. SNR would be seriously degraded way before power were taken out of spec. My comment regarding impedance calculation is perfectly accurate, it's assumed to be 75ohm in the calculation due to it being such a non-issue. As far as I know impedance isn't even measured when installs take place and it's certainly not a reason for repulling with a higher grade coax, that is simply to reduce attenuation across the drop by using a cable with a thicker core. Last edited by Ignitionnet; 25-04-2010 at 10:56.