Keith Dysart wrote:
On Mar 24, 8:45 am, Cecil Moore wrote:
I made the rough computation of -25 dB before I responded.
It is below the ability of the human eye to detect TV
ghosting.

Would you care to reveal the details of the calculations
so that we can locate the error(s) that lead to a non-zero
answer?

As I said, it was a rough computation based on your 450
ohm series padding resistor and a lot of simplified
assumptions about the configuration of the system.

In order to avoid ambiguity, would you please give us
better specifications for the source? Ramo and Whinnery
warn us not to draw any conclusions about what happens
inside a Thevenin equivalent source so your specification
must be an achievable well-defined real-world source.
How about a class-A linear amplifier with no filters,
no impedance transformation, and no protection circuitry?
Vrms/Irms = 75 ohms Vrms*Irms*cos(0) = 1 watt

The amount of interference cannot be calculated without
magnitude and phase. Shall we assume that the 450 ohm
line is an integer number of wavelengths and lossless?
i.e. Z0-matched to 75 ohms?

If you require detailed calculations, more specified
information is needed.
--
73, Cecil http://www.w5dxp.com