Recent content by Rudibot

I'm a bit rusty.. I have a cosine y = cos(2*pi*f*t) If I want to advance the cosine by say 90 degrees y = cos(2*pi*f*t + pi/2) but.. this waveform has f cycles per 2*pi*t..so won't I be advancing the phase by f*pi/2? someone pls straigthen me out - I'm working with Matlab indexes and...

"Ummmm, I think you are confusing something. A receiver that cannot select out one of the signals (100 Khz and 110 Khz) is just a receiver that is lacking in selectivity (narrow filtering). It has nothing to do with a spec-an." Of course. My point being that what you see on the specan may not...

OK I am feeling more comfortable with this now. While it is fine to talk about infinitley small bandwidths in reality no equipment or receiver can achive this so in effect it does not exist - it is just a mind experiment. So to take an accurate spurious measurement you need to consider the...

Thanks f95toli, that will give me a direction to go with. dillonjerry, I am sure this is not true. Bandwidth of signals - and in this example the separation of the spurious signals is conserved in an up or downconversion process. If this were not the case I would be able to compress the...

I'm not sure downconversion would expand the signal - just shift it downfrequency in which case I woud have the same experiment just at a lower frequency - same bandwidth.

I would have thought it had a very sharp top? There would only be an instant when both signals are inside the filter bandwidth - the rest of the time it would encompass only one signal on each side and be flat. Regardless, I will change the question to 10 equal power spurious within 1Hz. I...

Just some background - I am trying to measure spurious radio signals around a carrier in dBc units. It seems easy until you consider the resoultion bandwidth you are going to set your specan up with. If you start with a large bandwidth the spurious signals can get mixed up with the carrier and...

Thanks vanesch, so p=k*t*b is the real power. p=4*k*t*r*b is the signal power. But if the power is independent of conductor length, what is to stop me from cutting a conductor into *infininte* (read lots) of peices and getting lots of power?

Thanks Bob, Sowhy do we need the relationship P = 4.k.t.R.B If we already know the power in the circuit?

The noise power in a conductor is given by P = k.t.B Does this mean the noise power is independant of the conductor length? Also, does this only apply for a conductor with no resistance? Thnks, Rudi