[Lowfer] Re: 185.3 party tonight!

[Alberto di Bene]

Jay Rusgrove wrote:

>  If I paint a constant line on Argo with the
> signal generator output fixed at a level 20 - 30 dB out of the noise (visual background
> noise of Argo - the "snowstorm") and drag the cursor across that line I see up to a couple
> dB variation even if I stay in the solid white area of the line. I know this 2 dB is not
> from the signal generator/attenuator so I am left to assume that this must be an issue of
> noise, receiver or sound card problems.

I suppose that the variations are to be accounted to the noise components falling in
that frequency slot, which are not constant in time.
That's a different measure from what was performed on Spectran.
We injected the audio signal from the generator into the sound card, placed the peak in
the middle of the screen, and noted the agreement (or lack of) between the output dB
meter of the Rohde & Schwartz generator and what Spectran reported, when we
varied the output level of the generator.
A measure under ideal conditions, different from what is encountered in practice...

73  Alberto  I2PHD