Re: [softrock40] SR V7 mixer and QSD (Was: Re: Radiated emissions?
- Hi,yes, I was driving my unit with a pair of HP8640Bs through a homebrew combiner. I watched the spectrum display for a 3 dB spur coming out of the noise floor on the screen. My sound card was stock Dell 1 GHz machine. so nothing special. The noise from the generator may have effected the close in. My LO is a color burst crystal divided down by 8. So it should be clean. You would think the IMD would be the same at any spacing. Even Flex has different numbers close/wide spacing. Frank
Marco <ik1odo@...> wrote:At 15.03 30/01/2007, you wrote:
>I measured 3253 dynamic range around 84 dB at 2 KHz spacing using a
>stock Dell sound card. At 20 KHz spacing 95 dB. MDS was around -130
>dBM at 80 meters.
>I think it would be better with a better sound card.
>The 3253 was configured as a double balanced Tayloe INA163s for
>amps. Frank WA1GFZ
are you talking about IMD3 dynamic range?
In this case, why the figures change with the signal spacing? Where
you limited by the signal generator noise sidebands, ot other things?
73 - Marco IK1ODO