开云体育

Hi

It's not a spur at all, its the zero (or dc) part of the spectrum that
the sound card is processing. (and thus will be at the center of the
display (because of the way the I/Q is processed) regardless of the
SR40.

From my measurment when the SR40 is working it gets -40dbm signal to
the antenna.(at the 7.056 Mhz) and very little at twice thrice and at
28.224Mhz

73 de Joe

--- In softrock40@..., windy10605@j... wrote:

What generates the nice 7.054- 7.056Mhz signal on the computer (PowerSDR
or Rocky) when the SR-40 is not installed ? Excellent choice for the
crystal freq, by the way. No sense having 2 large spurs. I realize there
are going to be small spurs because of the inherent nature of computer
clocking and signal transition radiations.

I'm not surrounded by SR-40 users but out of curiosity, how much of the
OSC does it put OUT into the antenna ?

73 Kees K5BCQ

You got me curious now.

When I put the sf40 next to the antenna tuner I get a nice s7
@7.054.26 with the tuner hooked to the radio (857) and another s9 sig
from my network switch at 7.053.36. The computers (3) don't seem to
be radiating any noise... In this particular section of the band.

I look forward to getting all my projects in boxes during my upcomming
break.

Chris N7UJU