ab7r wrote:
While I had not yet solved all the spurs showing up on my display...about
every 1Khz on 10m, I decided to update my system RAM from 512M to 2Gb. Very
nice difference on system operation....all except for the SDR.
When I turned it on, all of a sudden all the LSB signals were unintelligible
and had to be tuned in on USB. I would click on an obvious LSB signal to
get it into the passband and it would then disappear.
So I say to myself...maybe something happened and I should recalibrate.
Broke out my trusty XG-1 that worked fine before.
I tuned into the peak near 7.040 and calibrated the freq. With the new
RAM...this took all of about 3 seconds. I then recalibrated the noise
floor. Now my noise floor is at -100db instead of -135 where it was before.
This also went very fast. So then I recalibrated the signal
again....still -100db. Tried to calibrate the image....got an error message
saying it failed.
I'm having that problem (high noise floor) with my Extigy.
Some of this may be sound card specific (despite other factors being
present). On the very same hardware, my Extigy is having maybe a 30 to
50 dB higher "noise floor" than the D44.
But, whether that's a real noise difference or simply a calibration
problem is not clear as I can't easily compare them "live."
Larry WO0Z
