SDRMAXII Banner

tutorial early versions interference modifications other stuff

My QS1R is an early Revision C board. Only one modification has been necessary, which was to fit a 100nF capacitor across L1. This greatly reduced the interference I was seeing at 8kHz spacing. Some before and after screenshots below.

Larger versions of these pictures are not available.

without at 2MHz after at 2MHz
before at 2.28MHz after at 2.28MHz
before at 2.382MHz after at 2.382MHz
before at 2.888MHz after at 2.888MHz
before at 3.684MHz after at 3.684MHz
before at 3.995MHz after at 3.995MHz
before at 7.05MHz after at 7.05MHz

All of the above were with QS1R Server running on an old laptop and SDRMAXII running on my main PC. These last two pairs show the differences before and after, with both the server and GUI running on my desktop PC. The interference was much worse with that setup.

before at 3.5MHz after at 3.5MHz
before at 7.05MHz after at 7.05MHz

Go to top of this page.

Valid HTML 4.01 Transitional