Can you tell us the manufacturer and part numbers for the front-end filter inductors? I'm interested in looking at them in terms of Q. I've tried to find chip inductors that would work in this type of filter, but none were really satisfactory in terms of Q.
Have you experienced any microphonics with this board? DC receivers are notorious for exhibiting microphonics when surface mount ceramic caps are used.
One improvement (arguably) over the Softrock receiver in my opinion would be the inclusion of a pre-amplifier. Not that gain is needed, but a pre-amplifier will present a consistent match to the mixer. Both the gain and bandwidth of DC commutating mixers depends highly on the antenna match. Having a 9:1 or-so unun on the preamp input would also facilitate use of a long-wire antenna.
Thanks, David WB4ONA
--- In email@example.com, "boydsoftprez" <boydsoftprez@...> wrote:
> Hello all,
> I would like to introduce our new SDR inspired by the softrock. Thanks for your consideration and comments. We are hoping to put together a much larger order and have many of them stamped out. All we need is your help.
> Fully assembled and tested.
> Precision inductors, coils, and transformers for consistent high quality.
> Additional ESD filtering on the antenna input.
> Low-profile Mini-USB connector.
> USB powered eliminating potential ground loops.
> Audio crossover switch to swap left and right channels.
> User configurable grounding and isolation schemes.
> LED band indicators.
> Dimensions: 3.5In x 2.25In
> BNC antenna connector 50 or 450 Ohms
> 4-Layer PCB resulting in superior ground plane
> Continuous coverage 1.8Mhz-30MHz
> 160 Meters (1.8-2.0 MHz)
> 80 Meters (3.5-4.0 MHz)
> 40 Meters (7.0-7.3 MHz)
> 30 Meters (10.1-10.15 MHz)
> 20 Meters (14.0-14.35 MHz)
> 10 Meters (28-29.7 MHz)