David N8DAH from Kit-Projects.com will have BCI kits out in the next week or so for the BitX radios as well as other direct conversion receivers that suffer from close AM stations.
The drop off of the filter kit is right at about 3MHz.
These filters will cost 5$+ shipping. They come with 3x toroids and 4x capacitors. This would be a good kit to learn about toroid construction for those that have not had a chance as yet to try winding your own.
These filters are RX ONLY and should not be placed in the TX path.
David’s website will have detailed specifications and instructions for both the Bitx40 and uBitx radios on it shortly.