Hi John,
The main reason one might buy a BB60A now is due to price. We do not sell the BB60A anymore and have not since the BB60C was released.
The BB60C hardware design is drastically different than the BB60A, as you noted. The BB60C uses a direct RF path for frequencies below 20MHz. The HDSDR application requires an input I/Q data stream to operate on. We have not developed the direct RF to I/Q code necessary for HDSDR. This only affects 20MHz and below. Our API is available to users and we do provide the code for our device to interface HDSDR, so if you have programming experience, it would be possible to fill in the missing pieces to get the direct RF into HDSDR. This would require C++ and signal processing experience.
Regards,
A.J.
