[th0ma5]

Yeah I think most big name radio producers see amateur sales as a secondary market. There are some hobby projects like the uBitx and the mcHF, and both are low power. The amplification and filtering are in opposition to dynamic range and total power output. For instance without filtering, a very strong signal will blow out the dynamic range and quieter signals will get lost. If you say were to build a ZetaSDR and plug it into a 192khz 24bit sound card, you would have excellent dynamic range for weak signals, but you'd still want to filter out local FM and AM stations.

I think as more SDR stuff gets reduced to single chips for commerical or military reasons, then perhaps the amateur equivalent will be viable... But filtering and amplification is still something that is difficult to miniaturize due to heat and wavelength.