Summary
The preamplifier was a complete success in the control of volume and mute. Simple control via remote. Low distortion performance.
Though providing excellent control of tone across the audio band, the distortion created through the use of the digital potentiometers, though likely completely inaudible, did not allow performance to reach the goal of less than .01%, instead reaching .0275%.
The chosen antenna (simple quarter wire at quarter wavelength of 433MHz) was inadequate. A proper chassis mount antenna is needed if distances of remote-preamp communications of 100 feet or more are to be realized.
Estimated BOM for quantity 1000, made locally in the USA, was $229. This could be reduced significantly, if outsourced overseas.
Though providing excellent control of tone across the audio band, the distortion created through the use of the digital potentiometers, though likely completely inaudible, did not allow performance to reach the goal of less than .01%, instead reaching .0275%.
The chosen antenna (simple quarter wire at quarter wavelength of 433MHz) was inadequate. A proper chassis mount antenna is needed if distances of remote-preamp communications of 100 feet or more are to be realized.
Estimated BOM for quantity 1000, made locally in the USA, was $229. This could be reduced significantly, if outsourced overseas.
