LoneStar SemiConductor Designs

These are the pass bands on the TX filter and RX filter of the MMDVM boards. The top is the TX and the bottom the RX filter. Notice there is less than 3dB of attenuation at the target frequency.

I made these with my shiny new Spectrum Analyzer / Vector Network Analyzer

Looks legit!

Well I have some good news! I received today from Avnet 250 of the STM32F103 microcontrollers. This is what has had me out of business. So hopefully within the first few weeks of the new year I can have another LOT of Duplex modems in process.