This is a redesign of the standard SIMPLEX board I've been selling.   I keep making improvements to the layout.   That brings the current revision to 1V8-2.    I took the design practices of the DUPLEX board that enable it to work so well and ported them over to the SIMPLEX board.    For example this board has its own dedicated 3.3V regulator and does not pull voltage off of the noisy Raspberry Pi 3.3V line like all other simplex board do.    This board is now a 4 layer board with LARGE ground planes for 3.3V and GND sandwiched in the middle.   This acts as one very large decoupling cap the size of the entire board.   Also this isolates signals between TOP side and BOTTOM side.    Speaking of that all of the Analog RF signals are on the TOP side only and the high harmonic digital signals are all kept isolated on the BOTTOM side.   Making this board much more stable.   It should also make it more sensative on receive.   

This board fully supports an OLED screen and the Nextion screen.    It comes with a 432MHz ceramic antenna mounted on the board.   But if you prefer you can dismount this antenna and install an SMA connector in order to install a standard antenna with some gain.


I find however the ceramic antenna is well more than enough when the HOTSPOT is in the shack with me or riding along beside me in the truck.


MMDVM Simplex ( 1V8 )

  • If you have questions you can find some answers here on N5BOC.COM


International Shipments:
Due to COVID-19 , international shipments are seeing delays as they pass through customs.   Shipments that normally take 15 days can presently take as much as 10 weeks.  But this is the exception.   The average time appears to be around 4 weeks right now.    But please don't become discouraged if your shipment takes much longer.   

Thanks:  David