Check the listing for details. PiHat Ham Radio PTT Trigger/Isolator Board for Raspberry Pi. Condition: New. Listed at 1.50 USD. PiHat Ham Radio PTT Trigger/Isolator Board for Raspberry Pi. Part #: HTX-PTT1b-PCB • Use for keying Radio's PTT from Raspberry Pi • GREAT for WSJTX/FT8 and all other digital modes • Single-row, 6-pin connection to rPi (ODD Pins 1-11) • Uses GPIO17 as Serial Port's RTS (Mode ALT3) as controlled by WSJTX • Uses 4N25/4N25M opto-coupler (install with pin 1 near resistor) • Use Optional 1nF capacitor (pads on board) for RF blocking • Shared ground-plane between radio and Raspberry Pi • Must be forward current from Radio's PTT line into board (ensure GND is correct) • Schematic included (see photos)• Check out other models at: https://www.ebay.com/itm/164818533353 https://www.ebay.com/itm/164818573371 https://www.ebay.com/itm/164924631970 https://www.ebay.com/itm/164924569202 BOARD ONLY - No parts included. Pictures with parts and Raspberry Pi are for reference only. Condition is "New". Shipped with USPS First Class.