| USB-to-TTL Adapter | → | RJ-45 Pin (Top/Radio) | |--------------------|----|----------------------| | GND | → | Pin 3 | | TX (from adapter) | → | Pin 5 (Radio RX) | | RX (to adapter) | → | Pin 4 (Radio TX) |
: The programming jack on the back of the KT-8900 is often recessed into the case. Standard bulky 3.5mm plugs may not fit; use a "slim" style connector or a repurposed PC speaker cable for a better fit. Software Setup qyt kt8900 programming cable pinout top
| Pin # | Signal | Wire Color (typical in pre-made cables) | |-------|--------|------------------------------------------| | 1 | NC | (Not connected) | | 2 | +5V | Red | | 3 | GND | Black | | 4 | TX (Radio transmit → PC receive) | Green | | 5 | RX (PC transmit → Radio receive) | White | | 6 | GND | Black (sometimes bridged with pin 3) | | 7 | Audio out to radio (speaker) | Yellow | | 8 | PTT / Mic ground | Brown | | USB-to-TTL Adapter | → | RJ-45 Pin