Qyt Kt8900 Programming Cable - Pinout Top
The programming cable for the QYT KT-8900 3.5mm TRS (stereo) audio jack
that connects to the "DATA" port on the back of the radio. Unlike many handheld radios that use dual-pin connectors, this mobile rig relies on a simple three-wire serial interface for data transfer. 🛠️ Programming Cable Pinout (3.5mm Plug) qyt kt8900 programming cable pinout top
While some "DATA" ports use 4-pole (TRRS) plugs, the standard KT-8900 programming connection typically only requires three contacts: RX (Data from Radio to PC) TX (Data from PC to Radio) Ground (GND) Digirig Forum The programming cable for the QYT KT-8900 3
Note: If using a USB-to-TTL adapter (like a CP2102), ensure your TX wire connects to the radio's RX pin and vice versa. 🎤 Microphone Port Pinout (RJ45) If you are looking to interface with the front RJ45 microphone port for other projects, here is the standard layout: QYT Radios Description Data Input Auxiliary data Repeater control Microphone audio input MIC Ground Ground for audio Push-to-Talk Main chassis ground +8V DC Out Low current power for mic Not connected ⚠️ Pro-Tips for Successful Programming My cable works, but only if I flip
Complete Wiring to USB (PC side)
Inside the programming cable, the two plugs are wired to a USB-to-TTL serial adapter (often a Prolific PL2303 or CH340 chip):
- 3.5mm Tip → USB TTL RX (radio transmits data → PC receives)
- 2.5mm Tip → USB TTL TX (PC transmits → radio receives)
- Both Sleeves → USB TTL GND
My cable works, but only if I flip the RJ-45 plug upside down. Why?
You have a mirrored pinout. Flipping the plug swaps pins 1 and 8. That means your cable is wired opposite: Pin 8 is GND. This is non-standard; re-crimp properly.