Qyt Kt8900 Programming Cable Pinout Top [cracked] Jun 2026
When choosing an interface or building your own, consider the hardware variations:
Splice your cable and track the continuity using a digital multimeter. Connect the individual lines directly to the pins on your USB-to-TTL interface as follows:
: Install the appropriate drivers for your specific USB-TTL chipset before plugging in the cable.
| TTL Adapter Side | 3.5mm Plug Side (Radio) | | :--- | :--- | | TX (Transmit Data) | Tip (TX) | | RX (Receive Data) | Ring (RX) | | GND (Ground) | Sleeve (GND) |
: TXD (Transmit Data) — Sends data out from the radio to the PC. qyt kt8900 programming cable pinout top
Unscrew the plastic shield of the 3.5mm plug and slide it onto your cable wire before soldering.
Once you have installed the software, connect your KT8900 to your computer using the programming cable. Configure the software to use the correct COM port and baud rate (typically 9600 bps).
| Pin Number | Signal Name | Wire Color (Typical in OEM Cable) | Function | | :---: | :---: | :---: | :---: | | | NC / GND | Black | Not connected in programming mode (ground on some versions) | | Pin 2 | SPK- (Speaker -) | Yellow | Negative speaker line (not used for programming) | | Pin 3 | MIC / TXD | Blue | Programming Transmit Data (Radio → PC) | | Pin 4 | PTT | Green | Not used during programming | | Pin 5 | GND | Brown | System Ground (critical for programming) | | Pin 6 | RXD | Red | Programming Receive Data (PC → Radio) | | Pin 7 | VCC / 5V | Orange | +5V power from radio (only active when radio is ON) | | Pin 8 | SPK+ (Speaker +) | White | Positive speaker line (not used for programming) |
Note: On some KT-8900 variants, the specific function of the PTT and Data lines can be bridged internally within the cable. This is why "homemade" cables often fail—the radio expects a specific resistance or bridging configuration on the data lines to recognize a programming session versus a speaker-mic session. When choosing an interface or building your own,
Before building a cable, it's crucial to understand the different ports on the radio and which ones to use for programming. The radio uses 3.5mm jacks for programming, not the microphone port. Here's a breakdown:
You cannot wire a 3.5mm plug directly into a standard USB cable. Doing so exposes the radio's logic board to 5V power lines, which can permanently fry the data chip. The cable must pass through a .
The manual programming process is tedious and error-prone. The solution is to use computer software to quickly upload or download channel lists. The most recommended software is CHIRP , a free, cross-platform tool that is simpler and more powerful than the manufacturer's own software. To use it, you must connect your radio to your PC via a specialized programming cable.
By default, software programs might default to COM1 or COM2 . USB-to-serial chips almost always register as COM3 or higher. Ensure the port selected matches your Device Manager assignment. Unscrew the plastic shield of the 3
As you can see, even among Chinese radios using RJ-45, the pinout varies. The KT-8900’s configuration (with Pin 3 as TXD and Pin 6 as RXD) is unique to the QYT KT-8900, KT-8900D, and KT-UV980. Do not assume compatibility with any other radio.
Open CHIRP (Free Open-Source Radio Software) or the official QYT KT8900 Programming Software .
If you are DIY-ing a cable using a standard USB-to-TTL serial adapter (like an FTDI or CH340 board), the connections to the 3.5mm plug are as follows: RX (Data Receive) TX (Data Transmit) GND (Ground) Digirig Forum Note on Connector Fit: