Qyt Kt8900 Programming Cable Pinout Top Now

The QYT KT-8900 uses an 8P8C connector (looks like RJ-45).

If you look at the radio’s front, you’ll see a 6-pin modular jack (RJ-12 style for the mic) and an 8-pin jack. The programming port is the 8-pin one.

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. qyt kt8900 programming cable pinout top

| Symptom | Likely Pinout Issue | Fix | |---------|--------------------|-----| | "Radio not found" | Pin 2/3 swapped, or GND missing | Swap TX/RX; check Pin 1 continuity | | Timeout after reading 1% | +5V on Pin 6 is missing | Bridge +5V from USB adapter (if ≤100mA) | | Garbage characters in terminal | Incorrect baud rate | Ensure 9600, 8N1, no flow control | | Radio resets when plugging cable | GND loop or 5V short | Add a 100Ω resistor on Pin 6 |

If you have the pinout correct (or bought a supposedly compatible cable) and the radio is still refusing to write or read, check these three critical points: The QYT KT-8900 uses an 8P8C connector (looks like RJ-45)

For data programming only (no firmware flashing), you only need three pins:

In most commercial QYT programming cables, the USB-to-TTL chip (like the CP2102 or FT232RL) connects directly to pins 4 and 5. Pin 3 provides the ground reference. If you look at the radio’s front, you’ll

Pin 2 (+5V) is sometimes used to power the USB-TTL adapter if you are making a custom cable, but do not feed +5V from the radio into a standard USB port—you’ll damage your computer.

Before you power on the radio and attempt to read the frequency data, verify: