Amateur Radio

QYT KT800 & KT8900D and variants X-band repeater system interface

QYT KT8900 and QYT KT8900D Repeater system

QTY KT8900 and QYT KT8900D chinese radios and variants have a built in repeater function that works out of the box without additional modification on the radio. You just need to enable the repeater function (cross band repeater VHF/UHF or UHF/VHF) via the menu system. Connect the two radios via the mic port using the cable shown here and enable the repeater function on the radio. The radios will work in the repeater mode cross band and will re-transmit your audio either on the VHF or UHF and vice versa.


Download the PDF document here for repeater interface

The repeater interface will work on the variants of these radios in either combination of at least 2 KT8900 RX/TX,
2 KT8900D RX/TX or 1 KT8900 and 1 KT900D and of course Baofeng Tech radios. The configuration is done on individual radios by setting the REP-M (Repeater transponder function on both radio). Once a matched Carrier, CTCSS/DCS, TONE or DTMF is received in either of the radios it will re-transmit the audio on the other radio and vice versa.

QYT KT8900 and KT8900D Repeater System
QYT KT8900 and KT8900D Repeater System

Build the cable

Do it yourself using RJ45 modular connector and a piece of LAN UTP cable

DIY X-Band Repeater Cable for KT8900 and 8900D and variants
DIY X-Band Repeater Cable for KT8900 and 8900D and variants

Finished Cross Band X-Band repeater interface

Finished X-Band (Cross Band) repeater cable
Finished X-Band (Cross Band) repeater cable

Let’s see how it works

Testing video of working repeater system


1. Easy deployment for field work to extend portable radio range with acceptable results
2. Will fit easily in a go box
3. Inexpensive but it works


1. Recommended for light usage as QYT Radios tend to heat up easily
2. Use the upgraded version of QYT the KT8900D for more stability
3. Suitable only for Cross Band configuration
3. KT 8900 heats up like a barbecue grill if it didn’t burn your finals at least bring a hotdog to grill …


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