QYT KT8900 PACKET MOD
by rfeigenblatt in Circuits > Electronics
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QYT KT8900 PACKET MOD
QYT KT8900 mod for PACKET
This is a chinese cheap 20W 144/440MHz mobile radio, but have two wrong design thinks to connect friendly this unit with your sound card because them not have a external speaker jack, also the squelch operation is too slow.
A good idea is take the audio signal from the discriminator directly, here you have a opensql signal, a clean and good quality and audio signal.
To make this modification please use the ht9170d chip (used to decode a DTMF signaling) also use empty pin 8 on the mic connector with a 2,2uf electrolitic capacitor to audio coppling.
Open the Radio to See the Main Board, and Back Display Board Too.
Locate the Ht9170d Chip on the Main Board, Near to Conecctor to Display Board
Locate the Mic Conector Exclusive Pin 8 and Install a Wire From This Pin to Ht9170d Chip
Install One End of the 2,2uf Electrolitic Capacitor on Pin # 2 Ht9170d Chip (vn Pin) and Another Capacitor End to Wire From the Pin 8 of the Mic Connector
The Mod Is Done!, Now You KT8900 Have a Audio Signal From the Discriminator on the Pin #8 (mic Connector)
Reesamble your radio and make wires to your PC Sound card
The signal is clean and strong to your audio input on the sound card
Enjoy! 73
TI2BOX