Features:

Repeater and Simplex mode change anytime , through change the RX/TX board line order.
Support MMDVM mode DMR/YSF/P25/NXDN/DSTAR/POCSAG, Analog (Just work in some Motorola GM340 or GMxx serial)
Double timeslots in DMR mode, act as a mini Digital voice repeater.
Support VHF/UFH, frequency range:  depends on your external radio.
High-quality Fox924B 12MHz TCXO, stable with low BER.
Support Raspberry Pi 3B, 3B+, 3A, 4B, Pi ZERO(W), , Compatible with NanoPi NEO, Orange Pi, Compatible to BlueDV(Required to add USBtoTTL or Bluetooth model)
With USB interface ,can connect to Raspberry Pi and PC, inner PL2303 model.
Upgrade through ST-Link, USB, GPIO, continue upgrade support.

Including && components
1x PCB with complete soldering,
1x External radio connector cable  

Specs and Docs:
Power require: 5V2A
MCU: STM32F446x
TCXO: 12.0MHz ,FOX924
HAT: 1.6mm thick, unleaded process
Interface: MicroUSB, GPIO, DB9 female, 6 PinOut
 
Technical support: bi7jta@gmail.com , www.facebook.com/winters.cn

Microsoft Teams, TeamViewer, Facebook IM, Telegram, WhatsApp.

Payment : PayPal 

Setting guide

https://www.bi7jta.org/wik

• 2.5Repeater Board
  • 2.5.1Importance Process: Calibration Frequency Offset
  • 2.5.2Simplex and Repeater diagram (Motorola 16 Pins and 20 Pins)
  • 2.5.3V3F4 Pinout define
  • 2.5.4COS LED bright means RX and TX work (in Duplex/repeater mode)
  • 2.5.5FT-7900/7800/8900 YAESU
  • 2.5.6FT-817/991/857D
  • 2.5.7FTM-100D/FTM-350
  • 2.5.8DR-1X YAESU
  • 2.5.9GM3188/GM3688/CM140/CM340
  • 2.5.10GM338-CDM1250-CDM1550-CDM750-MCX760
  • 2.5.11ICOM IC-208H
  • 2.5.12GM300/M120 Motorola
  • 2.5.13SM50/SM120
  • 2.5.14GM340/GM350/GM360
  • 2.5.15GM950i Motorola
  • 2.5.16Kenwood TK8180
  • 2.5.17Kenwood TM-451E
  • 2.5.18Kenwood TKR750/850
  • 2.5.19XPR4550/M8268/XPR5550e DMR serial radio
  • 2.5.20XiR M3188/XiR M3688 DMR radio
  • 2.5.21Data radio FC302
  • 2.5.22MTR2000 Motorola
  • 2.5.23MCS2000
  • 2.5.24RadioCPS DMR radio templates
  • 2.5.25FM Analog mode
  • 2.5.26Upgrade firmware
  • 2.5.27Troubleshooting Possible Error
  • 2.5.28Compile firmware
  • 2.5.29Adjust TX Level with SDR
  • 2.5.30Adjust RX Level with MMDVMCal
  • 2.5.31Adjust RSSI Potentiometer

DIY project, not support  unconditional returns, please make sure you have enough patience to use this set of open source development kit, have question you can contact bi7jta@gmail.com ,I will use Remote desktop: Teamviewer, Microsoft Teams, help you make it work, if necessary.

Support Digital mode DMR/YSF/P25/NXDN/DSTAR/POCSAG/FM Analog

NOTE:

1) If you choose Only_HAT item, it is not including Raspberry Pi , you can use Raspberry Pi ZeroW, 3B, 4B, or Windows PC.

2) If you select MCS2000/TK8180/8185 DB25 cable , I will make a SIMPLEX cable link to one radio, you can soldering and use in DUPLEX two radios.

3) Please let me know your repeater radio you will link to this board , I will adjust the TXLevel for you , otherwise you need a RTL-SDR or spectrum analysizer,  I will help you by Microsoft Teams or Teamviewer.

The components I can provide , click the photo to view big image.

Facebook group https://www.facebook.com/groups/v3f446  (add me as IM friend query more information)

Youtube  https://www.youtube.com/wintershuang

Build up with higher performance components

STM32F446,

FOX924B 12MHz TCXO,

DB9 interface,

4PIN header for Nextion .

With DB9 cable (option 0.5/0.75/1.0/1.5 Meter)

User cases:

Motorola GM338/GM340/CDM1250/CDM1550/CDM750/MCX760

Motorola MTR2000

Yaesu DR-1X (not work with DR-1XFR, DR-2X)

Yaesu FT-7800, FT-7900, FT-8900, iCOM-2720

Motorola GM300/M120

Motorola SM120, SM50

Motorola MCS2000

Tait repeater serial, HUAWEI E403, HUAWEI 450C

FC302 Data radio

Use SDR#(RTL-SDR) or Radio analylzer (such as CMU200) to view and adjust the TXLevel for you different repeater radio.

Use spectrum analyzer, eg. CMU200

SDRPlay + SDRuno adjust TXLevel

The board details,

Shipping components list

V3F4 Definition

1, Radio Data

Transmitter radio
TXA
PTT
GND

Receiver radio
RXA
RSSI
GND

Extend
HB heartbeat

Cancel
COS

2, Nextion
5V <-> HAT 5V
RXD <-> HAT TX
TXD <-> HAT RX
GND <-> HAT G

3, OLED
V3F4 Cancel OLED interface, please follow Raspberry GPIO definition, and jump line yourself.
http://mmdvm.bi7jta.org/search/label/Definition_GPIO_PCB_Case

4, Potentiometer ( High-precision )
RX : Adjust RX level
RV2: Secondary adjustment, suggest keep default
TX : Adjust TX level
RSSI: extend

5, External LED
J7 : Connect external led
J8 : Open,GND for external LED