25-pin Transceiver Connector on the rear panel of RigExpert Interfaces

Pin

Pin name

Comment

1

FSK_OC

FSK open-collector output

14

FSK_PULLUP

Pullup to +5V through 4.7K resistor

2

DIT

CW paddle input (dit), shorten to ground – RigExpert Plus/TI-5 only

15

DAH

CW paddle input (dah), shorten to ground – RigExpert Plus/TI-5 only

3

VCC

+5V output (USB power line)

16

PTT5V

TTL-level PTT output (5V in transmit, 0V in receive mode)

4

CW_OC

Open-collector CW output

17

PTT_OC

Open-collector PTT output

5

DCD

DCD (squelch) input

18

12V_MAX

+12V output (generated by MAX232 chip)

6

SPK_TRCVR2

Transceiver audio output (speaker), sub receiver

19

RXD_OE

Serial input (5V levels), connect RXD5V to VCC to activate this input

7

CIV_IN

CI-V input (ICOM transceivers), pulled up to 12V_TRCVR with 4.7K

20

12V_TRCVR

Connect to VCC to power the CIV_IN input

8

CIV_OUT

CI-V open-collector output (ICOM transceivers), connect to CIV_IN

21

CO_PULLUP

Pullup to +5V through 4.7K resistor

9

TXD12V

RS-232-compatible serial output (±12V levels)

22

RXD12V

RS-232-compatible serial input (±12V levels)

10

TXD5V

Serial output (5V levels)

23

RXD5V

Serial input (5V levels)

11

GND

Digital ground

24

GND

Digital ground

12

SPK_TRCVR

Transceiver audio output (speaker)

25

MIC_TRCVR

Transceiver audio input (microphone)

13

AGND_TRCVR

Audio signal ground

Audio in/out:

  1. SPK_TRCVR is connected to the transceiver speaker (or line out) output.
  2. SPK_TRCVR is connected to the transceiver speaker (or line out) output for the sub receiver (if available).
  3. MIC_TRCVR is connected to the transceiver microphone (or line in) input.
  4. AGND_TRCVR is connected to the transceiver ground (connection point should be as close to the transceiver as possible).

RigExpert interfaces decouple audio in/out signals from computer signals using transformers, which prevents interference caused by parasitic current in grounding.

FSK output:

FSK_OC is an open-collector output, sinking 50mA maximum (using BC817 NPN transistor). Connect this pin to FSK_PULLUP to obtain the TTL-level output.

PTT and CW outputs:

PTT_OC and CW_OC are open-collector outputs, sinking 50mA maximum (using BC817 NPN transistors). PTT5V is a TTL-level PTT output (5V in transmit, 0V in receive mode), output current is 5mA maximum.

CW paddle inputs:

DIT and DAH are CW paddle inputs (single or double paddle for yambic keying), pulled up to +5V with 4.7K resistors.

Serial in/out:

RigExpert interfaces provide various methods of connecting serial in/out lines with different signal levels to the virtually any model of transceiver. This only requires shortening some pins on the RigExpert transceiver connector.

  • RS-232-compatible mode uses TXD12V and RXD12V lines with ±12V signal levels, provided by MAX232 interface chip.
  • CI-V mode uses CIV_IN and CIV_OUT lines (should be shortened together). CIV_IN is internally pulled up with 4.7K resistor to 12V_TRCVR, which should be connected to VCC.
  • TTL-level (5V) mode uses TXD5V and RXD5V lines. Signal polarity is opposite to RS-232 mode.
  • Yet another TTL-level mode (signal polarity is the same as with RS-232 mode) uses CIV_OUT output (should be connected to CO_PULLUP) and CIV_IN input (12V_TRCVR line should be connected to the VCC output). It is better to use RXD_OE input in this mode (RXD5V should be connected to VCC to activate this input).