LQ / FOR-22 to Motorola APX 7500

Here is an untested pinout for connecting to the APX:

Headset 1 J11 and/or Headset 2 J12 (DB9 to RJ45)

APX 7500 J11/J12 Pin

Purpose

LQ Pin

LQ Purpose

APX 7500 J11/J12 Pin

Purpose

LQ Pin

LQ Purpose

2

Headset Detect

Short to APX pin 8

Active Low - tying to ground

3

Speaker -

2

Audio In -

4

Microphone -

1

Audio Out -

5

Microphone +

6

Audio Out +

6

PTT

5

Relay Normally Open

7

Speaker +

7

Audio In +

8

Ground

9

Relay Common / Wiper

Crosspatch J24 (DB9 to RJ45)

APX 7500 J24 Pin

Purpose

LQ Pin

LQ Purpose

APX 7500 J24 Pin

Purpose

LQ Pin

LQ Purpose

1

Receive Audio

2

Audio In +

2

Channel Activity

3

Logic Input

3

Ground

6,7, 9

Output and Input Ground, plus Relay Common / Wiper

7

PTT

5

Relay Normally Open

8

 

1

Audio Out +


Accessory 1 J104 (DB25):

URC-200 J2 Pin

Purpose

LQ Pin

LQ Purpose

URC-200 J2 Pin

Purpose

LQ Pin

LQ Purpose

2

Ground

6, 7, 9

Output and Input Ground, plus Relay Common / Wiper

4

RX Audio

2

Audio In +

10

PTT

5

Relay Normally Open

17

TX Audio

1

Audio Out +

25

Channel Active

3

GPI / COR