22
MDS 4790/9790 Series I/O Guide
MDS 05-3438A01, Rev. F
Invisible place holder
Figure 19. Diagnostics Port Connector, J1
4-Wire Audio Connector—J2
J2 is a plug-in terminal strip that provides connections for 4-wire audio
circuits.
Figure 20
shows the function of each terminal as viewed from
the rear panel.
Terminals 1 and 2 are for transmit audio input with a nominal 600
Ω
impedance. Terminals 3 and 4 provide a receive audio output with a
nominal 600
Ω
impedance. Pins 5 and 6 provide an external keying
source. Shorting pins 5 and 6 keys the radio.
Refer to
Figure 22 on Page 24
for information on connecting the radio
to a VOX assembly.
Figure 20. 4-Wire Audio Connector, J2
PIN 2— RXD
PIN 3— TXD
PIN 4— +5 Vdc
PIN 5— GROUND
PIN 7— RTS*
* Used when reprogramming the radio firmware with a PC.
UNUSED
UNUSED
UNUSED
UNUSED
RECEIVE AUDIO
600 OHM
4
1
2
3
5
6
TRANSMIT AUDIO
600 OHM
EXTERNAL KEYLINE
(GROUND TO KEY RADIO)
RSPSupply - 1-888-532-2706 - www.RSPSupply.com
http://www.RSPSupply.com/p-8457-MDS-UP-9790X.aspx