MFJ-1272B
Instruction Manual
5
Audio Out Connection
Table 3 below shows where you would place a jumper, depending on what
microphone pin is designated MICROPHONE AUDIO. The microphone pin,
designated MICROPHONE AUDIO, is the where the transmit audio from the TNC
comes into the radio. For example, if MICROPHONE AUDIO is designated pin 1
on a Kenwood microphone, then you would place a jumper on position R1C in the
AUDIO OUT section of header HD1.
Radio MIC Pin
MFJ-1272B
Header
Place a jumper on:
1
HD1
AUDIO OUT--R1C
2
HD1
AUDIO OUT--R2C
3
HD1
AUDIO OUT--R3C
4
HD1
AUDIO OUT--R4C
5
HD1
AUDIO OUT--R5C
6
HD1
AUDIO OUT--R6C
7
HD1
AUDIO OUT--R7C
8
HD1
AUDIO OUT--R8C
Table 3
Ground Connections
Table 4 below shows where you place a jumper, depending on what microphone
pin is designated GROUND. For example, if GROUND is designated as being pin
7 on a Kenwood microphone, then you would place a jumper on position R7D in the
GROUND section of header HD2.
Radio MIC Pin
MFJ-1272B
Header
Place a jumper on:
1
HD2
GROUND--R1D
2
HD2
GROUND--R2D
3
HD2
GROUND--R3D
4
HD2
GROUND--R4D
5
HD2
GROUND--R5D
6
HD2
GROUND--R6D
7
HD2
GROUND--R7D
8
HD2
GROUND--R8D
Table 4
Most radios have two ground pins on the microphone, GROUND and
MICROPHONE GROUND. Be sure to use the pin designated as ground, not
microphone ground, when making your jumper connections. The use of the
microphone ground could introduce audio hum in the system.
