MFJ Telepatch II, Instruction Manual

a.  Determine which pins of the micrphone connector (either modular or round) are used 

for the Mic Audio and the Mic Ground. The wiring for most radio microphones will 
be printed in the radio instruction manual. Write the pin numbers in the following 
table for reference. Note, some radios have two ground connections on the 
microphone. The ground used for PTT ground should be the one used 

Description 

Radio Pin Number 

Mic Audio 

Mic Ground 

 
b. Jumper 

Configuration 

The MFJ-624DM must be configured specifically for the transceiver being 
connected.  The MFJ-624DM comes from the MFJ Factory pre-configured to 
operate with the ICOM 706 Series.

a.  Remove the cover of the MFJ-624DM by loosening the six screws on each 

side of the cover.  Be careful not to misplace them.  Remove the cover from 
the chassis and locate the headers on the right side of the board labeled JMP 1 
(MIC GND), JMP2 (MIC AUDIO), JMP3 (THRU PASS), JMP4 (MIC 
AUDIO).   

b.  Remove each of the jumpers on each of the headers. A small pair of needle 

nose pliers will make this much easier. 

c.  Using the Pin numbers previously written in the table above and re-place 

jumpers in the following order. 

i.  JMP4 (Mic Audio),  place a single jumper on the number 

corosponding to the radio pin number previously recorded above.  
Note: Only one jumper should be placed on JMP4 (Mic Audio) 

ii.  JMP2 (Mic Audio), place a single jumper on the number corosponding 

to the radio pin number previously recorded above. This will be the 
same as in step I above.  Note: Only one jumper should be placed on 
JMP2 (Mic Audio). 

iii.  

1.  JMP1 (Mic Gnd), place a single jumper on the number 

corresponding to the radio pin number recorded above for 
Radio Microphone Ground. Note: Only one jumper should be 
placed on JMP4 (Mic Audio). 

iv.  JMP3(Thru Pass) and JMP , place jumpers on the  remaining 7 pins 

not used on any pins of JMP4, JMP2, JMP1.  These jumpers will allow 
the microphone to operate the radio just as it would if plugged directly 
into the radio. 

c.  Connect a shielded audio cable from the headphones, speaker out, or monitor out jack 

of the radio to the AUDIO IN jack on the Telepatch II. 

i. 

If your radio has an 8-pin modular connector use a CAT 5 ethernet computer 
networking cable, such as the MFJ-5397MX, to connect the mic output jack on 
the MFJ-624DM and the mic input jack on the radio.  If your radio has an 8-pin 
round connector a cable such as the MFJ-5398 should be used. 

ii. 

Connect the microphne suppied with your radio to either the 8-pin modular or 8-
pin round mic input jack of the Telepatch II.  Only one microphone should be 
connected to the MFJ-624DM.