Highfields Amateur Radio Club
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Make an MJ-88 Microphone Adapter.
By Brian, MW0GKX.

I've labelled this project as moderate (orange) because it uses a modular plug, therefore requiring the use of specialised crimping pliers, otherwise it would have been easy (green).

This adapter allows the use of 8 Pin round Kenwood microphones on many Kenwood radios with the 8P8C modular socket. The image below shows the view of the 8P8C plug with the locking tab underneath and wire connectors toward you. The 8 Pin round "socket" (actually the male, or plug but referred to as socket) is viewed looking into it as if you were about to put a plug in it. 8 pin Line plug

Parts

8P8C modular plug.
8 pin round line plug (locking ring type, see picture right)
8 core cable to suit.

Method

1 Strip off a small amount of the outer sheath of the cable and, making a note of the order of the colours, crimp the modular plug onto the cable.
2 Cut the cable to the required length (if not already).
3 Slide the line socket body onto the cable.
4 Strip some of the sheath from the free end of the cables and strip and tin the free ends wires ready to connect the line socket.
5 Using the notes made in step 1 and referring to the table below, solder the wires to the correct pins on the line socket.
6 Assemble the line socket once connections have been checked and whiskers have been removed.

8 pin Modular PlugPinSignalPin8 pin Round Plug (socket)
modular plug1Frequency Down3round plug
2No Connection
(Audio out on some models)
N/C
(or 6)
3Mic Audio1
4Mic Ground7
5PTT2
6Ground
(PTT and other functions)
8
7+8v5
8Frequency Up4

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