How to Modify A CM108 Sound Fob For Allstar.

Simple Allstar node.

Modify a CM108 sound fob for use with Allstar. Using regular sized components

Please note that this is now one of my older designs.

My latest version can be seen HERE

CM108 Allstar
An unmodified CM108 sound fob. These are very cheap to buy.

This page covers how to modify a CM108 sound fob for use in an Allstar node. Be sure to read the previous section on how to attach the fine PTT and COS wites to the CM108 sound fob. before you begin.

I also have a newer design with surface mount resistors instead of the conventional ones shown, You can  check this out via this link: LINK

modify CM108
My rough schematic. Click to enlarge.
CM108 Allstar
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Step 1: Remove the green and pink sockets, this is best done with a heat gun. Try not to apply force or you may damage the solder pads, best just apply heat and let then just float off.
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Step 2. Remove resistors R6 and R7 and also capacitor C2. Then cut the tracks in the three place shown.
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Step3. Add your 2N3904 transistor.
CM108 Allstar
Step 4: Add a 10K resistor.
Step 4. Add a 10K resistor in the position shown.
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Step 5. Add the fine PTT wire.
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Step 6. Add the fine COS wire.
CM108 Allstar
Click to enlarge.
Step 7. Add a 1K resistor at the bottom and a 10K resistor at the top.
Step 8: Finally just add the four wires to hook it up to your radio.
Step 8. Finally, just Add the four wires to hook the sound fob up to your radio.

The above photo shows a completed sound fob which is ready to insert into a node, and this may be enough for your needs particularly if you use the excellent Node Remote app to control the node.

However, if you visit my More section you will find instructions on how to further modify the fob to include indicator lights for the front panel. This is simple matter and no coding is required. : LINK