Parts required:

• Small enclosure to house photo diode e.g. Hammond 1551GBK 50mm X 35mm X 20mm ABS enclosure.
• PH310 photo diode or equivalent - in this case a Panasonic PN323B
• Curly cord or normal cord with a shield and inner conductor, approx 400mm long
• Optional - Material covered neoprene to replace original foam padding.

Step 1:

Remove the elastic head band from the unit. With all our headsets we have also removed the foam cushioning from the back of the headset and replaced it with wider cloth covered neoprene cushioning. This is optional but does make the headsets more comfortable. If you do not want to do this just poke a screwdriver through the foam to undo the screws.

Undo the three screws holding the headset together and pull the back section away from the front.

Step 3:

Remove the screw holding the PCB at one end and remove the piezo speaker from its holders.

Step 4:

Step 5:

Solder cable wires to existing photo diode legs, ensuring correct polarity. The shield of the cable should be connected to the ground leg and the inner conductor should be connected to the positive leg.

Step 6:

Run the cable under the PCB, under the piezo speaker and align the cable with the removed section at the far side of the headset. Reposition the piezo speaker and replace the PCB screw. Check that the headset can be put back together properly and that everything lines up. Replace the three screws at the back of the headset.

Step 7:

For these mods I have used a Hammond plastic enclosure part no 1551GBK. This measures 50mm X 35mm X 20mm. Using a cutting wheel on a dremel type tool a slot is cut into each end of the box to allow the headband elastic to thread through. At one end a hole is drilled to allow for the cable to enter.

Step 8:

Two small holes are drilled through the lid of the enclosure, which the legs of the new photo diode push through. The legs are bent around so that they are flat on the other side. A small amount of super glue is placed on the back (flat side) of the photo diode to hold it in position.

Step 9:

Take the elastic headband and rethread the sewn end onto the headset, pass the headband through the enclosure and out the other side. Rethread the headband at the other end of the headset where the new cable is coming out.  Take the cable from the headset and thread it through the hole in the enclosure. Solder the shield of the cable to the long leg of the photo diode. Solder the inner conductor to the short leg of the photo diode. It is a good idea to use heatshrink or electrical tape to insulate the legs of the photo diode, also adding a cable tie around the cable will prevent pull on the photo diode. Place the lid on the enclosure and do up the screws. Install a battery into the headset and turn the power on to A or B. Check for +5V DC on the legs of the new photo diode, if you have less than this (under 2V), then the polarity of the photo diode is wrong and you will need to swap connections in the enclosure. Check that the new sensor works by firing at it with a gun on the appropriate setting. You should hear that familiar sound of a successful hit.