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PC HEADSET INTERFACE

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This is a simple interface that will let you use your pc-multimedia headset on your ham rig.

It’s a small plastic box with two sockets for the headset jacks.

On the top side there are a pushbutton and a switch: they are both used to activate the transmission (PTT).

There is a reason why I’ve used two devices to activate the same function: the pushbutton can be used for short transmissions,while the switch can be used for longer ones,or when an “hands free” operation is required.

I’ve also used a red LED,that will turn on only if the PTT is activated from the switch,to prevent unwanted transmissions.

There is one more way to activate the PTT:a foot switch input,useful for the real hands free operation.

All the signals going to the radio are terminated on a 8 pin DIN socket.

With this solution the same interface can be used on several radios: one cable can be made for each radio,each one with the proper plugs and connections on the radio side,and using an 8 pin DIN plug on the other side,the interface can be swapped from one rig to another.

The power supply for the LED and for the electret mic can be taken from the +V pin available at the mic socket of the radio

The resistor and the polarized capacitor are respectively used to reduce the supply voltage to the mic at 2V,and to decouple the microphone DC supply from the AF signal sent to the mic input on the radio.

The VK200 chockes are required to avoid RFI.

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DISCLAIMER

On most of the modern transceivers the transmission is activated by grounding (GND) the PTT pin (on the mic socket).

Some rigs may not work that way: therefore check the manual of your rig first,and modify the circuit if needed.

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I’m using this interface on my VHF/UHF radio.

For local QSO’s on the 2m band I personally find the headset a bit bulky,so I’ve used another type of pc-multimedia mic,the model with a sticky base and the swiveling support.

I’ve installed it in a position where it can be easily pulled away when not in use,and it comes with the same jack and the same connections of the mic on the headset,it’s 100% compatible.

Used with the foot switch,I can ragchew on the 2m or 70cm bands totally “hands free”.

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