Improving communication readability.

[alan_k]

In my experience with handheld radios the microphone gain is set too high. A lot are designed to be held 5-10 centimetres away from the mouth so when using a close miked headset the audio is too loud.

In a quiet environment you could whisper but with the motor running this doesn’t work because the motor noise drowns out the speech. If you try talking loudly into the microphone the audio is then distorted plus the background engine noise.

The solution is to reduce the gain of the microphone circuit. On a 2 metre radio I reduced it by a factor of 30 and with a PMR446 radio by a factor of 10. The audio from the headset mic is now much clearer with well reduced background noise.

If you can’t do this modification yourself find a friendly radio ham or a mate who can. To make thing easier it is worthwhile searching for the circuit diagram of the radio on the web. Google ‘IcomXYZ circuit diagram’ with your radio model number, with some searching you can usually find a free copy somewhere.

Cheers,

Alan