I’m often amazed by the sound quality of HAM radio stations. I regularly make Ragchew QSOs and call CQ on the bands. But what surprises me most is that most amateur radio operators these days have no clue what their audio sounds like, what their transmit bandwidth (TBW) is, or whether they’re using any Audio processing (PROC) at all. This leads to all sorts of problems, such as distorted audio, poor audio quality, and worse, splatter on adjacent frequencies. More information about splatter and a clean signal can be found in the article “How Clean is your signal …?”.
Within the amateur radio industry, manufacturers (OEMs) such as Yaesu, Icom, Kenwood, etc. use the terms “processing” or “compression.” Both processes are intended to improve audio quality, so receiving stations can hear a better and clearer sound(audio). Even OEMs are implementing transmit(receive) equalizers (TX EQ) in their radios, allowing users to customize their audio to their own preferences. Therfore setting up good audio quality isn’t rocket science, but it shouldn’t be taken lightly either.
Several aspects play a role in setting up your audio. You should always consider the type of microphone you want to use. For example, the standard microphone that comes with your radio, or do you want a more advanced, professional studio microphone? When choosing your microphone, you also need to consider various technical aspects, such as: do I want a condenser or a dynamic microphone? Do I know the microphone’s frequency response, and is it compatible with the radio I want to use?
After you’ve chosen your microphone and know which radio you want to use, you need to figure out how to get the most out of your audio. This means testing the audio quality by monitoring yourself with your radio’s MONI function, or find a WEBSDR nearby (make sure you use a clear frequency where you won’t disturb anyone), or ask a trusted friend to help you during a QSO. Also adjust your microphone’s gain and TBW, in conjunction with your processor or compressor (some manufacturers, such as Icom, use a compressor). Reading the manual, especially if you’re inexperienced, will guide you how to adjust your microphone and processor’s gain levels. An incorrect audio setting will not only make your audio sound bad or cause distortion, but can also overload the ALC (Automatic Level Control, a feedback circuit designed to prevent the transceiver’s power amplifier from overloading, ensuring a clean, undistorted signal).
In summary, a HAM radio amateur should always know how their audio sounds and, more importantly, what all the parameter settings are when broadcasting into the airwaves
For additional support, you can use the simple but effective guides below.
- Check your current Transmit Band Width (TBW)
- Check if your MIC. gain is set up properly
- Check if I am not overdriving my PROC. (COMP) causing the ALC to clip
- Before making my first transmission I will monitor myself by using the MONI. gain to listen to my audio
*By clicking on the Blue Key words you will be re-routed to YouTube explanatory videos on how to set up proper the above mentioned topics.
If you would like to know more about this topic please do not hestitate to drop me an email at roma-dx@ziggo.nl or just use the CONTACT form on this webpage.
73 Roberto PB5X
