Electret Microphone Circuit For Ham Radio

The adapter circuit shall employ a 10 db 2 resistor l network attenuator pad voltage divider to attenuate electret condenser microphone s open signal voltage.

Electret microphone circuit for ham radio.

When it comes to punchy audio on ssb the yaesu ft 817 is notoriously weak. Electret microphones 101 duration. 2 the test circuit for an electret microphone the electret microphone jfet amplifier has the gate connected to a pick up plate which is pushed back and forth by the air the source is connected to the ground and the drain is connected to the output pin. Take the audio off of the resistor mic junction thru a cap into an audio amp and see if it works.

Ham radio basics jim w6lg shows the dipole antenna and an instantaneous antenna tuner duration. Yeah it worked ok with my rig. Ecm elements can have very wide frequency response from 10hz up to 30 000hz depending on the ecm style you get. There are many solutions to this problem from replacing the dynamic microphone capsule with an electret mic to hf clipper circuits.

However the hmm ic did not outperform what a typical electret mic element offers at a price of about 1 at your local electronic parts. I actually tried the electret mic mod but with no luck the audio sounded terrible even though i tried different electret capsules. The simple audio chain for the kenwood starts with the cheap electret microphone project that runs into my station pc soundcard with the audio processed by the voice shaper program which is then run from the soundcard output through an old jbl 7110 compressor limiter and then into the balanced line input of the kenwood. Ham radios do not enjoy the wide frequency response of recording and broadcast studios.

I had a need for an electret mic so as to be compatible with my icom 765. But the frequency response and gain factors of the ecm mics are becoming a high quality low cost alternative to great audio reports on ham radios. If it is an electret doesn t look like a typical one try feeding the red wire from about 3v thru a 2 2k resistor. The adapter circuit shall include three 3 5 mm phone jacks for connecting the microphone headphone and ptt switch respectively.

I bought the hmm ic for about 60 at the local ham store brought it home and installed it on my rig. When using a dynamic element on rigs like icoms which were designed for electret microphone elements one must not be afraid to do two things. Dsp and mic gain settings. If it is a dynamic you should get audio with no voltage input.