I bought the hmm ic for about 60 at the local ham store brought it home and installed it on my rig.
Electret microphone circuit for ham radio.
1 utilize the full range of mic gain available and 2 turn on the compression using the compression level control as a secondary mic gain control if necessary.
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.
The adapter circuit shall include three 3 5 mm phone jacks for connecting the microphone headphone and ptt switch respectively.
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.
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.
Yeah it worked ok with my rig.
Tom k8erv montrose colo.
Ham radio basics jim w6lg shows the dipole antenna and an instantaneous antenna tuner duration.
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.
Take the audio off of the resistor mic junction thru a cap into an audio amp and see if it works.
Electret microphones 101 duration.
Ham radios do not enjoy the wide frequency response of recording and broadcast studios.
Dsp and mic gain settings.
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.
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.
When it comes to punchy audio on ssb the yaesu ft 817 is notoriously weak.
I actually tried the electret mic mod but with no luck the audio sounded terrible even though i tried different electret capsules.
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.
The electret microphone test circuit schematic is shown below.
There are many solutions to this problem from replacing the dynamic microphone capsule with an electret mic to hf clipper circuits.
