Sending square signal to DRA818 mic input

Hello All,

I am writing a program to send morse information to UHF band.
My arduino produce a square signal morse that i want to input in mic in entry of the DRA818.

The signal produce in the air is not really understandable. Because of the square signal and not a wave signal approching 800hz sin wave.

Any help to send my square morse to mic in will be appreciate? Need i a filter ? a little board adaptation ?
I have a pcf8591 a/d board but i think it not appropriate to use it.

Thx.
SebFox

Hello

You need a pot to limit the input voltage.

How do you control PTT?

Hello

Arduino is contoling PTT and it's working fine, DRA818 pass to emit when i control it.
I have put a voltage divider *2 and liaison capacitor before accsssing to mic in but it sound very loud and bot like morse

It appears you are drastically over driving the microphone input. A microphone or “mic” level is in the region of 0.001 volts (1 millivolt) to 0.01 volts (10 millivolts) . This voltage range may also be expressed as -60 dBV to -40 dBV. You need to increase by a lot your attenuation. The garbage you are hearing is clipping. If you have a scope check it out.

@gilshultz thx for your answer, i have a 50mv square now on the mic in DRA818 and same result

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