I think I might have posted something similar before. Think ready made mic pre-amp compressor

[Onelasttime]

MAX4466 Electret Microphone Preamplifier Board SSM2167 Voice Compression DC3V-5V

 

[Onelasttime]

They are under $5 each on the ebay. I have not used them but we are all familar with this family of parts in past products that where fairly expensive in the past. Add a voltage regulator if the radio you are installing it in does not 3V-5V internaly and you have a lot of performance for cheap!

 

[Cable Guy]

SSM2167 Microphone Preamp Board Preamp COMP Compression Module DC 3V~5V | eBay

This preamplifier includes a built-in compression and noise gate. For this function, it is better than using an op amp in the preamplifier circuit. The noise gate attenuates the signal level below a certain threshold,in order to amplify only the desired signal, such as speech, and reduce the...

ebay.us

I got a couple of these and they were legit, only they don't play well with other add-ons like an echo board. If mounting inside a high powered radio, good shielding is a must. The version I got uses the same ssm2167 chip. IIRC, there is another revision of that chip that incorporates EQ although the number escapes me. These are fun.

 

[Cable Guy]

SSM2167 – uBitx

Above link has some good info to consider if trying to implement these things, especially into a radio, and taming the output with a 10k pot will prevent it from overdriving the radio. I bought a handful to experiment with and blew a few up in the process. Also, they say 3-5vdc but I found better stability right at 3v. Ymmv.