Only few wires to solder, holes to drill and the portable mic is ready for the test.
Up/Dwn buttons are much better to be used as el-key. The clicking type buttons are faster than the nice rubber ones on the MH31.
There is 5V in the mic to supply the capsule, and two LEDs as emergency light. Later on it turned out it is a pretty useful feature Chinese engineers built in their handy radios. Writing a log, or finding keys on the face of the radio in the dark becomes a bit easier with this led light.
There is a lock switch on the side witch I connected to the PTT. I often use my tuner right at the feed point of the antenna, which can be couple of feet away from my radio. I can reduce the PWR to 0.5W, turn the radio to PSK mode, switch the lock (PTT) on the side of the mic, and walk to the tuner to match the antenna without assistance.
The capsule sounds so good.
There is a big difference between the original MH31 and the modified.
https://soundcloud.com/user820079127/mic-test-short
Not every electret capsule sounds that good. I advise to use those tiny ones removed from mobile hands-free sets, or cheap Chinese radios.
There are two settings on the mic. One is via 1uF with full basses, and the other one is via 47nF only. That is the perfect DX sound. I modified all my microphones like that.
Have fun!
