Yaesu MH-48 Microphone Modification
Below is my attempt at a simple microphone modification by AG0N. The idea is to put a capacitor in parallel with the microphone leads, cutting the highs. Got some good info from N0EQ before starting as well.
Here's the mic. 3 screws and it all comes apart. There's the .01uf 50v capacitor and the IC socket for size comparison.
Once you open the mic, the cord is easily removed. The PTT will also fall out at this point. Now you have just the front half of the mic to work with.
Now you can see the leads going to the mic, red and green. Easy to tell which ones go to the PTT and which ones go to the mic here.
I clipped the wires closer to the board, further from the mic. My plan was to add the IC socket in the middle. My reason? I'm about the world's worst solderer. If I'm not the worst, I'm on the bottom 10 list. I didn't want to work on the board for fear of melting the nearby surface mounted components.
Stripped just a small amount off the wires at each of the 4 ends, then twisted them back together and applied a little acid/flux then solder.
Here's the IC socket. I flattened the pins out so they wouldn't be stabbing into anything inside the mic.
Here I've placed some white 3mil adhesive-backed vinyl over the board, so I don't drip solder or mess up the board in any way. I then soldered the IC socket to the wires
I clipped the leads on the capacitor just a bit, then plugged it into the IC socket- positive to red and negative to black of course. Bent it over so it lays flat.
Covered the area under the mod with some adhesive vinyl again; 3mil, acid-free permanent adhesive.
Also covered the PTT switch, as it had a screw that looked like a possible short-to-ground (see previous pic).
And the finished product. Closed it all up, tested it on the air with some help from Craig, N0EQ who had done a previous recording on this mic's audio, then did another one with the modification. I think it does sound just a little better, so I'm calling the mod a success!