VS. Yaesu MD100A8X vs. Stock MH-31A There are a lot of ham radio microphone tests on Youtube, but I have often found them lacking, because they do not include over-the-air audio showing what the operator on the other end hears. For this test, I was lucky enough to encounter DV3XUK in the Philippines, and record several minutes from his Yaesu FT-450D, comparing various settings of his new MD100A8X microphone upgrade, to the stock MH-31A (back switch 1 only -- sorry, we forgot setting 2). I recorded the video using my Yaesu FT-950, at a typical DX receive bandwidth of 2400Hz. The distance between my station, in Seoul Korea, and his in the Philippines, was about 1600 miles (2573 km). As he felt with his Yaesu 450D, I believed the stock MD-31 microphone on my FT-950 did a pretty poor job of exploiting the rig’s excellent transmit sound capabilities. Although perfectly adequate for general voice communication, the MH-31 “hand grenade” microphone garners few positive over-the-air comments. If you own a newer Yaesu radio, such as the 450D, FTDX1200, or FTDX3000, you might notice the same, and consider upgrading the MH-31 to Yaesu’s MD100A8X, heard in this test. Per Yaesu specifications, the MD100A8X boasts a cardioid dynamic mic element, at 500 ohms unbalanced. It allows up/down tuning on compatible transceivers, a scan switch, PTT switch, and a lock feature. The bottom of the mic base features High Emphasis and Low Cut switches. Connections are made by a nifty reversible cable, which terminates to an 8-pin mic plug on one end, and a modular plug on the other. This cable allows you to simply flip the cable around to match your model of Yaesu radio (with the exception of some older models, like the FT-757GXII and 736R), with the other end of the plug fitting the proper choice of input on the back of the mic. Frequency response of the MD100 A8X ranges from 100 to 5000 Hz, with a sensitivity of -75db (0 db=1 V/0.1 Pascal). It tips the scales at 24 ounces (670 grams).