The Tuner +3 is a fine microphone for communications. Besides being amplified, it has an audio compressor inside that makes for louder average modulation without over-modulating your radio. This microphone was briefly made in the early 1970s. Problem today is the microphone is old with failing electrolytic & tantalum capacitors inside. The original ceramic capacitors are good- they never fail. Rebuilding the microphone to sound better than new only requires a few select parts. These are parts known for audio quality & sound better than ordinary parts. The parts are: 2x 22uF @ 16 volt Elna Silmic II capacitors (replaces 20uF & 15uF) 2x 4.7uF @ 25 volt Elna Silmic II capacitors (replaces 5uF) 1x 2.2uF MKC 1862 poly type capacitor (replaces 5uF from volume control wiper to white wire audio output) 2x .47uF Panasonic Poly type capacitors (replaces tiny blue tantalum capacitors. The poly type capacitors are larger, but will fit. Move the transistor slightly (bend over) and place the MKC 1862 capacitor on its side. The Elna Silmic are very fine audio grade capacitors and the poly types are great for audio. The original Tantalum are terrible sounding caps. Remember proper polarity with the new Silmic II capacitors. The poly types have no polarity, cannot install backwards. The schematic is on the internet. Your microphone will sound more clear than ever with the new parts plus get back those nice high frequencies with the deep & powerful bass.