Microphone Amplifier
22.09.2017, 13:39
Hi All,
I've cruised the forum a few times but just joined because I have a problem that's whipping my butt. I have a Turner +2 desktop radio power microphone that I really like, so I thought I'd reproduce the circuit in a mobile mic. The circuit is based on a darlington 2N5306, of which I used an NTE172A(NTE equivalent). I copied the schematic I found online(which matches the mic circuit), and it works but the potentiometer doesn't adjust the output. I've been checking it with an amplifier and an oscilloscope, the Turner works as advertised but the circuit I built seems to be at full output regardless of the pot setting. I've tried another transistor, another pot, another element, the 5 electrolytic microfarad capacitor, but no joy.
Any advice I would greatly appreciate.
I didn't find the right solution from the internet.
References:
https://forum.allaboutcircuits.com/threads/microphone-amplifier.92707/
I've cruised the forum a few times but just joined because I have a problem that's whipping my butt. I have a Turner +2 desktop radio power microphone that I really like, so I thought I'd reproduce the circuit in a mobile mic. The circuit is based on a darlington 2N5306, of which I used an NTE172A(NTE equivalent). I copied the schematic I found online(which matches the mic circuit), and it works but the potentiometer doesn't adjust the output. I've been checking it with an amplifier and an oscilloscope, the Turner works as advertised but the circuit I built seems to be at full output regardless of the pot setting. I've tried another transistor, another pot, another element, the 5 electrolytic microfarad capacitor, but no joy.
Any advice I would greatly appreciate.
I didn't find the right solution from the internet.
References:
https://forum.allaboutcircuits.com/threads/microphone-amplifier.92707/