Hi there,
I wonder if someone could help me here, I have built one of these microphones and it works well, we are very pleased with it. But I come to build a second one, and there is virtually no sound coming from it at all. If you ramp up the gain and shout into it, there is a very small signal showing, so it is not nothing, however if you switch one of the settings on it, it pops a full signal through.
The mic calibrated really nicely using a function generator and oscilloscope when building it, so I am hoping that the main circuits are fine, and without leading people on the wrong path, I am assuming maybe that I have the transformer the wrong way round, as it seems logical to me that a 1:10 transformer, the wrong way round would give a x20 attenuation, i.e. losing the x10 as if it wasn't there, and then reducing again by x10 for being the wrong way round.
I have tried to test it using the logic of one of the windings giving a low resistance and the other windings giving a much greater resistance, which is the case:
One set of windings = 33 Ω
other windings = 1.36 KΩ
but then I am assuming that that there should be infinite resistance between the windings, however I am getting something similar to 4MΩ which seems a little low.
I am completely new to this, and don't really know how to troubleshoot this at all, could someone give me a few pointers. I am used to troubleshooting things that have already been built correctly.
Please point me in some direction.
Kind regards
Rob
I wonder if someone could help me here, I have built one of these microphones and it works well, we are very pleased with it. But I come to build a second one, and there is virtually no sound coming from it at all. If you ramp up the gain and shout into it, there is a very small signal showing, so it is not nothing, however if you switch one of the settings on it, it pops a full signal through.
The mic calibrated really nicely using a function generator and oscilloscope when building it, so I am hoping that the main circuits are fine, and without leading people on the wrong path, I am assuming maybe that I have the transformer the wrong way round, as it seems logical to me that a 1:10 transformer, the wrong way round would give a x20 attenuation, i.e. losing the x10 as if it wasn't there, and then reducing again by x10 for being the wrong way round.
I have tried to test it using the logic of one of the windings giving a low resistance and the other windings giving a much greater resistance, which is the case:
One set of windings = 33 Ω
other windings = 1.36 KΩ
but then I am assuming that that there should be infinite resistance between the windings, however I am getting something similar to 4MΩ which seems a little low.
I am completely new to this, and don't really know how to troubleshoot this at all, could someone give me a few pointers. I am used to troubleshooting things that have already been built correctly.
Please point me in some direction.
Kind regards
Rob