So what you are saying is that once you take the Laplace transform of an impulse you get 1 divided by what!!!!

Is this a joke ?
The laplace of an impluse function is 1. Or 1/1

I am assuming you mean the delta function

without entering the theory of distributions the integral
is not defined

Anyway what the hell does this have to do with my previous questions?

What happens when you take the derivative of the delta function.
Same question but for the step function heaviside ,.....

Please don't answer this this can be talked about in the math forum haven't had to much time to get into anwsering question their to busy learning electronics....

 

With all respect, I am not able to comprehend your writing. "Masters degree in mathematics" I would of never approve your thesis.....

 

Thats why I had a proof reader (no pun intended) but I have never been good with spelling and I am typing fast to get back to testing things

 

Thats why I had a proof reader (no pun intended) but I have never been good with spelling and I am typing fast to get back to testing things

I understand, let us proceed with your original question!!!

 

You need to do some circuit diagnosis with an oscilloscope. The noise waveform should be easy to pick out with no voice present. Then start subtracting your equipment power until the noise abates. At least you have isolated it, now you can begin to solve the problem.

Regards, DPW [ Spent years making heaters out of op-amps.]

 

You need to do some circuit diagnosis with an oscilloscope. The noise waveform should be easy to pick out with no voice present. Then start subtracting your equipment power until the noise abates. At least you have isolated it, now you can begin to solve the problem.

I think you're asking a bit much from our OP.

He only wanted to know what the noise was, and how to stop it.

But it really doesn't matter what you tell him, as they will read something and then substitute random values instead of what the proper values are.

And then write for pages about how the other-than-correct values don't work, and why don't they work, but they should work (they think) and there should be a better way, but there doesn't seem to be, but why can't I just throw any values into a circuit that I want to and have it work just like I want it to.

It's really odd, and I really don't get why he don't understand it. With a Masters in mathematics, this stuff should be mostly a piece of cake to him.

It's all math, touched with a bit of experience and common sense.

 

deleted double post.

 

Did you use the audio isolation transformer or not???

Did you disconnect the circuit from the red and green telephone line wires to see if your audio cable is picking up hum or not???

I just thought about the audio trandformer picking up magnetic hum from a nearby power supply transformer or CRT TV or monitor. Is there a power supply transformer or CRT near the audio transformer?

 

Did you use the audio isolation transformer or not???

Did you disconnect the circuit from the red and green telephone line wires to see if your audio cable is picking up hum or not???

I just thought about the audio trandformer picking up magnetic hum from a nearby power supply transformer or CRT TV or monitor. Is there a power supply transformer or CRT near the audio transformer?

Well I am using audio isolation transformer ratio 1:1 600ohm to 600ohm
Everything in the circuit digram is the same except the cap value I mention earlier.

When I disconnect the circuit from the green and red wires of the telephone lines and leave the device plugged in I get NO NOISE what so ever when I unmute the line in port.

So it must be either the capacitor wrong value or I CRT / power device around here... I do have many monitors and wires for various computers , ...and other devices but I would think I would here the hum after I disconnected the phone lines and left the device in but connected the transformer 2 connecting wires together (which where the ones connected to the green/red phone lines )

dun maybe their is away to rule out the devices around my recording ciruit in any easier manner then removing them all /disconnecting them all ...which currently would take way to long and is not an option in my current state....

I would think this is more then just the wrong capacitor value....

In theory I would think all I needed is the audio isolationing transformer 600:600 ohm and maybe 2 zeners for protection and maybe a pot for volume control. (but that really isn't nessary the pot sense the computer audio software can control the volume of the line in port...)

Anyway the question still remains I have tried just using the audio transformer with the 2 zener diode and even that has the humming when I connect the green/red telephone lines to it? So the problem seems to me that it is cause by some 60hz harmonic distortion coming from power supply.... remember I did say I had VOIP from comcast and the phone plugs into the RJ11 jack of the cable modem....

But I figured since the cable modems rj11 jack follows the same voltage/current standards as the POTS phone system it would work in both this case...???

Maybe the power supply from the cable modem is giving off interference with the rj11 phone jack.... But I don't hear anything significant in the phone maybe it is just being amplified ....

This is all I can think of to tell you.
Basically any circuit I make has the same noise so how can I some how filter it by using a high pass filter over 60 hz or something?