[sdiy] When building a White Noise module has anyone ......

[Rykhaard D.A.M.I.A.N.]

On 1/9/06, harrybissell <harrybissell at prodigy.net> wrote:
>
> One idea...
>
> Power the noise module, alone... from a couple of batteries.
>
> Remove it entierly from the modular, and hook it up with only
> two wires... a ground and a signal.  One shielded cable should
> be sufficient.
>
> If your problems go away... you have power supply or grounding
> issues.
>
> If they don't go away... you have something VERY strange in your
> noise module.


K.  Thanks Harry. :)  I never thought of that.  :)
With the progress that I'd made, after I'd writ the original message, I
don't think that it's too severe. :)  But, I'm still going to try your
suggestion, anyways. :)

You migth try the noise module with only ONE wire... the ground.
>
> You can try your noise module with NO wires.


This was close to how it was, when I first powered up.  It was hooked up
(outside of power) only to the scope, to verify it's operation, or not.  )
1st - 2N3904 (100 times + 100 times amplification) - almost rail to rail
noise on the scope
2nd - 2N2712 (same amplification) - noise on the scope was about 60mV peak
to peak
3rd - different 2N3904 (same as 1st)

As I'd said in my last message - changing the 2nd amp to a pot, helped
greatly. :)

I'm still going to check into extra filtering as well, though.  With the
full amplification and the 2 foot banana cord, just moving the cable away
from any other patch cables, greatly helped reduce the amplitude of the
noise, through the system. :O

(I once showed a manufacturer that I could noise hit their solid
> state relay modules through the air... but totally floating their
> module and making a noise spike nearby.  They had been blaming EVERYONE
> else for the problem for months. After that, they went home quietly
> and fixed their sh!t !!!)
>
> Where can you see the noise on the scope ???
>
> H^) harry


Harry!  You have ALL of the fun in life, with electrical things!  :D :D
Blaming every1 else, for months. :O  hahahahaha. :D  Cool experience. :O :)

The noise on the scope, through all above mentionings, is properly centered
about ground, as well.  No offsets.  It's good looking, anyways. :)

I figured at worst case - if I couldn't get this 'repaired' properly, I
would just keep a lower amplitude version of it running, as a switch on /
off source for the on board Sample & Hold only. :)  Shall see what happens
tomorrow. :)

I came up with a new VCO idea tonight at work.  I'm off to the Design
section of my webpage, to post it at. :)

Thank you both, greatly, for your help and suggestions! :O :O

Funny in a way - I come back to building modular gear, after almost 10 years
- forgetting a lot of stuff - and run in to completely NEW problems. :O
Hahaha.  All part of learning.  And the help is far beyond, appreciated,
from everyone. :O
Someday - I hope to be able to do the same, for others. :)

--
Take care,
Warmth and Peace,
Ryk

http://deathlehem.bravehost.com/damian.html - D.A.M.I.A.N.;s webpage - Jan.
0406 update
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