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[DPRG] Re: Need help debugging a XTAL colpitts oscillator

Subject: [DPRG] Re: Need help debugging a XTAL colpitts oscillator
From: Jeff Koenig koenig.jeff at gmail.com
Date: Wed Jun 23 23:46:38 CDT 2010

Hey Ray -

Haha!  You haven't wasted anyone's time.  Kip's suggestion was a very good
one.  Matter of fact, you didn't even waste much of your own, although it
probably feels like it right now.

You've learned a great lesson that some people take decades to learn, if
ever.  ALWAYS be suspicious of your instruments!  Digital o'scopes, in
particular, are great at aliasing under certain conditions.  They don't
really "lie", but they're only telling you what they see to the best of
their ability.  Get to know Nyquist, aliasing and other o'scope limitations
early on, and you'll do just fine.

Congratulations to you for not giving up!

-Jeff

On Wed, Jun 23, 2010 at 8:28 PM, Ray Xu <rayxu123 at gmail.com> wrote:

> Hey Kip,
>
> Thanks for the info.
>
> I found out that this signal of mine is indeed a "ghost signal".  In a
> short wrap, my scope was aliasing the signal at higher time scales...
>
> So, basically, I've been trying to solve a problem that doesn't exist for
> the past week...Wow, I feel stupid of myself that I got myself into this
> kind of situation...
>
> Sorry for wasting your time
>
> Thanks,
>
> Ray Xu
>
> On Wed, Jun 23, 2010 at 7:47 AM, Kipton Moravec <kip at kdream.com> wrote:
>
>> I think you are on the right path with the decoupling capacitors.
>>
>
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