scope trace question

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surfsup
Posts: 1513
Joined: Mon Nov 29, 2010 12:21 am
Location: Chicagoland

scope trace question

Post by surfsup »

Anyone seen this type of spike before on their pi plates? Messing around with my new scope and i'm thinking this spike shouldn't be there. Please let me know your thoughts as I am travelling for a couple weeks but would love to have some input while on the road. Also any idea why one trace is clean and the other is noisy?

[img:800:479]http://chicagocadcam.com/ChrisHahn/xen10/PIplates.jpg[/img]
fperron_kt88
Posts: 72
Joined: Wed Oct 10, 2007 2:19 pm
Location: Montreal

Re: scope trace question

Post by fperron_kt88 »

Hello surfsup,

Yup, got the same thing a while back. See this thread: http://ampgarage.com/forum/viewtopic.ph ... c&start=15

In the youtube vid, you see the trace in question: http://www.youtube.com/watch?gl=CA&hl=en&v=TRfByCL74rM

Since the blip is on only one polarity of the PI outputs, the trick is to use the other polarity so this part is not contributing any signal in the following class AB stage...

If my memory serves me properly, the signal appearance was related to a change in the bias of the PI under grid conduction.
...
surfsup
Posts: 1513
Joined: Mon Nov 29, 2010 12:21 am
Location: Chicagoland

Re: scope trace question

Post by surfsup »

Awesome dude. Thanks. I'll research your thread this week as i'm in toronto for the canadian manufacturing show.
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