Re: Tek 547 A Sweep display during retrace


Dave Wise
 

I hope someone can try it out. I'm out of town right now.

Dave Wise

On Nov 9, 2017, at 2:05 PM, David davidwhess@gmail.com<mailto:davidwhess@gmail.com> [TekScopes] <TekScopes@yahoogroups.com<mailto:TekScopes@yahoogroups.com>> wrote:

The 2N5401 might still be fast enough. I suggested it and the BC556
because they are relatively common. The KSA992 is the best of the
commonly available and inexpensive options that I found.

I was not able to find any detailed specifications on the original
2N2207 to make a better comparison between it and modern parts. The
low voltage output capacitance is a start but not sufficient.

On Thu, 9 Nov 2017 19:48:38 +0000, you wrote:

I think KSA992 is a better bet with 3pf max.

Dave Wise

On Nov 9, 2017, at 11:15 AM, David Wise david_wise@phoenix.com<mailto:david_wise@phoenix.com><mailto:david_wise@phoenix.com> [TekScopes] <TekScopes@yahoogroups.com<mailto:TekScopes@yahoogroups.com><mailto:TekScopes@yahoogroups.com>> wrote:

2N5401 is 6pf vs 2.3 . It will be much slower in this application.


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Posted by: David <davidwhess@gmail.com<mailto:davidwhess@gmail.com>>
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