Re: Puzzle of the day: 465b will not trigger on channel 2 SUCCESS!


 

The 2N3906 transistors will be too slow and have too much input
capacitance which may affect the bandwidth and transient response but
you may not even notice without a good test signal.

On Sat, 18 May 2013 04:51:19 -0000, "jeffbathwater1"
<jeffbathwater@gmail.com> wrote:

You are a genius!
I just happen to have a 2N3906 in my junk box... I now have two rock steady traces! Thank You!
I will track down the proper replacement but for now it looks like this will get me going.

What a neat group!

Dave

--- In TekScopes@yahoogroups.com, David <davidwhess@...> wrote:

I looked the transistors up earlier. Q1746 and Q1954 have an Ft of
900 MHz, Ccb of 3 pf, and are similar to a 2N4258 or PN4258.

Any PNP RF transistor like an MPSH81 should work but you can use
2N3906 transistors temporarily. Matching is not needed because
adjusting R1835 will trim out any offset.

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