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Subject: Re: [motm] Scope question

From: David Abbey <abbeysynth@...>
Date: 2009-01-29

Beg, borrow, make or buy yourself a coaxial cable with a BNC connector on at least one end.  Solder a 1/4" phone plug to the other end (tip to center conductor and sleeve to the braid, but be careful not to over heat the braid and melt the dielectric).  You can break out a signal with a multiple by routing your signal into one jack, taking it out of another in that multiple and plugging your 'scope cable into a third.  I made 2 for my 'scope (A and B channels).  I also made one with bananna plugs on one end to use with my DMM.


From: jneilnyc <jneil@...>
To: motm@yahoogroups.com
Sent: Wednesday, January 28, 2009 8:24:37 PM
Subject: [motm] Scope question


I finally sat down tonight at got my Tektronix to give me some
waveform views of one of my oscillators. There was more than a little
trial-and-error at first, but once I got in the ballpark I was able to
zero in on clear, static waveforms that changed shape in predictable
and expected ways, which was immensely satisfying (and will no doubt
impress my musical buddies, for whom a MOTM cabinet is already like
seeing something out of Close Encounters - this now adds that last mad
scientist touch).

And I got the onboard frequency counter working, which is a nice plus.

All this was done using a rather painful method whereby I clipped the
ground to one exposed terminal on the end of a phone cable and touched
the probe to the other. While this worked, it was not at all easy to
do one-handed, and clearly not a long-term methodology. What I really
want is to make this kind of connection permanent, ie just have some
sort of probe terminating in a phone plug that I can tap into any jack
without worrying about fiddly connections. Does such a thing exist,
either ready-to-use or in some combination of probes+adaptors?

What do people who know what they're doing do? (he said, and not for
the first time...)

Thanks!
JN