Brag: Scope probes

From: Tothwolf <tothwolf_at_concentric.net>
Date: Sat Dec 21 23:09:00 2002

On Fri, 20 Dec 2002, Gunther Schadow wrote:
> Tothwolf wrote:
>
> > I *finally* managed to get probes for my Tektronix 2213 scopes late
> > this last week. I still can't quite decide which project to tackle
> > first ;P
>
> Hehe, you must have very special probe connectors. Here's what I did as
> the cheapie that I am: I took an old Ethernet BNC cable, cut it in half
> and behold I had two scope probes :-). As an added value that I still
> haven't gotten around doing, I will add some cable-shoes at the end.
> Works for my purposes.

The connectors are not special at all, as they are just plain old BNCs.
What I did need were probes that would function correctly at 40-60MHz.

Supposedly, the Tektronix 2213 scopes have an unusual input capacitance
requirement (14 pF), and finding probes that match is a real pain. All of
the 3rd party probe manufacturers that I contacted told me that did not
have a probe that would work properly with the 2213. There are some very
high bandwidth probes made by Tektronix that have an input capacitance of
14pF, but they are *very* expensive (>$100-150ea). I certainly couldn't
justify $200-300 for a pair of probes for each of my 3 2213 scopes,
especially since the scopes only cost me ~$150ea. Back when I bought the
2213 scopes, I actually had a chance to get a 4th, and now sometimes find
myself wishing I had. I ended up buying 14 of the 6120 probes, and nearly
got a couple more. Needless to say, I feel like I got the probes at a very
good price.

The P6120 probes proved to be very difficult to find. I still need to find
the ground leads and slip-on clips, but just finding the probes appears to
be a major accomplishment. For some purposes, I can use a ground lead with
a clip and banana plug connected directly to the scopes, but for the
majority of the plans I have for the scopes, ground leads for the probes
will be important.

Sadly, even though all 3 scopes checked out ok before I stored them, they
all seem to have developed problems over the last year or so. One seemed
to power up ok, but blew its fuse after it warmed up for about 10-15
minutes. Another won't display the 2nd trace in the most common modes. The
3rd doesn't seem to power up. I guess I've got more work ahead of me.
Sigh.

-Toth
Received on Sat Dec 21 2002 - 23:09:00 GMT