14 Dec
2002
14 Dec
'02
10:53 p.m.
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
Unfortunately, most of the P6120 probes are missing the slip-on clip and
ground leads, so I appear to have some more searching ahead of me. Only
one probe has a ground lead, which has obviously been damaged and repaired
by a previous owner. I suspect and hope that the ground leads and clips
will be easier to find than the rest of the probe. Does anyone know
offhand of a source for these parts? I don't expect Tektronix to have the
parts still available, since they told me that they sold off all parts and
spares for the 2213 series to GTE. The last time I talked to someone at
GTE about 2213 parts, they were less than helpful, and suggested I either
send them the scope for repairs (it just needs the plastic front panel) or
go buy a new scope.
-Toth
20 Dec
20 Dec
10:31 a.m.
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.
-Gunther
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
Unfortunately, most of the P6120 probes are missing the slip-on clip and
ground leads, so I appear to have some more searching ahead of me. Only
one probe has a ground lead, which has obviously been damaged and repaired
by a previous owner. I suspect and hope that the ground leads and clips
will be easier to find than the rest of the probe. Does anyone know
offhand of a source for these parts? I don't expect Tektronix to have the
parts still available, since they told me that they sold off all parts and
spares for the 2213 series to GTE. The last time I talked to someone at
GTE about 2213 parts, they were less than helpful, and suggested I either
send them the scope for repairs (it just needs the plastic front panel) or
go buy a new scope.
-Toth
10:56 a.m.
On Fri, 20 Dec 2002, Gunther Schadow wrote:
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.
-Gunther
Add a 453 Ohm non-inductive series resistor on the end of the cable (and a 50
Ohm terminator on the scope end if you do not have 50 Ohm inputs) and you will
have a 10/1 probe with 500 Ohm input impedance and at least a couple hundred
MHz bandwidth...
If the 500 Ohm impedance bothers you just remember that a standard 20 pF input
impedance scope probe has about the same capacitive reactance at 16 MHz...
Tothwolf wrote:
Peter Wallace
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
Unfortunately, most of the P6120 probes are missing the slip-on clip and
ground leads, so I appear to have some more searching ahead of me. Only
one probe has a ground lead, which has obviously been damaged and repaired
by a previous owner. I suspect and hope that the ground leads and clips
will be easier to find than the rest of the probe. Does anyone know
offhand of a source for these parts? I don't expect Tektronix to have the
parts still available, since they told me that they sold off all parts and
spares for the 2213 series to GTE. The last time I talked to someone at
GTE about 2213 parts, they were less than helpful, and suggested I either
send them the scope for repairs (it just needs the plastic front panel) or
go buy a new scope.
-Toth
12:52 p.m.
Gunther Schadow wrote:
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.
-Gunther
Well, for x1 that's okay, but real scope probes are x10, with
compensation for higher frequencies. Best to use a properly designed
probe with those neat little tips and nonsense. Makes life really nice.
Gary Hildebrand
St. Joseph, MO
1:14 p.m.
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6:11 p.m.
Tothwolf wrote:
Unfortunately, most of the P6120 probes are missing the
slip-on clip and
ground leads, so I appear to have some more searching ahead of me. Only
one probe has a ground lead, which has obviously been damaged and repaired
by a previous owner. I suspect and hope that the ground leads and clips
will be easier to find than the rest of the probe. Does anyone know
offhand of a source for these parts? I don't expect Tektronix to have the
Why not just connect a test lead with banana plug at the 'scope end,
an an alligator clip on the other end, to the ground connector on the
'scope and use that? Works for me. I've always found the ground
leads attached to probes of 'scopes to be too short and useless
anyway... not really worth bothering with. Alternately, can't you
just solder a wire, with an alligator clip on the other end, to the
'scope's probe? None of my 'scope probes have ground wires, other
than the cable shielding, connected to them, and this has resulted in
no problems during the past couple of decades.
Is there something that I'm overlooking?
--
Copyright (C) 2002 R. D. Davis The difference between humans & other animals:
All Rights Reserved an unnatural belief that we're above Nature &
rdd(a)rddavis.org 410-744-4900 her other creatures, using dogma to justify such
http://www.rddavis.org beliefs and to justify much human cruelty.
21 Dec
21 Dec
12:15 a.m.
----- Original Message -----
From: "R. D. Davis" <rdd(a)rddavis.org>
Why not just connect a test lead with banana plug at
the 'scope end,
an an alligator clip on the other end, to the ground connector on the
'scope and use that? Works for me. I've always found the ground
leads attached to probes of 'scopes to be too short and useless
anyway... not really worth bothering with. Alternately, can't you
just solder a wire, with an alligator clip on the other end, to the
'scope's probe? None of my 'scope probes have ground wires, other
than the cable shielding, connected to them, and this has resulted in
no problems during the past couple of decades.
Is there something that I'm overlooking?
Surely is--
It's called lead inductance, and when you look at waveforms containing
frequencies above just a few MHz, using that long earth lead instead of the
correct short probe one, what you see on the scope will be way off what
things really look like! The difference will get worse at higher
frequencies.
Dave B
Christchurch, NZ
8:18 a.m.
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22 Dec
22 Dec
6:26 a.m.
Tony wrote:
As I keep on telling people, the most complex
components in a (digital)
circuit are the connecting wires....
Indeed. The hardest thing to convince some digital designers is that
digital circuits AREN'T.
Especially when they are trying to examine signals with fast edges on a
100 MHz scope, and think the edges look just fine. A 100 MHz scope is
*usually* adequate for working with 74LS and 74HC logic, but with modern
CMOS it usually isn't.
We *try* to make digital circuits behave digitally, but a whole host of
things conspire against us.
8:49 a.m.
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21 Dec
21 Dec
6:09 p.m.
On Fri, 20 Dec 2002, Gunther Schadow wrote:
Tothwolf wrote:
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
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.
7884
days inactive
7891
days old
10 comments
8 participants
participants (8)
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ard＠p850ug1.demon.co.uk -
eric＠brouhaha.com -
ghldbrd＠ccp.com -
gunther＠aurora.regenstrief.org -
pcw＠mesanet.com -
rdd＠rddavis.org -
tothwolf＠concentric.net -
tractorb＠ihug.co.nz