Date: Wed Feb 21 13:02:42 2007

Author: Bill Norwood

Subject: Re: Banana Plug Leads

Post:
No, No, Guys - you are missing the main point - which is that if you stick
around long enough for your wires to rot there might just be a message to
it. Frankly I try to distance myself as much as possible from the concept of
"Technician Rot."

Bill Norwood
Technician
Physics Elementary Labs
U of MD, College Park
Since 1970

-----Original Message-----
From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On
Behalf Of Michael A Thomason
Sent: Wednesday, February 21, 2007 12:15 PM
To: tap-l@lists.ncsu.edu
Subject: Re: [tap-l] Banana Plug Leads

"The long term failure mode is generally the nylon cover ages, gets brittle
and cracks causing the cover to slip off the metal tip."

NOT! The long term failure mode is someone short circuits the leads and the
plastic around the banana connectors melts!

Michael Thomason
Director of Physics Learning Laboratories
University of Colorado Boulder Department of Physics
303-492-7117
thomason@colorado.edu
http://physicslearning.colorado.edu


-----Original Message-----
From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On
Behalf Of Dan Beeker
Sent: Wednesday, February 21, 2007 7:37 AM
To: tap-l@lists.ncsu.edu
Subject: Re: [tap-l] Banana Plug Leads

Most of the department buys Pomona but make my own up. Our tips are
purchased through Newark though they can be had from other suppliers. They
are made by (E.F.?) Johnson. Colors are somewhat limited unless you by
thousands. Cable is standard test lead wire. The tips cost about $1.00 each
now so little money is saved but it is made up by the convenience of having
the length needed. It seems like I used to get a little metal block when I
ordered them but can't recall getting any recently. I do have several in my
tool box along with the "punch" if anyone needs one. Occasionally we have
faculty complain about how poorly they are assembled. But when I look at the
ones they complain about they usually have a patina that suggests they
predate the modern age. Assembled properly, the push on kind will work
practically forever. If you use a hammer and beat the plastic cover on they
will fail quickly. I have found using just enough pressure to seat the
plastic cover on the metal part ensures longevity. The long term failure
mode is generally the nylon cover ages, gets brittle and cracks causing the
cover to slip off the metal tip. I figure it takes between thirty and fifty
years for that to happen.

Dan Beeker
Undergraduate Physics Lab Coordinator

Swain West 115
Physics Department, Indiana University
727 E. 3rd Street
Bloomington, IN 47405
Phone: (812) 855-5903
Fax (812) 855-5533
debeeker@indiana.edu

-----Original Message-----
From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On
Behalf Of Jerry DiMarco
Sent: Tuesday, February 20, 2007 6:45 PM
To: tap-l@lists.ncsu.edu
Subject: Re: [tap-l] Banana Plug Leads


There are replacement plugs for this type of cable. They have the
same look and don't need to be soldered. We did have to make a simple jig
(block with a hole in it) to assemble them. Got them from Newark, stock
no. 93F9164/...5 (red/blk)...


Jerry


At 11:54 AM 2/20/2007, you wrote:
>What I don't like about Pomona cables is that when an end breaks off
>(rare
>but it happens), it's very hard to fix, except by recycling like Santos
>does. I like the Pasco cables - they're a bit cheaper, the ends are very
>easy to re-attach, and the durability is just fine. We get the kit of
>parts and solder the cables to our own lengths. It's a great project for
>teaching my student assistants how to solder.
>-John


<><><><><><><><><><><><><><><><><><><><><><><><><><><><><>

Jerry DiMarco
Manager of Lecture Demonstrations and Instructional Labs
Montana State Univ., Physics Dept.

Bozeman, MT

Our Motto: "What would your mother do?"






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