Date: Thu Apr 5 12:34:42 2007

Author: Bill Norwood

Subject: Re: Wanted e/m App, Old S-W; Tubes; Fuses

Post:
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Hi Scott,



1. We have some tubes we bought new 4-5 years ago,

and I will find out whether we could sell you one.

But, since we haven't bought tubes for several years

I don't know yet whether our source has dried up.



2. While we use 8 of these e/m set-ups for 1 or 2 of the labs each semester
and summer,

we also have over a dozen others taking up excess space,

but the tubes have been scavenged from those units.

I will find out whether we could let some of these go,

in case you might need them,



3. We stopped burning out the filaments of the old Sargent Welch e/m tubes
4-5 years ago.

I experimented with fuse burn-out times vs. current,

and found that I could slightly overdrive a 3-1/2 amp fuse (they run hot)

and protect the filaments very well and only lose a fuse or two (on average)
each lab period.

(I could share the wordage provided the users for setting the filament
current while using these fuses.)



4. Your positive evaluation of this apparatus is instructive,

since I have questioned the wisdom of its continuation, given its
cumbersomeness.

Of course it's great for physical fitness, as we store these atop 84" high
cabinets!

Also, our home-made power supplies might be good as airplane weights during
storms.



Best Wishes,



Bill Norwood

U of MD Elementary Labs



-----Original Message-----
From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On
Behalf Of Scott Shelley
Sent: Thursday, April 05, 2007 11:42 AM
To: tap-l@lists.ncsu.edu
Subject: [tap-l] Wanted: Tubes for old Sargent-Welch e/m apparatus



Hello all,



I've just done a boneheaded thing and I'm hoping that some members of

this list can help me out.



We own seven of the beautiful old Sargent-Welch WL0623A e/m

apparatuses (circa 1960s?). I like these so much that I can't bear

to replace them with newer experiments, even though we don't have a

sufficient number to adequately outfit our labs. To remedy this

situation, I had my machinist manufacture two more devices, which I

was hoping to outfit with two extra tubes that we own.



Stupidly, I neglected to test these tubes and one of them has a

burnt-out filament. To compound the issue, another of the tubes

stopped working this year.



So, here's the dilemma: I've had my machinist build beautiful

duplicates of the WL0623As, but I don't have any tubes to put in

them. Before I give him bad news and ask him to alter his design to

accept some of the newer tubes on the market, I thought I'd write in

to see if any of you have extra tubes that you'd be willing to sell.



Thanks very much!



Scott Shelley

Haverford College.




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Hi =
Scott,



1. We have some =
tubes we
bought new 4-5 years ago,

and I will find =
out
whether we could sell you one.

But, since we =
haven't
bought tubes for several years

I don't know =
yet whether
our source has dried up.



2. While we use =
8 of
these e/m set-ups for 1 or 2 of the labs each semester and summer, =


we also have =
over a
dozen others taking up excess space,

but the tubes =
have been
scavenged from those units.

I will find out =
whether
we could let some of these go,

in case you =
might need
them,



3. We stopped burning out the filaments of the old Sargent Welch =
e/m
tubes 4-5 years ago.

I experimented with =
fuse
burn-out times vs. current,

and found that I could slightly overdrive a 3-1/2 amp fuse (they =
run
hot)

and protect the filaments very well and only lose a fuse or two =
(on
average) each lab period.

(I could share the wordage provided the users for setting the =
filament
current while using these fuses.)



4. Your =
positive evaluation
of this apparatus is instructive,

since I have =
questioned the
wisdom of its continuation, given its cumbersomeness. =


Of course it's =
great for
physical fitness, as we store these atop 84" high cabinets! =


Also, our =
home-made
power supplies might be good as airplane weights during =
storms.



Best =
Wishes,



Bill =
Norwood

U of MD =
Elementary Labs



-----Original
Message-----
From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On =
Behalf
Of Scott Shelley
Sent: Thursday, April 05, 2007 11:42 AM
To: tap-l@lists.ncsu.edu
Subject: [tap-l] Wanted: Tubes for old Sargent-Welch e/m =
apparatus



Hello =
all,



I've just done =
a
boneheaded thing and I'm hoping that some members of =


this list can =
help me
out.



We own seven of =
the
beautiful old Sargent-Welch WL0623A e/m

apparatuses =
(circa
1960s?). I like these so much that I can't bear =


to replace them =
with newer experiments, even though we =
don't have a

sufficient =
number to
adequately outfit our labs. To remedy this =


situation, I =
had my
machinist manufacture two more devices, which I =


was hoping to =
outfit with two extra tubes that we =
own.



Stupidly, I =
neglected to
test these tubes and one of them has a

burnt-out
filament. To compound the issue, another of the tubes =


stopped working =
this
year.



So, here's the
dilemma: I've had my machinist build beautiful =


duplicates of =
the
WL0623As, but I don't have any tubes to put in =


them. =
Before I
give him bad news and ask him to alter his design to =


accept some of =
the newer
tubes on the market, I thought I'd write in =


to see if any =
of you
have extra tubes that you'd be willing to =
sell.



Thanks very =
much!



Scott =
Shelley

Haverford
College.









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