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Dave:. See if you can find a "Nuclear Bomb Effects Computer". Used by Dr. Strangelove to calculate the half-life of Cobalt-Thorium G.

I have several hundred different types, including paper ones, smith chart ones; slide rules for indexing x-ray diffraction patterns, and a cool nuclear bomb blast calculator - including radiation effects. I wish I had a Curta - that is on my list !

Thank you. I almost jumped out of my shoes when I saw it

That was a nice present

I still have a vest-pocket sized circular slide ruler down in the basement. Given to me by my high school science teacher, who insisted we learn the basics of a slide ruler before ‘graduating’ to a basic electronic calculator. Mastering a slide rule helped immensely in the understanding of exponents, trigonometry, etc. which proved invaluable in later years of high school, college, and grad school.
BTW, my first calculator had most of the scientific functions, and a very cool blue-green fluorescent 10-digit display. Sadly, it didn’t survive my hacking to make it run off of a DC adapter instead of battery power.

Nice find. Slide rules still have value. I have a small collection
gathered mostly on ebay.

I never found my late Fathers slide rule. his was a little wider than this
one. I am going to mound it on the Living room wall allong with his picture
and his 3 University degrees. I mounted a Abacus I bought. I think happy
thoughts when I look at that wall.

Martin

On Wed, Aug 10, 2022 at 4:51 PM Stan Gammons via groups.io <buttercup11421=
[email protected]> wrote:

On 8/10/22 18:32, John wrote:

What the heck kind of ruler is that!?

John

A slide rule.

It's been nearly 40 years since I used one. Not sure I still remember
how...

73

Stan
KM4HQE

nice

a slide rule

On 8/10/22 18:32, John wrote:

What the heck kind of ruler is that!?

John

A slide rule.

It's been nearly 40 years since I used one. Not sure I still remember how...

73

Stan
KM4HQE

Nice find!!!

Cheers,
Lyle
--
On Wed, 10 Aug 2022 14:54:56 -0700
"Martin Glazer" <mglazer2014@...> wrote:

--
73 NM6Y
Bickley Consulting West


"Black holes are where God is dividing by zero"


--
73? ?NM6Y
Bickley Consulting West Inc.


"Black holes are where God is dividing by zero"

The kind that designed the Mercury, Gemini, and Apollo Spacecraft!

What the heck kind of ruler is that!?

John

nice

On Wed, Aug 10, 2022 at 3:26 PM Dave W6OQ via groups.io <david.hostetler=
[email protected]> wrote:

I have a well maintained bamboo slide rule in a drawer somewhere here.
Never liked the metal ones. It got me through college to a BSEE, but
shortly after that, on my first full time engineering job at a small
company, the manager bought us one of the new HP pocket calculators to
share, then he added to the collection with newer models every year. Within
five years, I was able to purchase my own. Yes, it and a few other HP
calculators are around here somewhere as well.

K&E 4138? Log/Log Deci-trig?

I have a well maintained bamboo slide rule in a drawer somewhere here. Never liked the metal ones. It got me through college to a BSEE, but shortly after that, on my first full time engineering job at a small company, the manager bought us one of the new HP pocket calculators to share, then he added to the collection with newer models every year. Within five years, I was able to purchase my own. Yes, it and a few other HP calculators are around here somewhere as well.

Lucky you!!!!!

Remember, during the Manhattan Project at Los Alamos, the Slide Rule "made"
the first U and Pu supercritical masses happen. Trinity (New Mexico)
proved their worth.

I need to shop our local shops for just such a piece of nostalgia.

Dave - W?LEV

--
Dave - W?LEV

In addition to my last post, SWR / VSWR can be measured using either
voltage or current. If there is SWR / VSWR on the line, both will change
according to Ohm's Law. At any given point referenced other points along
the line, voltage goes up and current goes down and the voltage decreases
and the current increases - all keeping the power the same anywhere along
the line. The power measured anywhere along the line will remain constant
(neglecting losses) since, for a sine wave, power = voltage X current.

Dave - W?LEV

On Wed, Aug 10, 2022 at 9:58 PM W0LEV via groups.io <davearea51a=
[email protected]> wrote:

QUOTE: " So, you are saying that VSWR is based on voltage, but caused by
an impedance mismatch."

IF: Z(Source) = Z(XMSN Line) = Z(Load) There will be no standing waves
and the SWR / VSWR will measure 1:1.

If any of the three above individually move from the appropriate Z, there
will be standing waves and the SWR / VSWR will measure something other than
1:1.

If all of the three above coincidently move together to the identical Z's,
there will be no standing waves and the SWR / VSWR will measure 1:1.

Dave - W?LEV

On Wed, Aug 10, 2022 at 4:30 PM Russ <u.rusty@...> wrote:

On Wed, Aug 3, 2022 at 09:10 AM, Kenneth Hendrickson wrote:

If the load is not perfectly matched to the source, there will be a

voltage

standing wave ratio (VSWR) because of the mismatch.

So, you are saying that VSWR is based on voltage, but caused by an
impedance mismatch.

--
*Dave - W?LEV*
*Just Let Darwin Work*


--
Dave - W?LEV

--
*Dave - W?LEV*
*Just Let Darwin Work*


--
Dave - W?LEV

QUOTE: " So, you are saying that VSWR is based on voltage, but caused by
an impedance mismatch."

IF: Z(Source) = Z(XMSN Line) = Z(Load) There will be no standing waves
and the SWR / VSWR will measure 1:1.

If any of the three above individually move from the appropriate Z, there
will be standing waves and the SWR / VSWR will measure something other than
1:1.

If all of the three above coincidently move together to the identical Z's,
there will be no standing waves and the SWR / VSWR will measure 1:1.

Dave - W?LEV

--
Dave - W?LEV