45122

Re: base-2 mega & giga
Gentlemen, Approximations of this variety seem to have stopped being taught about the time I hit High School. Every time I see "The list can go on" I salivate.

William Brohinsky

6:32 PM

#45122
45121

Re: base-2 mega & giga
I would love to see some of the trig approximations. (As many as you can find?) These are the little extras which made sliderules much more useful than most

Charles Quinlan

6:31 PM

#45121
45120

Sighting - Cosmos
This week's episode covers the life of Clair Patterson, investigating lead contamination in the environment as a byproduct of his research into determining the

mjbauer001

6:29 PM

#45120Fetching Sponsored Content...

45119

Re: Spirule
The Spirule is a fun toy, .... errr... tool. I have mine from my control systems course at Virginia Tech and got another from eBay that I plan to pass on to

Ron McConnell

6:28 PM

#45119
45118

Spirule
I have an original Spirule with original instructions and a copy of Walt Evan's book "Control System Dynamics" which has an Appendix devoted to the use of his

garco325@att.net

Apr 21

#45118
45117

Re: base-2 mega & giga
this approximation is a particular case of : general approximation (1+x)^n = 1+nx if x is fairly small compare to 1. in your case (1+(-x))^(-1) = 1 +

Fabrice 94

Apr 21

#45117
45116

Re: base-2 mega & giga
Back before computers and hand held calculators, the use of approximations or the teaching of such was very common. I recall in my undergraduate days learning

sliderulenut

Apr 20

#45116
45114

Re: base-2 mega & giga
Thanks!!!! I had not thought about using this "approximation" rule, but it sure hit the spot for some calculations I was doing... and, just in time. Q ... On

Charles Quinlan

Apr 19

#45114
45113

base-2 mega & giga
Applying Moore's Law on a slide rule recently, I needed a value for 2^20, the base-2 "mega". Of course in many cases one million is close enough, but I wanted

Paul Hirose

Apr 18

#45113
45112

Re: ST introducrtion
Thanks, Clark, sorry for the delay. I didn't mean to imply that Rietz was the first to use the CI scale. I only meant that he added the CI to his scale

sliderulenut

Apr 18

#45112
45111

Re: ST introducrtion
Thanks, Steve, I came to that conclusion a few hours ago. I used m which is the common nomographic term for modulus or length of the scale being used. marion

sliderulenut

Apr 17

#45111
45110

Re: ST introducrtion
Hi Marion, This equation would be to calculate the distance from the left index, where L is the total scale length. Using 1.8 keeps the argument of the log

Steve Treadwell

Apr 17

#45110
45109

Re: ST introducrtion
Chris Redding some time ago used the expression d = L*log[x*pi/1.8]. Where does this come from? It seem strange to use 1.8 instead of 180 which is the proper

sliderulenut

Apr 17

#45109
45108

Re: ST introducrtion
It would probably be best to use the radian as the basis for the ST or SRT scale as the tangent converges toward x from greater than x as x becomes much less

Maynard Wright

Apr 16

#45108
45107

Re: ST introducrtion
Thanks! Q ... On Wed, 4/16/14, Steve Treadwell wrote: Subject: Re: SR ST introducrtion To: sliderule@yahoogroups.com Date: Wednesday,

Charles Quinlan

Apr 16

#45107Fetching Sponsored Content...

45106

Re: ST introducrtion
Which would make sense as the trig scales are based on the "unit circle" and the measure of the arc would be more accurate at that small an angle. Q ... On

Charles Quinlan

Apr 16

#45106
45105

Re: ST introducrtion
It seems that different manufacturers used different values - some used the radian, some the sine, and some an intermediate value. Go to the group web site

Steve Treadwell

Apr 16

#45105
45104

Re: ST introducrtion
And FR wrote definitely arc0.01x for ST scale, and there are two small marks by 6° left for sine and right for tangent. Zoltán On Wednesday, April 16, 2014

Zoltán

Apr 15

#45104
45103

Re: ST introducrtion
That is why K&E called it the SRT scale after 1955 on their decimal-trig rules after 1955. Clark From: sliderule@yahoogroups.com

Clark

Apr 15

#45103
45102

Re: ST introducrtion
I haven’t got any written proof but as far as I know the ST scale is neither sine nor tangent, it’s the length of the arc: sin5.5°=0.09585 ≈

Zoltán

Apr 15

#45102
45101

Re: ST introducrtion
Hi Marion I had not thought about the origin of the ST scale. K&E did not use it until the introduction of the 4080-3 and 4081-3 in 1936. K&E first put a CI

Clark

Apr 15

#45101
45100

ST introducrtion
Does anyone know what scale factor was used on the original introduction of the ST scale? I understand Dr. Rietz introduced the ST scale around 1925 or 1929 on

sliderulenut

Apr 15

#45100
45099

Re: Spare Parts and Trading
Thanks all for your suggestions. This is a wonderful group. Tom Wetmore

Thomas Wetmore

Apr 11

#45099
45098

Re: Spare Parts and Trading
Tom, If you just want to buy a cursor you can try here: http://srtco.us He has some K&E parts - a window for your 4083 lists for $16. I've bought parts and

Steve Treadwell

Apr 10

#45098
45097

Re: Spare Parts and Trading
Hi Tom If you are just looking for the glass I have 6 to 8 pieces for that frame size. They are used but in good condition. Clark McCoy From:

Clark

Apr 10

#45097
45096

Re: Spare Parts and Trading
Tom, I have recently seen on Ebay an advertisment for replacment cursor windows that I believe are for that size rule. I seem to remember an asking price

Not Here

Apr 10

#45096
45095

Re: Spare Parts and Trading
There is/was a guy on eBay selling decent repro parts for K&E. I've bought some cursors, etc. and was very satisfied. Hans.

Hans E. Hansen

Apr 10

#45095Fetching Sponsored Content...

45094

Spare Parts and Trading
I'm a new member and a relatively new collector. I have about 30 rules, concentrating on K+E, but with representatives from other manufacturers. I have a

ttwetmore

Apr 10

#45094
45093

Re: Slide rule simulations
Not exactly simulation software, but I have online virtual rules for Sun-Hemmi 153 K+E 4093-3 K+E Analon

Mark Armbrust

Apr 8

#45093
45092

Re: Slide rule simulations
You can try the entire collection at: http://www.hercsmusicsystems.com/sliderule.html

Robert Wolf

Apr 8

#45092
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