Pickett & Eckel Model 500 Variations
(Click on images for details)
Model No. 500
1948
slide rule
slide rule		 Magnesium body/slide.

White number on black circle used on CI scale.

Note scale labeled "LLI" on left and "LL1" on right.
Model No. 500
1950
slide rule
slide rule
Model No. 500
1950
slide rule
slide rule		 Note: no mask numbers but otherwise identical to above.
Model No. 500
1951
slide rule
slide rule		 Note introduction of "<" for inverted scales and relabeling of LLn scales.
Model 500
1952
slide rule
slide rule		 First aluminum version.
Model 500-T
1954 ?
slide rule
slide rule		 Thin aluminum body.
Trig scales rearranged.

First version without serial number.

Model 500-T
1957 ?


Model 500-ES
1957 ?
slide rule
slide rule		 Grooved slide. Outside of rails still grooved for cursor.

Introduction of range values on LLn scale labels.

First version with slide tension springs.
Model 500-ES
1958
slide rule
slide rule
Model 500-T
1959
slide rule
slide rule		 Inverse scales in red.

Model N500-T
1960-61


Model N500-ES
1960-61
slide rule
slide rule		 The first N500's still have LL0 and LL00 scales.

And where did the red ink go?
Model N500-T
1962

Model N500-ES
1962
slide rule
slide rule		 Introduction of -LLn and DI scales.

Range values added to trig scales.

Range values moved on right end scale labels.
Model N500-ES
1962

Grantham Electronics Schools
slide rule
slide rule

Model N-500-T
1962-63


Model N-500-ES
1962-63
slide rule
slide rule		 Introduction of wide convex lenses.

Model N-500-T
1963-64


Model N-500-ES
1963-64
slide rule
slide rule

Model N-500-T
1964-?


Model N-500-ES
1964-?
slide rule
slide rule
Model N-500-ES
1964-?

Grantham Electronics Schools
slide rule
slide rule
[Back]