The K&E 4082-3 Radio Special Slide Rule

The 4082-3 appears to be a variant of the 4081 with one scale changed. The K scale is replaced with the F scale. The F scale is a single unit logarithmic scale folded at the value of 2 pi and inverted. 1/(2pi) is used in common electronics calculations.

The 4082-3 does not appear in any K&E Catalog or price sheet that I have been able to obtain. The only proof of the existence of this rule is the actual samples and a sample of an instruction manual. The slide rule appears to have been produced from some time before 1939 to approximately 1943. There were 2 scale sets corresponding to the first two scale sets of the 4081. The first was not marked with a model number but had "Radio Special" in place of a model number. Actual samples of both of these models have been observed.

Scans of actual rules will be substituted for catalog pages.

1937 (Radio Special) Scale set:

1939 (4082-3) Scale set:

A manual was produced for the 4082-3 with the following title: "THE LOG LOG DUPLEX SLIDE RULE WITH F SCALE". The entire text of the manual is included here as it is the only documentation for the 4082-3 that is known to exist.