Slide rules

Acquired some slide rules this week (that makes three that I have now, so I think that qualifies as a collection). The new additions came from the estate of N6GA (SK) and were posted on one the amateur radio mailing lists I subscribe to. Both came in hard cases and are in pretty good condition.

Slide rules
Keuffel & Esser (K&E) 4080-3 log-log slide rule (top) and Pickett N-515-T Cleveland Institute of Electronics electronics slide rule (bottom)

The Keuffel & Esser 4080-3 slide rule has a serial number of 939707 (some nice symmetry in that number). Looks like this is a 1939 version, based on the scales on the rule and this catalog page.

The plastic brace parts of the reticle are broken, and there’s some corrosion on the metal frame. Think it might be possible to fashion some replacement braces out of bamboo or something similar. Looks like I might be able to purchase a used one too. No manual for this one, so I’ll have to see if I can hunt one down.

The other slide rule is a Pickett N-515-T. Seems like this particular model was made by Pickett for the Cleveland Institute of Electronics. Has some scales specifically for electronics related calculations and handy electronics formulas printed on the back. Not quite as chunky as the K&E slide rule, but it’s made of metal (aluminum I think) so it’s pretty rugged. No manual with this one either, but I was able to find some Cleveland Institute of Electronics slide rule course booklets online.

Will be fun learning how to use these slide rules.