| Name and Model Number | Keuffel & Esser 4082-3 “Radio” Slide Rule |
| Country of Origin | USA |
| Date of Manufacture | Pre 1940 |
| Front Scales | L LL1 DF [CF CIF CI C] D LL3 LL2 |
| Back Scales | LL0 LL00 A [B T ST S] D DI F |
| Scale Length | 25 cm |
| Type of Rule | Slide Rule |
| Construction | Duplex mahogany body with celluloid laminate scale surfaces. |
| Area of Use | Generic |
| Comment | This rule does not appear in the catalogs. The rule is a precursor to later rules tailored for electronics. The F scale is 1/2pi |
| Rarity | RRR |
| Donor | Collection of Clark McCoy |
| Match Number | 220 |
| Thumbnail (Click Picture for Details) |  |
| In conjunction with our 'donors' we assign a rarity rating to each item, based on the system devised by Herman van Herwijnen |
| (1929 - 2004), renowned Dutch collector, author, and creator of Herman's Archive, a collection of 5,000 slide rule images on CD. |
| • RR = Rare - 1 of 25 collectors has one; it may take a year to find an example in the marketplace. |
| • RRR = Very Rare - only a few known to collectors; may be several years before it comes up for sale. |
| • RRRR = Extremely Rare - a museum piece; unlikely that an example will come up for sale. |