Full Details

Name and Model Number K&E 4138 Morrison Radio Rule
Country of Origin USA
Date of Manufacture  
Front Scales L F A = B CI C = D T ST S
Back Scales 9 8=7 6 5 4 = 3 2 1
Scale Length 10 ins
Type of Rule Slide Rule
Construction Mahogany celluoid, glass cursor
Area of Use Electrical
Comment Designed for radio electronics, the slide rule has 9 specific scales to solve a variety of problems.
Reverse Scales:
1 dB decibels
2 E field intensity
3 s soil conductivity
4 f frequency
5 P Power
6 Ed field intensity x distance
7 d distance
8 & 9: Attenuation factor
Rarity RRRR
Donor Collection of Wayne Harrison
Match Number 405
(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.