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Cardboard Engineering & Science Slide Rule Calculators
The Original Mobile Apps™

July 6, 2017 Update: Eight new cardboard slide rule calculators added, thanks to Neil Blaho. Some were from his father's collection dating back to the 1950s.

Long before there were smartphones and software 'apps,' engineers and scientists carried around portable 'apps' of another kind. These apps were made from printed heavy cardboard stock and typically had either a sliding section sandwiched between two outer layers, or a rotating layer on a fixed base layer. They even sported rivets to hold them together - like the original Levis dungarees. I and guys much older than me [ ;-) ] routinely carried them in our shirt pockets, securely snugged behind our plastic pocket protectors. You definitely always wrote your name on them in indelible ink since there was a tendency for those cardboard slide rules to sprout legs and walk away while you were at lunch or in the can.

These cardboard slide rule calculators used to be included on the Traditional Slide Rules page, but thanks to generous RF Cafe visitors who either sent me hard copies or high-res photos, the number has grown so large that they required their own page. You are invited to submit examples of your own collection for inclusion in the informal Cardboard Calculator Museum.

Varian Power Amplifier Calculator

Varian Power Amplifier Calculator - RF Cafe

Thanks to Neil Blaho for the donation
(copyright 1991)  Added July 6, 2017

Tecom Industries Antenna Calculations Slide Rule

Tecom Industries Antenna Calculations Slide Rule - RF Cafe

Thanks to Neil Blaho for the donation
(copyright 1976)  Added July 6, 2017

Shure Brothers Reactance Slide Rule

Shure Brothers Reactance Slide Rule - RF Cafe

Instructions Shure Brothers Reactance Slide Rule - RF Cafe

Thanks to Neil Blaho for the donation
(copyright 1957)  Added July 6, 2017

Scientific Atlanta Antenna Communications Systems Calculator

Scientific Atlanta Antenna Communications Systems Calculator - RF Cafe

Thanks to Neil Blaho for the donation
(copyright 1977)  Added July 6, 2017

REA Magnet Wire Co. Heavy Formvar Magnet Wire Slide Chart

REA Magnet Wire Co. Heavy Formvar Magnet Wire Slide Chart - RF Cafe

Instructions REA Magnet Wire Heavy Formvar Magnet Wire Slide Chart - RF Cafe

Thanks to Neil Blaho for the donation
(circa 1950s)  Added July 6, 2017

JFD Mfg. Co. Stroboscopic Disc

JFD Mfg. Co. Stroboscopic Disc - RF Cafe

Thanks to Neil Blaho for the donation
(circa 1950s)  Added July 6, 2017

itron Reciprocal Calculator

itron Reciprocal Calculator - RF CAfe

Thanks to Neil Blaho for the donation
(copyright 1968)  Added July 6, 2017

The Helipot Corporation Electrical Slide Rule

The Helipot Corporation Electrical Slide Rule - RF Cafe

Thanks to Neil Blaho for the donation
(copyright 1951)  Added July 6, 2017

Naval Surface Warfare Center: Electric Field Slide Rule

Naval Surface Warfare Center: Electric Field Slide Rule (side 1) - RF Cafe

Naval Surface Warfare Center: Electric Field Slide Rule (side 1) - RF Cafe

Thanks to Neil Blaho for the donation
(copyright 1991)

Scientific Atlanta: Antenna Calculator Slide Rule

Scientific Atlanta: Antenna Calculator Slide Rule (side 1) - RF Cafe

Scientific Atlanta: Antenna Calculator Slide Rule (side 2) - RF Cafe

Thanks to Neil Blaho for the donation
(copyright 1968)

Pacific Automation Products: Copper Wire Slide Rule

Pacific Automation Products: Copper Wire Slide Rule (side 1) - RF Cafe

Pacific Automation Products: Copper Wire Slide Rule (side 2) - RF Cafe

Thanks to Neil Blaho for the donation
(looks a little like the Starfleet Command logo)

Flam & Russell: Radar Cross-Section Cardboard Slide Rule

Flam & Russell: Radar Cross-Section Cardboard Slide Rule (side 1) - RF Cafe

Flam & Russell: Radar Cross-Section Cardboard Slide Rule (side 2) - RF Cafe

Thanks to Neil Blaho for the donation
(copyright 1968)

Hughes Electron Dynamics Division: Millimeter Wave System Calculator

Hughes Electron Dynamics Division: Millimeter Wave System Calculator (side 1) - RF Cafe

Hughes Electron Dynamics Division: Millimeter Wave System Calculator (side 2) - RF Cafe

Thanks to Neil Blaho for the donation
(copyright 1975)

muRata: Dial-a-Bead Selector Wheel

muRata: Dial-a-Bead Selector Wheel (side A) - RF Cafe

muRata: Dial-a-Bead Selector Wheel (side B) - RF Cafe

Thanks to Neil Blaho for the donation

Instrument Specialties Company: Shielding Design Guide "sticky fingers" Slide Rule

Instrument Specialties Company: Shielding Design Guide (side 1) Slide Rule

Instrument Specialties Company: Shielding Design Guide (side 2) Slide Rule

Thanks to Neil Blaho for the donation
(copyright 1982)

Honeywell: Signal Level Conversion Slide Rule Wheel

Honeywell Signal Level Conversion Slide Rule Wheel - RF Cafe

Thanks to Neil Blaho for the donation
(Annapolis, MD, was my childhood home town)

MegaPhase: Watts & Voltage Conversion Slide Rule

MegaPhase: Watts & Voltage Conversion Slide Rule (front) - RF Cafe

MegaPhase: Watts & Voltage Conversion Slide Rule (back) - RF Cafe

Thanks to Joe Cahak for the donation
(copyright 2009)

HP: HP 9000 Series 200 Memory Configuration Wheel

HP 9000 Series 200 Memory Configuration Wheel - RF Cafe

Thanks to Joe Cahak for the donation

HP: HP 9000 Series 300 Memory Configuration Wheel

HP 9000 Series 300 Memory Configuration Wheel - RF Cafe

Thanks to Joe Cahak for the donation

HP: Reflectometer & Mismatch Error Limits Calculator

HP: Reflectometer & Mismatch Error Limits Calculator (front) - RF Cafe

HP: Reflectometer & Mismatch Error Limits Calculator (back) - RF Cafe

Thanks to Joe Cahak for the donation
(copyright 1976)

AILTECH: Noise Slide Rule

AILTECH: Noise Slide Rule (front) - RF Cafe

AILTECH: Noise Slide Rule (back) - RF Cafe

Thanks to Joe Cahak for the donation
(copyright 1973)

Amphenol RF Division: Smith Chart Slide Rule

Amphenol RF Division: Smith Chart Slide Rule (front) - RF Cafe

Amphenol RF Division: Smith Chart Slide Rule (rear) - RF Cafe

Thanks to Joe Cahak for the donation

Andrew: Heliax Slide Rule

Andrew: Heliax Slide Rule - RF Cafe

Thanks to Joe Cahak for the donation

inmet: Gain Equalizer & Conversion Calculator

inmet: Gain Equalizer & Conversion Calculator (front) - RF Cafe

inmet: Gain Equalizer & Conversion Calculator (rear) - RF Cafe

Thanks to Joe Cahak for the donation
(copyright 1999)

Concise: Chemical Element Slide Rule

Concise: Chemical Element Slide Rule - RF Cafe

Thanks to Joe Cahak for the donation
(copyright 1968)

Microwave Development Labs (MDL): Rigid Waveguide Data Calculator

MDL: Rigid Waveguide Data Calculator (front) - RF Cafe

MDL: Rigid Waveguide Data Calculator (back) - RF Cafe

Thanks to Joe Cahak for the donation
(copyright 1995)

Miteq: Mixer Spur Analyzer Calculator

Miteq: Mixer Spur Analyzer Calculator (front) - RF Cafe

Miteq: Mixer Spur Analyzer Calculator (rear) - RF Cafe

Thanks to Joe Cahak for the donation

Rogers Corporation: High Frequency Substrate Selector

Rogers Corporation: High Frequency Substrate Selector (front) - RF Cafe   Rogers Corporation: High Frequency Substrate Selector (rear) - RF Cafe

Thanks to Joe Cahak for the donation
(copyright 2010)

Roos instruments: RF & Reactance Calculator

Roos instruments: RF & Reactance Calculator (front) - RF Cafe

Roos instruments: RF & Reactance Calculator (rear) - RF Cafe

Thanks to Joe Cahak for the donation
(copyright 1995)

Tektronix: Time Domain Reflectometer Slide Rule

Tektronix: Time Domain Reflectometer Slide Rule (front) - RF Cafe

Tektronix: Time Domain Reflectometer Slide Rule (rear) - RF Cafe

Thanks to Joe Cahak for the donation
(copyright 1972)

Control Components: Valve Sizing Calculator

Control Components Valve Sizing Cardboard Calculator - RF Cafe 

Thanks to Joe Birsa (N3TTE) for the donation
(copyright 1986)

Ohmart Corporation: Radiation Measurement Calculator 

Ohmart Corporation Radiation Measurement Cardboard Calculator - RF Cafe 

Thanks to Joe Birsa (N3TTE) for the donation
(copyright 1991)

Daniel Industries, Inc.: Air-Gas Orifice Flow Calculator

Daniel Industries, Air-Gas Orifice Flow Calculator - RF Cafe 

Thanks to Joe Birsa (N3TTE) for the donation
(copyright 1977)

The Ballentine Rule: dB <--> Ratio Conversion | Volts <--> dB Power Level

The Ballentine Rule - RF Cafe

Thanks to Gary Steinhour for the donation
(copyright 1953)

EM Laboratories: U.S. ↔ Metric Conversions

EM Laboratories: U.S. ↔ Metric Conversions - RF Cafe

Thanks to Gary Steinhour for the donation
(copyright 1975)

Tel-Instrument Electronics Corp.: AC Power Slide Rule

Tel-Instrument Electronics Corp. AC Power Slide Rule - RF Cafe

Thanks to Gary Steinhour for the donation
(copyright 1964)

FXR (now Microlab/FXR): Smith Chart Slide Rule

RF Cafe - FXR (Microlab/FXR) Slide Rule / Smith Chart (this is the Smith Chart side)RF Cafe - FXR (Microlab/FXR) Slide Rule / Smith Chart

Smith Chart Side

RF Cafe - FXR (Microlab/FXR) Slide Rule / Smith Chart (this is the slide rule side)RF Cafe - FXR (Microlab/FXR) Slide Rule / Smith Chart

Slide Rule Side
Thanks to Gary Steinhour for the donation)

APN-85 Pressure Reduction Computer

RF Cafe - APN-85RF Cafe - APN-85

I. Sea-Level Reduction (left), II. Altimeter Setting (right)
These were used by air traffic controllers back in the Stone Age This particular model was auctioned off when the Bedrock Airport closed
Thanks to Don Hicks for the donation

M/A-COM: VSWR Calculator

M/A-COM VSWR Calculator

M/A-COM VSWR Calculator

(copyright 1983)

Sage Wireline/Wirepac Calculator

Sage Wireline/Wirepac Calculator

Sage Wireline/Wirepac Calculator

Sage Wireline/Wirepac Calculator
(copyright 1992)

I have a spreadsheet available for the Wireline Calculator.

GE Mobile Radio Range and Transmitter Power Calculator

GE Mobile Radio Range and Transmitter Power Calculator - Front Side

GE Mobile Radio Range and Transmitter Power Calculator - Back Side

GE Mobile Radio, Range and Transmitter Power Calculator
(copyright 1977)
Thanks to Alan Kealey for the donation!

Andrew Microwave Antenna System Computer

Andrew Microwave Antenna System Computer

Andrew Microwave Antenna System Computer

Andrew Microwave Antenna System Computer
(copyright 1994)

Classic Format Slide Rules

Pickett N600 ES Log-Log Slide Rule

Pickett N600 ES Log-Log Slide Rule - the same model that the Apollo astronauts took to the moon with them

Original Pickett N600 ES Log-Log Slide Rule Box

Pickett N600 ES Log-Log Slide Rule Certificates

Pickett N600 ES Log-Log Slide Rule
(this is the same model that went to  the moon w/the Apollo astronauts)

K&E Model N4080-3 Log Log Duplex Trig

K&E Model N4080-3 Log Log Duplex Trig S/N 467192, Copyright 1947

K&E Model N4080-3 Log Log Duplex Trig, S/N 467192, Copyright 1947 Slide Rule
(wooden frame & bar w/metal ends)

K&E Model 4081-3 Slide Rule

K&E Model 4081-3 Slide Rule S/N 087105

K&E Model 4081-3 Slide Rule, S/N 087105
(wooden frame & bar w/metal ends)

Sterling 684 White Plastic Slide Rule

Sterling 684 White Plastic Slide Rule

Sterling 684 White Plastic Slide Rule
(I bought this for my first algebra class in 1976)

Skala Wilcza 32 Wooden Slide Rule

Skala Slide Rule - markings on leather case include "SP-NIA"  "PRACY" "WARSZAWA" "WILCZA 32"

Skala Slide Rule LogoSkala Wilcza 32 Wooden Slide Rule (Poland)
Thanks to Alan Kealey for the donation!

Pickett N1010-T Slide Rule

Pickett N1010-T Slide Rule - RF Cafe

Pickett N1010-T Slide Rule
(found in my father-in-law's basement)

Cleveland Institute 515-T Slide Rule

Cleveland Institute 515-T Slide Rule, made by Pickett

Cleveland Institute 515-T Slide Rule, made by Pickett

Cleveland Institute 515-T Slide Rule, made by Pickett

Cleveland Institute 515-T Slide Rule (made by Pickett)
Send me an e-mail if you want a PDF file of a partial (10 pages) copy of the instruction manual.
[Buy the complete manual set here]

Cleveland Institute 515-T Slide Rula Advertisement, August 1967 Electronics World - RF Cafe

This advertisement appeared in the August 1967 edition of Electronics World magazine. The unique slide rule, leather case, and 4-course instruction booklet was "...deliberately underpriced at less than $25."

K&E Beginner's Slide Rule

K&E Beginner's Slide Rule Model 4058C

K&E Beginner's Slide Rule Model 4058C

K&E Beginner's Slide Rule, Model 4058C
(all-wood frame & bar)

Lawrence Slide Rule Instruction Book

Lawrence Slide Rule Instruction Book

Lawrence Slide Rule Instruction Book
(copyright 1952)

Cleveland Institute of Electronics

Cleveland Institute of Electronics, Slide Rule Product Feature, January 1965 Popular Science

Cleveland Institute of Electronics Slide Rule Product Feature
January 1965 Popular Science

Other Interesting Slide Rule Configurations

From the International Slide Rule Museum website

Gong Se He Ying
Metalworking calculator for Iron materials

Slide Rule Wallpaper

Slide rule wallpaper

Slide Rule Wallpaper
Click on the image to open it in a new window, then right-click on it and choose Set as Background

Texas Magnum Slide Rule

Texas Magnum - World's Longest Slide Rule

Texas Magnum, World's Longest Slide Rule
(352 feet long, 300 pounds)

Soviet Slide Rule Watch

From the International Slide Rule Museum website

Soviet Slide Rule Watch

Projection Slide Rule

From the Slide Rule Guy website

Projection Slide Rule

RF Cafe Software

   Wireless System Designer - RF Cafe
Wireless System Designer

RF & EE Symbols Word
RF Stencils for Visio
Calculator Workbook
RF Workbench
Smith Chart™ for Visio
Smith Chart™ for Excel

About RF Cafe

Kirt Blattenberger - RF Cafe WebmasterCopyright
1996 - 2022
Webmaster:
Kirt Blattenberger,
 BSEE - KB3UON

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

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