RCA Pindex - 1936 Double sided. Gives pin-outs and tube data for RCA Radiotron vacuum tubes on both sides with instructions on the back. Printed by Whitehead Hoag. Size: 6½" X 3" Larger Photo

RCA Victor Feature Finder RCA Victor Slide Chart for finding fearures on RCA models of Radios and Phonographs in their 1937 line-up. Two Sided Card produced by Whitehead-Hoag, Newark, New Jersey. Size: 6¾" X 2¾" Larger Photo

W. R. L. Tube Base Calculator - 1944 Gives vacuum tube characteristics and pins for finding tube substitutions. Reversible slide card has tube data on both sides. Chart of tube types on the back. Distributed by Wholesale Radio Laboratories, Council Bluffs, Iowa. Size: 11" X 4½" Larger Photo - Front Larger Photo - Back Photo - 1945 Envelope with WWII Victory Stamp.

Ohmite Ohms Law Calculator 1941, Double sided. On one side it has scales to compute ohms law along with volts and wattage required up to 1000 ohms. The second side covers the 1000 ohm to 10 megohm ranges. Instructions are printed on each side. Size: 9¼" X 4+" Larger Photo Envelope with color code charts

Ohmite Parallel Resistance Calculator 1949, Double sided. On one side it has several scales to compute Parallel Resistance. It also has a standard slide rule. The other side is an Ohms Law Calculator. Instructions are on slide. I have two versions of this © 1949 slide card. A cardboard version which has a price of 25 cents and a plastic covered version with a printed price of $2.50. Cardboard version once owned by Elmer Taylor (he printed his name on the slide). Size: 8¾" X 3" Larger Photo (cardboard version)

Ohmite Parallel Resistance Calculator 1970, Double sided. On one side it has several scales to compute Parallel Resistance. It also has a standard slide rule. The other side is an Ohms Law Calculator. Both faces have a clear vinyl cover. Instructions are on slide. Size: 9" X 3" Larger Photo

Ohmite Capacitor Calculator 1960, Double sided. On one side it has scales to compute frequency with effictive series capacitance, reactance and more. The second side has a range chart with formulas and a standard slide rule. Instructions are printed on the face. Size: 7¼" X 2¾" Larger Photo

Kester Solder Alloy Guide Kester Solder Alloy and Flux Selector slide card. Solder guide on one side and Flux Selector on reverse. Shows melting point of various solder alloys. Card produced by the Graphic Calculator Company, Barrington, Illinois. I'm guessing around 1974. Approx. Size: 6½" X 3¼" Larger Photo (front and back) Also check out my Soldering Iron Collection

Allied Radio Resistance Capacitance Calculator Six Wheel, Double sided and has different ranges on each side. Size: 12½" X 3½" Larger Photo Paper Cover Instructions (Adobe PDF File)

Allied Radio Coil Winding Calculator Double sided. On one side it has several scales to compute coil Inductance and uses coil length, diameter, wire size, turns per inch, etc. The other side calculates R-F Resonance and Ciol Winding. It has scales for frequency/wavelength and Inductance/Capacitance. Size: 10" X 5" Larger Photo Paper Cover Instructions (Adobe PDF File)

"The Ballantine Rule" 1953 This slide chart by Ballantine Laboratories has a DB - Ratio conversion scale on one side and a Volts - DB power level converter on the other. The Ballantine Voltmeter Scale Reference card with it has a scale to compare voltage ratio and decibels. Cards produced by the Perry Graph Corp. Slide Size: 8½" X 3" Card Size: 3¾" X 2¼" Larger Photo Instructions (Adobe PDF File)

Amphenol RF Connector and Cable Selector - 1954 This is a spiral bound, double slide card. There are two cards that are attached like a spiral notebook. One card is a slide chart for selecting the proper Amphenol RF connector and cable, the second card provides a cross reference to RF cable, and cable assemblies. Card produced by the Perry Graph Corp. Size: 9½" X 4¼" (closed) Larger Photo Photo of second side

Ampex Stereo-Graph - 1959 Ampex Stereo-Graph slide chart of basic control settings for the Ampex 960 Stereophonic Tape Recorder/Reproducer. Reverse calculates tape playing time by reel size and tape thickness in feet, hours, and minutes. Card produced by the Perry Graph Corp. Size: 9¼" X 4" Larger Photo

GE Range and Signal Strength Calculator - 1952 This General Electric slide chart is double sided with a plastic cover over a cardboard slide card. Front has slide chart for antenna height to key number and reverse has slide chart for megacycles and signal in microvolts along with key number calculated on front. Card produced by the Perry Graph Corp. Size: 6½" X 2" Larger Photo Photo of storage sleeve

Motorola Zener Diode Calculator 1959 This Motorola slide chart calculates volts, amperes, and wattage of Zener Diodes. Back has a chart for selecting the proper Motorola Zener Diode by nominal/tolerance voltages. Instructions are on paper sleeve. Card was produced by the Perry Graph Corp. Size: 12" X 4¾" Larger Photo Instructions (Adobe PDF File)

1953 Sprague T-C Rule Slide chart for finding the values of N750 and NPO type ceramic capicitors needed for paralled circuits.The reverse side lists color codes and locations for ceramic capacitors. Approx. Size: 6¼" X 3" Larger Photo

Shure Reactance Slide Rules 1942 Here are two slide cards from Sure Brothers Inc. These double sided slide cards were used to calculate the resonant frequency equation for microphones. On one side they have scales to calculate capacity, inductance, and frequency. The other side has scales for capacitive reactance and inductive reactance. These cards were produced for Shure by the Perry Graph Corp. Approx. Size: 8½" X 3½" Front Reverse Instructions (Adobe PDF File)

DuMont Picture Tube Selector 1954 DuMont Picture Tube Selector Two Sided Slide Chart Size: 8½" X 3" Larger Photo (Both Sides) Chart produced by the Perry Graph Corp.

RCA TV Picture Tube Replacement Guide 1964 RCA Silverama Colorama Replacement Picture Tube Guide and Industry Interchangeability Guide Two Sided Card produced by Whitehead-Hoag, Newark, New Jersey. Size: 12" X 4¾" Larger Photo Replacement Classification Key Produced by the Perry Graph Corp.

GE Fluorescent Lighting Calculator 1946 GE Fluorescent Lighting Calculator This two sided General Electric slide chart has two sliders which may be adjusted independently of each other. Size: 7" X 3" Larger Photo - Front Front, Back, Sleeve

Westinghouse Motor and Control Selector Two sided Westinghouse Motor and Control Selector Slide Chart. No date Size: 6¼" X 2¾" Larger Photo - Front and Back

Anaconda Transmission Line Slide Rule This 1943 Anaconda Wide-Band Transmission Line Slide Rule calculates wave magnitude, phase, and ratio of voltage to current along transmission lines. Produced by the Perry Graph Corp. Size: 13" X 5" Larger Photo - Front Larger Photo - Back Instruction book

General Cable Calculator Slide Chart 1940 General Cable Calculator - This two sided General Cable slide chart calculates wire and conduit size for current needed. Front is for new installations and rear is for rewiring. Produced by the Perry Graph Corp. Size: 6½" X 3" Larger Photo - Front and Back

Fenwal Thermistor Computer 1966 Front slide chart calculates resistance at various tempaturer points. Has scales for current, voltage, and resistance ranges. Reverse side has seven scales bases on resistance teperature curve. Produced by the Perry Graph Corp. Approx. Size: 6½" X 9" Front Reverse

Engineering Slide Chart - Current This "Great Innovations" slide chart is a comprehensive Screw Chart that includes technical information from many of the quick references that are commonly found in the work areas of designers, engineers, and machinists. All of this information is compiled for both English and Metric systems in a single screw chart. More information: engineeringslidechart.com Approx. Size: 11" X 8 7/8" Larger Photo