The American Radio Relay League (ARRL) sold a variety of these
"Lightning Calculator" slide rules in the days before electronic calculators. This
"Type B" version (copyright 1932, W.P. Koechel) calculates Ohm's Laws values
for resistance, voltage, current, and power. As shown here, it indicates an alignment
of 1 V, 1 A, and 1 Ω. The Lightning Calculators" were rather
large at 8½" wide by 11" high. Being the size of a sheet of paper, it is
surprising they did not come with holes for a 3ring binder. There were six varieties
of "Lightning
Calculators," as shown in the 1939 QST magazine advertisement. Thanks to
Joe Birsa (N3TTE) for the donation  Added October 19, 2020
Thanks to Neil Blaho for the donation (copyright 1957)
Added July 6, 2017
Thanks to Neil Blaho for the donation (circa 1950s)
Added July 6, 2017
Thanks to Neil Blaho for the donation (copyright 1968)
Added July 6, 2017
Thanks to Neil Blaho for the donation (copyright 1991)
Thanks to Neil Blaho for the donation (Annapolis, MD, was
my childhood home town)
Thanks to Neil Blaho for the donation (copyright 1968)
Thanks to Neil Blaho for the donation
Thanks to Joe Cahak for the donation
Thanks to Joe Cahak for the donation
Thanks to Joe Cahak for the donation (copyright 1973)
Thanks to Joe Cahak for the donation
Thanks to Joe Cahak for the donation (copyright 1999)
Thanks to Joe Cahak for the donation
Thanks to Joe Cahak for the donation (copyright 1972)
Thanks to Joe Birsa (N3TTE) for the donation (copyright
1991)
Thanks to Joe Birsa (N3TTE) for the donation (copyright
1977)
Thanks to Gary Steinhour for the donation (copyright
1975)
Smith Chart Side
Slide Rule Side Thanks to Gary Steinhour
for the donation)
Sage Wireline/Wirepac Calculator (copyright 1992)
I have a spreadsheet available for the
Wireline
Calculator.
Andrew Microwave Antenna System Computer (copyright
1994)

Thanks to Ken H. for the photos of his
Nuclear Bomb
Effects Computer (likely the original 1957 version), produced by The Lovelace Foundation and
EG&G. "This Nuclear
Bomb Effects Computer has been compiled in cooperation with the
Atomic Energy Commission,
Division of Biology and Medicine, and Lovelace Foundation for Civil
Effects Test Operations AECBiology And Medicine Contract AT(291)1242." Quickly
and handily calculates Max. Fireball Radius, Height for Minimal Fallout,
Apparent Crater Radius and Depth, and even Radiation Levels with 1st, 2nd, and
3rd degree burns! Who wouldn't have wanted one of these back in the 1960s while
hunkering down in an underground bunker or beneath your school desk while
thermonuclear ordinance was exploding overhead? Added April
11, 2022
Thanks to Neil Blaho for the donation (copyright 1991)
Added July 6, 2017
Thanks to Neil Blaho for the donation (copyright 1976)
Added July 6, 2017
Thanks to Neil Blaho for the donation (copyright 1977)
Added July 6, 2017
Thanks to Neil Blaho for the donation (circa 1950s)
Added July 6, 2017
Thanks to Neil Blaho for the donation (copyright 1951)
Added July 6, 2017
Thanks to Neil Blaho for the donation (copyright 1968)
Thanks to Neil Blaho for the donation (looks a little like
the Starfleet Command
logo)
Thanks to Neil Blaho for the donation (copyright 1975)
Thanks to Neil Blaho for the donation (copyright 1982)
Thanks to Joe Cahak for the donation (copyright 2009)
Thanks to Joe Cahak for the donation (copyright 1976)
Thanks to Joe Cahak for the donation
Thanks to Joe Cahak for the donation (copyright 1968)
Thanks to Joe Cahak for the donation (copyright 1995)
Thanks to Joe Cahak for the donation (copyright 2010)
Thanks to Joe Cahak for the donation (copyright 1995)
Thanks to Joe Birsa (N3TTE) for the donation (copyright
1986)
Thanks to Gary Steinhour for the donation (copyright
1953)
Thanks to Gary Steinhour for the donation (copyright
1964)
(copyright 1983)
I. SeaLevel 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
GE Mobile Radio, Range and Transmitter Power Calculator (copyright
1977) Thanks to Alan Kealey for the donation!
