May 1959 Electronics World
Table of Contents
Wax nostalgic about and learn from the history of early electronics. See articles
from
Electronics World, published May 1959
 December 1971. All copyrights hereby acknowledged.

Even after computers became
commonplace in cubicles and laboratories, engineers and technicians kept design
nomographs around for cobbling together attenuators, filters, voltage dividers,
etc. Trade and hobbyist magazines like Electronics World used to print
them as fullpage features on a regular basis, and I have posted many of them on
RF Cafe over the years. This particular "Symmetrical T & H Attenuator Nomograph"
appeared in a 1959 issue. Maybe the editor thought that "Symmetrical T, H, O,
and Pi Attenuator Nomograph" would be too long of a title and that's why the "O" and
"Pi" was omitted even though they are clearly included in the chart. As can
be seen by inspection of the circuit constructions, the T and Pi configurations
(top row)
are "unbalanced" while the H and O configurations (bottom row) are "balanced." A
quick WWW search turns up plenty of attenuator design apps that not only solve
for the exact theoretical values of resistors but also will select the nearest
standard value resistors. Some will even then calculate the resulting
attenuation value based on those nonexact resistor values.
Symmetrical T & H (and O and Pi) Attenuator Nomograph
Nomographs / Nomograms Available on RF Cafe:

Parallel Series Resistance Calculator 
Transformer Turns Ratio Nomogram 
Symmetrical T and H Attenuator Nomograph 
Amplifier Gain Nomograph 
Decibel
Nomograph 
Voltage and Power Level Nomograph 
Nomograph Construction 
Nomogram Construction for Charts with Complicating Factors or Constants

Link Coupling Nomogram 
MultiLayer Coil Nomograph

Delay Line Nomogram 
Voltage, Current, Resistance, and Power Nomograph 
Resistor Selection Nomogram 
Resistance and Capacitance Nomograph 
Capacitance Nomograph 
Earth
Curvature Nomograph 
Coil Winding Nomogram 
RC TimeConstant Nomogram 
Coil Design
Nomograph 
Voltage, Power, and Decibel Nomograph 
Coil Inductance Nomograph 
Antenna Gain Nomograph

Resistance and Reactance Nomograph 
Frequency / Reactance Nomograph
Posted July 1, 2019
