Technical Information on Crystal Radio Design, Late 1920's TRF Radios, Antique carbon-type Hearing Aids and Blonder-Tongue Labs

A:  Original Technical Articles Relating to Crystal Radio Set Design may be found here. Many have application to areas other than crystal radios such as diode detector loss, measurement of diode SPICE parameters, inductor and capacitor Q, headphone impedance and loss measurement, audio transformer loss and measurement, along with many tutorial notes.

B:  The Edison Company entered the radio field early in 1929, in an attempt to reverse a drastic downturn in their home entertainment phonograph business. About three-quarters of a year later, because of increasing losses, they closed the phonograph part of their home entertainment business to concentrate on radios.  Unfortunately, the radio effort did not live up to expectations, and was closed at the end of 1930.  Many of these documents were copied directly from the originals in the Edison National Historic Site: Minutes of internal meetings related to radio design and manufacturing, User and Service data on Edison Radios, copies of advertisements, and Corporate Annual reports of the Radio Division (Splitdorf Radio Company).

C:  Radio Receivers for the home reached their peak of development in the 1928-1929 time frame. Technical performance data and the IRE Measurement Standard as of 1929 may be found here.

D:  Interesting Information about Antique Hearing Aids includes user manuals for Acousticon carbon-type electric hearing aids from about 1926 and articles from Radio-Craft magazine of Oct 1938 about Hi-Fi hearing aids and hearing aid testing methods.

E:  About Blonder-Tongue Labs and Ben H. Tongue

F:  Links related to crystal set design and construction, component suppliers, a Museum collection of antique wireless and scientific instruments, Electronic Engineering resources, some clubs and more.

Copyright notice:
Everything on my site is copyright 1999-2009, Ben Tongue. All rights are reserved. If you wish to use anything on this site (pictures, text, downloads) for non-commercial purposes, please ask. It is highly likely that I will say yes. Ben H. Tongue

This page published: 10/04/2006; Revised 06/19/2009
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