Diathermy_machine_1933.jpg
Size of this preview:
512 × 600 pixels
.
Other resolutions:
205 × 240 pixels
|
532 × 623 pixels
.
Summary
| Description |
English:
A German
diathermy
machine from 1933. This induced local deep tissue heating of the body by radio waves. Earlier "long wave" diathermy machines using Tesla coils had operated at around 0.5-2 MHz, which caused only general heating. "Short wave"
vacuum tube
diathermy machines like this which produced frequencies of 10-100 MHz were capable of more localized heating, and replaced them around 1930. Two capacitor plates are applied to the body, attached to the vacuum tube
oscillator
, and the oscillating voltage is applied to them, with the intervening body acting as the capacitor's dielectric.
|
| Date | |
| Source | Retrieved March 21, 2014 from E. Schliephake, "Ultra-short waves in medecine" in Short Wave Craft , Popular Book Corp., New York, Vol. 3, No. 11, March 1933, p. 646 on American Radio History website |
| Author | E. Schliephake |
|
Permission
( Reusing this file ) |
This 1933 issue of Short Wave Craft magazine would have the copyright renewed in 1961. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. [1] Search of the Renewals for Periodicals for 1960, 1961 and 1962 show no renewal entries for Short Wave Craft . Therefore the magazine's copyright was not renewed and it is in the public domain. |
| Other versions | 120 MHz Lecher line oscillator 1934.jpg |
Licensing
|
This work is in the
public domain
because it was published in the United States between 1929 and 1963, and although there may or may not have been a copyright notice, the
copyright was not renewed
. For further explanation, see
Commons:Hirtle chart
and
the copyright renewal logs
. Note that it may still be copyrighted in jurisdictions that do not apply the
rule of the shorter term
for US works (depending on the date of the author's death), such as Canada (70 years
p.m.a.
), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.
|
|