National_Guard_operating_portable_radio_station_1922.jpg
Size of this preview:
776 × 599 pixels
.
Other resolutions:
311 × 240 pixels
|
622 × 480 pixels
|
995 × 768 pixels
|
1,280 × 989 pixels
|
1,344 × 1,038 pixels
.
Summary
Description National Guard operating portable radio station 1922.jpg |
English:
A portable military wireless station in 1922, operated by members of the 101st Signal Battalion, 2nd Corps, US National Guard Signal Corps, on field training near Peekskill, New York. Two guardsmen crank a hand-powered
electric generator
(left)
as a third
(center)
operates an early
vacuum tube
transmitter
sending text messages in
Morse code
using a
telegraph key
. The source (p. 58) says the equipment is an SCR-99, which can transmit on
wavelengths
between 900 m (330 kHz) and 1500 m (200 kHz). It uses VT-1 triodes for receiving and VT-2 triodes for transmitting, and has a range of about 100 miles with 320 V on the transmitting tubes.
Caption:
TRANSMITTING IN THE FIELD: The power for operating this equipment is furnished by the hand generator. Note the collapsible metal mast that serves as a support for an umbrella antenna
|
Date | |
Source | Retrieved August 27, 2013 from Alfred M. Caddell, "Radio fans who are paid to learn" in Popular Radio , Popular Radio Inc., New York, Vol. 2, No. 1, September 1022, p. 53 on Google Books |
Author | Alfred M. Caddell |
Licensing
Public domain Public domain false false |
This media file is in the
public domain
in the
United States
. This applies to U.S. works where the copyright has expired, often because its first
publication
occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See
this page
for further explanation.
|
||
This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the
rule of the shorter term
for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See
Wikipedia:Public domain
and
Wikipedia:Copyrights
for more details.
|