July 1936 Radio-Craft
People old and young enjoy waxing nostalgic about and learning some of the history of early electronics.
Radio-Craft was published from 1929 through 1953. All copyrights are hereby acknowledged. See all articles
really was not all that long ago when wiring images for news stories literally meant transmitting
photographs over a twisted pair of telephone lines either to a fax machine or to a computer on
standby waiting for incoming files. Videocasts were being regularly performed via satellite of
ground relay microwave stations since the 1960s, but most still shots were sent via phone lines. For
the last decade and a half, both still shots and videos have been transmitted as a routine matter
via camera-equipped cellphones, and as with most technologies we have quickly become so accustomed to the
convenience that memories of the old ways are quickly (even thankfully) forgotten. This article from
a 1936 edition of Radio-Craft describes one of the really early systems. Notice that
coupling to the telephone line is via induction to the handset, not via a hardwire connection to the
phone circuit. The thumbnail on the left links to a 1940 news story in the Monroe, Louisiana
News-Star newspaper boasting of its newly acquired telephone photo system.
Sending Pictures by Telephone
A newly-perfected system for sending news photos over ordinary telephone
lines is here described. The portable transmitter is not connected directly to the line but is merely
placed close to the telephone instrument. A "picture" may be telephoned at night from coast to coast
for only $25!
One of the most important aids to the modern high-speed dissemination of pictures of news events
has come to light recently with the release by the New York Times of data on a system of wire transmission
of photos, developed by its subsidiary, Wide World Wired Photos. This new method employs the wires of
the telephone companies, and in some cases those of the telegraph carriers as well, without actual connection
to the circuit. The impulses from the portable transmitter are transferred to the lines by induction
only, and will function anywhere there is an ordinary telephone line, which is the feature that makes
its field so enormous.
Fig. A. - The portable transmitter in use. Note hand held over transmitter.
The transmitters, as seen in Fig. A, are of the portable type, and weigh about 50 lbs., packed in
their carrying cases, which are not much larger than a good-size suitcase. If operation is to be accomplished
at a point where line power is not available, the equipment may be operated from any 6 V. source, such
as a storage battery. A 15-lb., airplane-type battery will supply sufficient current to transmit 8 full-size
(7 1/4 x 8 3/4 in.) images or "pictures."
Fig. B. - An example of a transmitted picture.
The receivers, as seen in Fig. C, are of the rack type since they need not be portable, and may be
operated in either light or dark locations.
Fig. C. - Rack-type receiver; note image cylinder.
Actual operation of both transmitters and receivers is very simple. An ordinary glossy photo is secured
to the drum of the transmitter, which in operation revolves 45 times per minute. As it turns, a spot
of light photo to a photo-cell, the resulting current being combined with an 1,800-cycle signal. This
combination signal is then amplified and applied inductively to the line. (It is only necessary to cover
the transmitter of the telephone instrument, so as to prevent pick-up of external noise.) An ordinary
station-to-station call is then made over the telephone to the newspaper office; (later, use may be
made of the "conference wires" whereby the pictures may be sent from one point and received simultaneously
at several different cities).
Fig. D. - Note the remarkable detail.
At night rates, a 6 1/2 x 8 1/2 ins. picture would cost a maximum of about $25.00 if sent from coast
to coast, and could be sent in about 15 mins.
The receiving end operates almost as simply. The operator places a drum carrying a sheet of sensitized
paper upon a vertical spindle on the panel. A pick-up coil placed close to the telephone instrument
is connected to the amplifying system of the receiver, and the amplifiers and synchronizer adjusted,
the latter process being extremely simple.
While the process is somewhat similar to that used by other news systems, it differs in several important
points, one of the most radical departures of course, being that the portable transmitters may be used
anywhere there is an ordinary telephone line available. Another difference is that the new apparatus
is so well synchronized that perfect pictures may be sent over the "carrier circuits," used quite extensively
in the Southwestern portion of the U. S. Transmission over these circuits heretofore has resulted in
such distortion that the pictures were totally unusable.
The perfection of the transmissions may be seen by reference to Fig. B, which shows an unretouched
photo of a railroad wreck as reproduced over the system; and Fig. D, also unretouched illustrating an
actual "news" occurrence.
Fig. 1. The 3 steps. First the picture is taken, then developed; second, it is sent
over the line; and third, received (as shown in Fig. D at the newspaper office.
In Fig. 1, our artist has shown the sequence of operation. First the reporter snaps a picture of
a wreck, which is then quickly developed, and transmitted over the telephone in the village general
store. The reader will easily understand the importance of this rapid system in the dissemination of
illustrated news stories.
Posted March 29, 2016