Skip to content


This Week in CECOM History – West Point Radio Club

Mr. Joseph O. Wilson, Technical Intelligence Coordinator, explains various circuit systems of Signal Corps equipment to Cadet members of the West Point Radio Club, who were touring the Hexagon at Fort Monmouth, NJ. 8 May 1955

CE Museum Photo# 1213

CE Museum Photo# 1213

 

 

Posted in From the Archives, This Week in CECOM History.

Tagged with , , , , .

Read Comments


Before Things Were Wireless – This Week in CECOM History

Wire laying device invented by the wire-laying detail of the 2nd Signal Company, 2nd Division. This device is capable of picking up six to seven miles of wire per hour when installed in a moving truck and allows its operator to view the beauties of the surrounding country as he pedals along. It consists of a wooden frame supporting two standard half-mile wire reels connected by a bicycle chain and sprocket to an old bicycle frame which is pedaled by one man while another guides the wire onto the reels. Fort Sam Houston, TX. April 1931.

CE Museum Photo #2377

CE Museum Photo #2377

Posted in This Week in CECOM History.

Tagged with , , , , , .

Read Comments


This Week in CECOM History – Facsimile

Facsimile Receiver under test by Signal Corps personnel. This device was used successfully in Air Corps Maneuvers at Mather Field, California. 24 April 1930.

3791

Posted in This Week in CECOM History.

Tagged with , , .

Read Comments


Floraphone Update – This Week in CECOM History

This blog highlighted a photograph on 27 March 2014,  showing MG George Owen Squire (copied below) that is dated 17 April 1919. Since that time we’ve learned a little more about the ideas behind the “Floraphone.”

In April 1919, Major General George Owen Squire, Chief Signal Officer and the man responsible for locating the Radio Laboratories at Fort Monmouth, attracted attention by using trees as radio antennas. He drove a spike into the trunk of a tree on the outskirts of Washington, D.C. and picked up signals from Germany. He called such messages “floragrams,” and the tree-telegraph was described as a “floragraph”; the receiver a “floraphone.”

This new idea was featured in Scientific American in the 14 July 1919 edition, as well as the Electrical Experimenter from July 1919.

So the next time you see one of those cell-phone towers disguised as a tree, you can remeber that we once used real trees as antennas.

Image # 0587

Image # 0587

Posted in From the Archives, Squier's Stories, This Week in CECOM History.

Tagged with , , , , .

Read Comments


This Week in CECOM History – Army Day 1949

Showing pigeons to public during Army Day, on 9 April 1949, Sgt. Harry Lucas from the Ft. Monmouth lofts on the right.

The pigeon program was headquartered at Fort Monmouth from the end of World War I until the program was discontinued in 1957.

CE Museum Photo #3543

CE Museum Photo #3543

Posted in This Day In History, This Week in CECOM History.

Tagged with , , .

Read Comments


AN/GRC-106A Radio Set

From time-to-time, this blog feature will present its readers with information related to more-or-less random pieces of equipment. This “series” of blogs generally will focus on Radios, but may on occasion venture into other equipments and apparatus. This blog features the AN/GRC-106A Radio Set.

AN GRC-106 A Image

The AN/GRC-106A was a vehicular mounted radio communications set used in combat areas, from battalion to field army. Originally designed to extend the range of voice communications, this radio was also employed as the basic radio for medium range radio-teletypewriter communications. The AN/GRC-106A was also compatible with manpack equipment used by foot soldiers.

The predecessor to the AN/GRC-l06A was the basic single sideband radio set, AN/GRC-106. The AN/GRC-106 radio was developed to provide combat units with a series of radio sets affording reliable voice, continuous wave and teletypewriter communications. The AN/GRC-l06A featured improved tuning characteristics that allowed for a reduction of the required channel separation from 1 KHz to 100 Hz permitting the 106A to utilize 10 times as many channels as its predecessor.

The AN/GRC-106A was an ultra-rugged single sideband transistorized radio set designed mainly for vehicular mount. The system was composed of two major units 1) Receiver-Transmitter RT-834/GRC, and 2) Radio Frequency Amplifier AM-3349/GRC-106 which were contained in two sealed cases to protect the operating circuitry from dust and moisture. An extreme range of permissible operating temperatures made the AN/GRC-106A suitable for use anywhere in the world.

The AN/GRC-106A was designed such that a standard vehicular generating system provided sufficient power (25 amperes) for voice operation. Teletypewriter operation required a higher capacity generating system (100 amperes). The AN/GRC-106A used a half wave doublet antenna in fixed or semi-fixed positions. On a moving vehicle the AN/GRC-106A used a standard 15-foot whip antenna.

AN GRC-106 A Characteristics

Most of the information to prepare this blog comes from “U.S. Army Fact Sheet Radios No. 4, October 1970, AN/GRC-106A.” This fact sheet and other communications-related documents and photographs are available for review at the CECOM Historical Office. The Historical Office is located at Aberdeen Proving Ground. Contact us via our Web-based contact form at http://cecom.army.mil/historian/contactus.php for additional information.

This post was written by Floyd Hertwck.

Posted in From the Archives.

Tagged with , , .

Read Comments


Signal Corps Dirigible No. 1

Over the past few years the CECOM Historical Office has accessioned a large number of items, including photographs, documents, and other items. By using our blog site, we will be introducing some parts of this collection. In this blog article we will discuss some newly discovered era documents related to the original Signal Corps 1, a Dirigible. This Blog article is offered as an update to a blog released on this site 11 July 2011.

The revision is rather exciting, in that we are adding information pertaining to era documents that were generated by the Signal Corps. The documents found are part of a collection of early “Signal Corps Bulletins.” This particular set of bulletins apparently began publication in 1906, and ran through 1912. They in large part are informational or advisory publications as described below.

Signal Corps Bulletins No. 5, ca 1907, is titled “Comprising Signal Corps Specifications on Dirigible Balloons and Heavier-Than-Air Flying Machines.” This bulleting contains “Dirigible Balloons Specification No. 483”, and “Heavier-Than-Air Flying Machines Specification 486.”

Signal Corps Bulletin No. 9, 22 April 1908 is titled “Aeronautics.” This bulletin includes a discussion on dirigibles with photographs of a helicopter and aeroplanes. The bulletin defines aeronautic terms, then applies the terms to various forms of flight, including the dirigible.

Signal Corps Bulletin No. 10, is titled “Dirigible Balloons.” It includes a lecture that was delivered at the Society of Mechanical Engineers in May 1908. The lecture is a technical presentation on dirigible balloons. A second part of this bulletin includes a paper titled “How to construct a Balloon, the Making, Inflating and Sailing of Gas balloons. This paper was prepared by B. Courtright, an Aeronaut.

Signal Corps Bulletin No. 13, “Aeronautical Notes”, ca 1911, is a presentation of additional information that addresses instruments and the purchase of “Dirigible Balloon No. 1.” Also included is a discussion of Signal Corps No. 1, the aeroplane. This bulletin includes photographs and some related diagrams.

These items and other communications-related documents and photographs are available for review at the CECOM Historical Office. The Historical Office is located at Aberdeen Proving Ground. If interested, the reader can also contact the Historical office through our “contact us” Web page at http://cecom.army.mil/historian/contactus.php.

First Signal Corps No. 1 in flight hangar at Fort Myer

First Signal Corps No. 1 in flight hangar at Fort Myer

This post was written by Floyd Hertweck.

Posted in From the Archives.

Tagged with , , , , .

Read Comments


This Week in CECOM History – 19 March 1945

S/SGT Robert L. Lewis, Centralia, IL, directs artillery fire by radio from an observation post in a bomb crater. Smoke rises in the background from shells bursting on German positions in the valley leading to Zweibrucken, Germany. 3rd Infantry Division, U.S. Seventh Army, IV Corps. 19 March 1945. SCR-609.

CE Museum Photo #2021

CE Museum Photo #2021

Posted in From the Archives, This Day In History, This Week in CECOM History.

Tagged with , , , , , .

Read Comments


Happy Birthday, West Point!

On this day in 1802, President Thomas Jefferson signed legislation establishing a permanent military academy at West Point, marking the official birth of West Point – The U.S. Military Academy.

In honor of that birthday, we’ve posted a couple of our many photos showing visits by West Point Cadets to Fort Monmouth.

Photo # EBD526

Photo # EBD526

Photo # EBD0555 - West Point Glee Club Concert, 14 March 1953, Sponsored by the Fort Monmouth Chapter 155, National Sojourners. West Point Glee Club in action under leadership of Lt. Barry H. Drewes.

Photo # EBD0555 – West Point Glee Club Concert, 14 March 1953, Sponsored by the Fort Monmouth Chapter 155, National Sojourners. West Point Glee Club in action under leadership of Lt. Barry H. Drewes.

Posted in From the Archives, History Happenings, Photo Series.

Tagged with , , , , , .

Read Comments


Ready for you Screen Test?

While there are many interesting and intriguing documents in the CECOM Historical Office’s archive, we have chosen one document in particular to discuss here. It is a 1942 report titled “Screen Rooms.” The report was a product of the Coordination Group, V.I. Section, which was a part of the Signal Corps Laboratory.

00000017

This report was generated early in WWII, when the need for reliable radios in vehicles was vital to the War effort. To test vehicular radio noise suppression, it was very important that there be a convenient room that was free of RF (radio frequency) disturbances located in the radio manufacturer’s plants that would allow the testing of radios for vehicle noise in an environment free of noise sources other than the vehicle. The rooms would be used at the manufacturer’s location so as to be near the “production center” of the radio; the manufacturing facility was itself a source of radio noise of varying amplitude and character due to machinery, power stations, and electrical apparatus located within the plant.

The concept of the screen rooms was developed in 1941. The room as conceived would be 40’ long, 20’ wide, and 22’ high, surrounded by walls constructed of two sheets of copper spaced 6” apart. The doors would provide 12’ square opening. The room would also include lighting, ventilation, and testing equipment. The first room was built to design in St. Louis at an automotive plant, and proved the design satisfactory for production testing and to be less costly than standard reference screen rooms in use at the time. When a room was completed, it was necessary to determine its attenuation characteristics which could vary at each location where the screen room was used and to correlate the screen room’s readings with similar tests in noise free locations.

00000016

The report goes on to describe some of the testing that took place, including use of galvanized screen which proved to be similar in performance to copper when installed with “well made joints.” Included in the report are some photographs and inspection information for selected installation locations in Indiana, Michigan, and Missouri. There are also selected drawings and discussions for some of the rooms inspected.

A copy of this report is available from the CECOM Historical Office. The Historical Office is located at Aberdeen Proving Ground. If interested, the reader can also contact the Historical office through our “contact us” Web page at http://cecom.army.mil/historian/contactus.php.

This post was written by Floyd Hertweck

Posted in From the Archives.

Tagged with , , , .

Read Comments