Glass cover in place

Close up of Coherer/Decoherer Assembly

Glass cover removed

Klickknick Coherer Receiver
c. 1900
 

Early "Pistol" Coherer
(Italy)

This unusual apparatus is a coherer connected to an electromagnet. When the coherer detects a radio pulse, the magnet pulls the trigger of a cap gun, producing a loud report.  This device is believed to be modeled after Marconi's experiments where a gun was used to signal successful reception of a signal transmitted from out of view.

Recieving Set - Detector and Tuning Inductance
International Telegraph Construction Co.
c. 1906

Detector features an electrolytic detector utilizing platinum wire in a 20% sulfuric acid solution. Paper tag reads: "SN 1702 from USS Ozark."
The large lever is an antenna switch, used to disconnect the receiver from the antenna when the transitter (not shown) is operating. To my knowlege, this is the only example of this receiver that has survived.

Photo of the International Telegraph Construction Co. receiving set, designed by the famous wireless engineer Harry Shoemaker.  This image is from the book "Manual of Wireless Telegraphy for Naval Electricians" by S.S. Robison (1913).

Wireless Specialty Apparatus Co.
IP-76 Receiver
c. 1910

A fine example - only a few of these early receivers have survived.

 2-coil Syntonizer
The Radio Company (De Forest)
c. 1906

Also known as the United Wireless Type A tuner, this very rare device was designed by the great wireless engineer Harry Shoemaker.

Type D Tuner
United Wireless Telegraph Co.
c. 1910

Type E Tuner
United Wireless Telegraph Co.
c. 1912

Wireless Specialty Apparatus Co.
SE-1220 Receiver
c. 1918

The SE-1220 is the military version of the IP-500 radio receiver.

Wireless Specialty Apparatus Co.
IP-503 Long Wave Loading Unit
c. 1920

Designed for use with the IP 500 and IP 501 radio receivers. When placed on top of either receiver, the binding posts on the IP503 line up with the loading coil terminals on the receivers. Short jumper straps were used to link them together. Use of these coils extended the frequency range of the receivers to 19,000 meters, the longest wavelength of commercial stations in use.

National Electrical Supply Company
CN-240
c. 1917

National Electrical Supply Company
SE-143A
c. 1918

This receiver is the NESCO eqivalent of the Wireless Specialty IP-500, both were essential pieces of wartime of communications gear.

Westinghouse SCR 70
1917
Rare early Signal Corp communication receiver designed by Frank Conrad. Conrad is considered by many to be the father of commercial radio broadcasting.

International Radio & Telegraph Co.
Vacuum Tube Tuner

Radio Apparatus Co.
Long Wave Tuner
c. 1920