In 1917 American Radio & Research Corporation (Amrad) received an order for thousands of these spark transmitters from the U. S. Army Signal Corps.
The membrane on the right side of the lid allowed the operator to transmit a message with the lid closed.
In 1925 Amrad filed for bankruptcy and the remains of the company was bought out by Crosley Radio Corporation. The Amrad name was used on radios until 1929.
The BC-14A was used by the U.S. Army Signal Corp during World War I.
The BC-14a used a standard crystal detector with a buzzer circuit. The buzzer let the operator know when he had a strong signal coming through the crystal detector.
The receiving circuit used a tapped coil, variable air capacitors and a fixed condenser.
The SCR-68 is one component of the first tube radio system used in U.S. military aircraft. It was first installed in 1917 just months after the U.S. entered WWI. The SCR-68 was built by Western Electric Co for the U.S. Army Signal Corps.
The SCR-68 transmitter / receiver was for short range communications between the squadron leader and the rest of the aircraft in its group.
The tube line-up consisted of three VT-1 tubes, one W-1059 ballast tube and two 205A amplifier tubes.
The SCR-57 is basically an intercom allowing the pilot to switch from radio to talking to his gunner or an observer.
The SCR-57 use six BA-3 batteries as a power source.
Western Electric Company built the SCR-57 for the U.S Army Signal Corps in 1917 as part of the first tube radio communications systems for U.S. military aircraft.
Western Electric Company built the SCR-59 as a receiver for the U.S Army Signal Corps in 1917 as part of the first tube radio communications systems for U.S. military aircraft.
The SCR-59 receiver uses three VT-1 tubes.
Later on a tickler was added to the SCR-59 to improve reception.
Wireless Specialty Company built many of these receivers for the U.S. Navy.
Designed to use a crystal detector or a VT-1 tube.
The IP501 could pick up medium wave and long wave transmissions. A technologically advanced and expensive radio for its time, selling for $348.00 in 1918 or $6527.00 in todays dollars - OUCH!
Designed for use with the IP501 receiver
Originally used VT-Class II or A Moorhead tubes.
While its not too hard to find IP501 receivers, the Triode-B amplifier is an extremely rare find.
The IP503 was designed to be used with the IP500 or IP501 receiver to extend the frequency range to 19,000 meters, at the time the longest wavelength in use.
Designed for Longwave and Very Low Frequency Communications.
The IP503 weighed in at just over 21 lbs.