HS-30-A Headphones

Background

There was some discussion about the HS-30 on the Army Radios Yahoo list server. It was introduced to be a universal headset that could be worn under a helmet and/or gas mask unlike prior headsets that were too bulky. The intention was that you would order not only the HS-30 proper, but also the needed cords, transformer and switching gear and assemble a complete set that would work with your specific radio.

Documentation

Signal Corps Technical Information Letter No. 16, March 1943: III. Accessories for the Versital Headset HS-30 (2 MB file)
The drawing from this document is here (click on image for larger version).

The diagram shows the CD-604 with terminals,
but you need a PL-55 installed on the HS-30 in
order to connect to the CD-604 transformer.

Maintenance

DC resistance is 111 Ohms.
If a 1.5 V Alkaline battery is connected to the leads a very loud clicking will be heard.

Patents

655726 Telephone-receiver, William J Murdock, Aug 14, 1900, 381/393 - method of embedding the entire magnetic mechanism in a single molding, long pole
1273351 Telephone-receiver, Halsey A Frederick, Jul 23, 1918, 381/412 - early WE, Signal Corps Type P-11 - common headphone arrangement, horseshoe magnet
1153593 Telephone-receiver, Nathaniel Baldwin, Sep 14, 1915, 381/418 - long pole, horseshoe magnet
1452334 Telephone receiver, Chaeles Town Send baisley, Electrical Supply Co., Apr 17, 1923, 381/412 - horseshoe magnet
1536486 Telephone diaphragm, Hermann Fischer, May 5, 1925, 381/429, 181/137 - woo woo? slots in diaphragm to improve response? horseshoe magnet
1551143 Telephone receiver, Halsey A Frederick, Aug 25, 1925, 381/414 - horseshoe magnet
1583416 Vibration-responsive apparatus, Moore Charles R, Western Electric Co, May 4, 1926, 181/175, 181/166, 181/158 - damped with multiple sheets of thin waxed paper

2501107 Headband, Volkmann John, Sec of War, App: 1944-05-27, W.W.II, Pub: 1950-03-21, -

2584402 Acoustic coupler for earphones, Volkmann John, OSRD (Wiki), App: 1944-06-05, W.W.II, Pub: 1952-02-05, -

2647956 Flexible microphone suspension, Edwin B Newman, Volkmann John, OSRD (Wiki), App:1945-06-28, TOP SECRET, Pub: 1953-08-04, - Lip Mike (Wiki)

Freed-Eismann Radio Speaker FE-50
Phones
Telephone Patents
Military Audio Accessories
Audio Connectors & Cloning - Fill - Retransmission
U-229 Audio Accessories
U-229 Pin Out

Links

Fair Radio Sales

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[an error occurred while processing this directive] page created 7 Jan 2011.

		2501107 Headband, Volkmann John, Sec of War, App: 1944-05-27, W.W.II, Pub: 1950-03-21, -
		2584402 Acoustic coupler for earphones, Volkmann John, OSRD (Wiki), App: 1944-06-05, W.W.II, Pub: 1952-02-05, -
		2647956 Flexible microphone suspension, Edwin B Newman, Volkmann John, OSRD (Wiki), App:1945-06-28, TOP SECRET, Pub: 1953-08-04, - Lip Mike (Wiki)