Sound Powered Elements for Crystal Sets
"Balanced Armature" Elements used for crystal radio sets

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RCA    US Navy "Deck Talkers" (headset)
(Radio Corporation of America)
 

Ear elements (from headset MI-2045-E (older model) "Big Can")

   Rear View                Front View            Side View

No numbers

Specs.
85 ohms DC resistance
aprox. 600 ohms impedance
2 1/4" dia. x 1 5/16" thick

Ear element (from headset MI-2454-B (newer model) "Small Cans")

          Front View                                   Rear View
 

No numbers

Specs.
205 ohms DC resistance
1 7/16" dia. x 5/8" thick
 

Mic elements  (from headset MI-2045-E (older model) "Big Can")
 

   Rear view                 Front View             Side View

No numbers

Specs.
8.6 ohms DC resistance
unknown  ohms impedance (working)
2 1/4" dia. x 1 3/8" thick

RCA   Hand Set (US)
(Radio Corporation of America)

Ear element

  Front View

No number marks
Specs.
87 ohms DC resistance
unknown  ohms impedance (working)
2 1/4" dia. x 1 3/8" thick
 

Mic element

 Front  View

No number marks
Specs.
142 ohms DC resistance
unknown  ohms impedance (working)
2 1/4" dia. x 1 3/8" thick
 

Rear of both ear and mic elements
 

Side of both ear and mic elements

Ear and Mic element are the same

  Front View                 Rear View           Side View

MI-22151-A & MI-22151-E
Sub numbers 2A4

Specs.
73.1 ohms DC resistance
300 ohms at 1 kHz impedance
2 1/8" dia. x 1"

Ear and Mic elements

   Rear view                 Front View          Side View

UA1611-2 Mic. element
Sub numbers on elements
1100,4052,P030 4-79

UA1611-1 Ear element
Sub numbers on elements
1100

Specs for both elements
4.4 ohms DC Resistance
unknown ohms impedance (working on data)
2 1/4" dia. x 7/8" thick

Note: Most of the Stromberg Carlson Handsets use USI elements inside and are marked with USI on back

Ear and Mic elements for H203/U
Both elements are "domed" in the front

  Rear view                 Front View

UA1614-1
Sub numbers P030 11-76

Specs.
62.3 - 62.7 ohms DC resistance
1100 ohms to 1900 ohms AC impedance @1 kHz.
2 1/8" dia. x 15/16" thick
 
 

Ear element for A257

   Rear view                 Front View

UA1614-3  1248-A (on front of all units)
Sub numbers 11-75, P030

Specs.
60.2 - 64.6 ohms DC resistance (60.2, 64.6, 64.5)
700 ohms AC impedance @1 kHz.
2 1/8" dia. x 15/16" thick
 

Mic element for A257

  Rear view                 Front View

UA1614-4,  UA1614-1
Sub numbers 11-76, P030, P030 11-76

Specs.
92.1 ohms DC resistance
885 ohms AC impedance @1 kHz.
2 1/8" dia. x 15/16" thick

U S Instrument (USI) "Deck Talkers" (headset)
and
U S Instrument (USI) Handset
Both handset and headset use the same elements

Ear Element

  Rear View                Front View

UA1614-3  (A560, A577, A333 units), 1248-A (on front of all units)
Sub numbers D1985, 8-50

Specs.
60.2 - 64.6 ohms DC resistance (60.2, 64.6, 64.5)
unknown  ohms impedance (working)
2 1/8" dia. x 15/16" thick
 

Mic Element

  Rear View                 Front View

UA1614-4 (A560 unit), UA1614-15 (A577 unit), 1247-A (on front of all units)
Sub numbers F1985, , 2085, 1165

Specs.
63.5 - 90.4  ohms DC resistance (63.5, 87.2, 90.4)
unknown  ohms impedance (working)
2 1/8" dia. x 1 1/8"

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   Front View                        Rear view                     Side View

Specs.
27.6 ohms DC resistance
280 ohms impedance @ 1 khz.
2" dia. x 1 1/8" thick

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Automatic Electric Company  "Deck Talkers" (headset)

Ear Element

   Front View                   Rear view               Side View

GD-51002-B
no sub numbers

Specs.
74 ohms DC resistance
900 ohms impedance
2 3/4" dia. x 1 1/8" thick

Mic Element

   Front View                         Rear view               Side View

GD-38330-B
sub number  RS

Specs.
4.2 ohms DC resistance (very close to Stromberg Carlsons)
45 ohms impedance
2 1/8" dia. x 1 1/8" thick

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  Front View                 Rear view

Photos courtesy of Steve McDonald

GH-69722-1
no sub numbers
R17T23 on handset on outside

Specs.
77 ohms DC resistance
900 ohms impedance
2 1/8" dia. x 1 1/8" thick
 

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Dynalec Corporation Headset "Deck Talkers" (headset)

Ear and Mic elements

   Rear view                 Front View          Side View

UA1611-2 Mic. element
Sub numbers on elements

UA1611-1 Ear element
Sub numbers on elements

Specs for both elements
4.4 ohms DC Resistance
unknown ohms impedance (working on data)
2 1/4" dia. x 7/8" thick

You must have Adobe Reader to read the following:
Specification's for H200U Headset (Deck Talkers Style) (407k) Click here
Element Specifications (113k) Click here
 

Dynalec Corporation Handset

Ear and Mic elements

Rear view
 

Handset stripped down
 

You must have Adobe Reader to read the following:
Specifications for H203U Handset (329k) Click here

Thanks to Steve Bringhurst for finding the above photos!

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Telephonics Company

Ear and mic elements

   Rear view                 Front View            Side View

140704
sub numbers 32,248D066

Specs.
45 ohms DC resistance
unknown  ohms impedance (working)
2 1/4" dia. x 7/8" thick

Note: These elements were probably made by Stromberg Carlson (before 1960) or Dynalec (after 1960)

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TA-1/PT

Ear element

 Front View                 Rear View         Side View

No numbers

Specs.
65 ohms DC resistance
unknown  ohms impedance (working)
2 1/32" dia. x 11/16" thick

Mic element

 Front View                Rear View         Side View

No numbers

Specs.
62 ohms DC resistance
unknown  ohms impedance (working)
2 1/32" dia. x 11/16" thick

Note: These units were made by many different makers, most are not in business anymore.
All use the exact elements leading me to believe that one maker may have made all the elements.

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Western Electric Company "Deck Talkers" (headset)

U S Navy "Deck Talker" type, D173014 (on ear pieces)
Ear element

  Front View                Rear View              Side View

D-173012
Sub numbers 8-46, MA

Specs.
10.2 ohms DC resistance
unknown  ohms impedance (working)
1 13/16" dia. x  1 1/16" thick
 

Mic element ("Transmitter Unit")

    Front View                        Rear View                  Side View

D-173464
Sub numbers (none)

Specs.
72 ohms DC resistance
unknown  ohms impedance (working)
1 13/16" dia. x  1 1/16" thick
 
 

Type D173463 (on earphone pads) Deck Talkers
Ear element

  Front View                Rear View

No numbers on units

Specs.
303.0 ohms DC resistance
unknown  ohms impedance (working)
No dim. (part of the housing and can not be separated)
 

Western Electric Company Handset

Ear element

  Front View                Rear View              Side View

D-173012 (for both regular and submarine handsets)
Sub numbers 8-46, MA

Specs.
10.2 ohms DC resistance
unknown  ohms impedance (working)
1 13/16" dia. x  1 1/16" thick

Mic element

 Front View                Rear View              Side View

D-173011 (for regular handset) , D173016 (for submarine handset only)
Sub numbers 5-48, AA

Specs.
73.8 ohms DC resistance
unknown  ohms impedance (working)
2 3/16" dia. x  1 1/8" thick

Western Electric Company Headset (Vintage, not balanced armature)

   Rear View                Front View

Non "sound powered" element from headphones
Will function like sound powered units (from WE headset and phone unit)

The Wheeler Insulated Wire Company Inc.

Ear and Mic elements

Front View                 Rear View            Side View

No number marks

Specs.
93 ohms DC resistance
unknown  ohms impedance (working)
2" dia. x  3/4" thick

TMC "Decktalkers" (England)

Ear and Mic element are the same

These element photos are RCA (Canada), but are the same except marked TMC. See RCA   Hand Set (Canada)
They are basically the same.

  Front View                 Rear View           Side View
See RCA   Hand Set (Canada)
They are basically the same.
 

TMC "Handset" (Canada) TMC-51

The elements look the same (almost) as TMC "Decktalkers" and RCA handset (Canada) except
they have a covering (clear) over the diaphragm on the front. I believe they are made to government specs.
and is why they look so much like the RCA (Canada) elements. This is done by the US government with the
TA-1/PT handsets so parts are interchangeable.

  Front View                Rear View                Side View

AP18221
sub numbers none

Specs.
91.5 ohms DC resistance
325 ohms impedance (AC)
2 1/8" dia. x  1" thick
 

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Sound Powered Communications Corp. Handset

Ear and mic elements

TRU-105 (for SPT-500 SP units)
Sub numbers (none)

Specs.
55 ohms DC resistance
300 - 400 ohms impedance
1 15/16" dia. x  7/8" thick
 

Ear and mic elements

  Front View                 Rear View         Side View

TRU-103 (for SPT-125 S units)
sub numbers B880, "Transducer"

Specs.
99.8 ohms DC resistance
unknown ohms impedance
2" dia. x  7/8" thick

Ear element only

  Front View               Rear View                  Side View                     Side View
 

Specs.
13.5 ohms DC resistance
150 ohms impedance @ 1 kHz.
1 11/16" dia. x  11/16" thick

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