The sound from the speaker's voice powers the phone
so no external power is needed.
Sound Powered Element
United States Instrument Corp. 1247A G4 Sound Powered
Element. Measures 60 Ohms and makes sound when tested
using the Fluke DMM DIODE test
function (i.e. 1 mA)
Fig 1 Element sitting in cup (no cover)
|
Fig 2 After lifting the element out of
the cup.
U.S. Instrument Corp.
UA1614-11
U.S. Patent
No. 2245511
 |
Fig 3
After removing 2 screws to open back cover
 |
 |
|
2060607
Telephone, Joseph
A Briggs, RCA,
1936-11-10, 381/411; 381/418 -
electromagnetic type that is rugged and capable of
withstanding severe shocks and blows
The Baldwin design was much harder to make and not as
rugged as this one. |
|
|
2100500
Telephone unit, Albert
E Woodruff, Sengebusch
Hans, Associated
Electric Lab, 1937-11-30, -
Albert Woodruff worked for Associated Electric Lab
from 1934 till 1941 (Start of W.W II?)
then he started working for Automatic Electric (Wiki:
AE)
and his last patent with AE was 1953.
|
|
|
2241106
Sound translating device, Albert
E Woodruff, Associated
Electric Lab,1941-05-06, 335/231; 335/279; 335/281;
335/276 -
|
|
|
2241107
Sound translating device, Albert
E Woodruff, Associated
Electric Lab,1941-05-06, 381/418; 381/419 - horseshoe
magnet
|
 |
 |
2245511 Telephone instrument, Jr
Arthur Turnbull, Herbert
R Warnke, United
States Instrument Corp, filed: 1937-12-04, Pub:
1941-06-10, 381/418 -
|
 |
|
2400281 Electromechanical signal
translating apparatus, Leslie
J Anderson, RCA,
filed: 1940-10-31, Pub: 1946-05-14, 381/346; 181/166;
381/417; |
Remco
Toy Sound Powered Telephone
This pair of toy sound powered phones was very reasonable
on eBay. The reason is that one of them has a very
poor electrical connection and the other about 11 Ohms, but
steady.
You can see from Fig 2 below that there's only one sound
power element and it serves as both the microphone and
speaker. The problem was they uses a pressure
connection between the external terminals and a pair of
spring contacts.
After using a pencil eraser to clean the terminals and
bending one of the springs out a little the phone halves
were mated and the Ohm meter read a solid 11.7 Ohms. A
few drops of acrylic cement (maybe) will complete the
repair.
Control Instrument Co patent 2109761 uses the same method of using
a single transducer and a speaking tube so it can be used as
both the transmitter and receiver.
Fig 1
|
Fig 2
 |
Fig 3
 |
|
|
|
US2536179
Magnetic sound-powered telephonic unit, Isaac
Heller, Remco
Ind, Jan 2, 1951, 381/161,
381/418,
381/396
The bottom two illustrations are of how they make a
long bar magnet and break it into small pieces for
use in the element.
|
|
2692918 Magnetic sound powered
telephone, Samuel
I Berger, 1954-10-26, 381/418 -
Put this patent under the Toy phone because Berger has
other patents for sheet metal toys.
Calls:
2245511 see above
2400281 see above
2454425
Magnetic translating device, Benjamin
B Bauer, Shure
Inc, filed: 1943-12-23, Pub: 1948-11-23, 335/231; 335/281; 310/25; 369/148
- dynamic mike
2523775 see below
2536179 see above
2582942 see below
|
Wheeler
Insulated Wire Handset
AKA: Sound Powered Communications Corp.
SPT-125 with 1/4" Phone Plug
Fig 1 New Old Stock (NOS) SPT-125
|
Fig 2
 |
Fig 3 Notice the same element for both
talking and listening.
 |
Wheeler Insulated Wire Co. adapted that name in 1922 since
their main product was insulated magnet wire. During the
second world war they made the ‘Marine
‘Raider’ Receiver. (let me know what it is).
Only after the war did they start making sound powered phones.
(Connecticut
Mills).
Electronics magazine, Dec. 1949 - pg 179 Wheeler Insulated
Wire Co. ad for transformers and other products that are
mostly magnet wire, but no sound powered phones.
Fig 1
|
|
|
2492056
Batteryless ringing device, William J
Muldoon, Wheeler Insulated Wire, 1949-12-20, 379/373.01; 340/328; 310/25;
381/162; 381/418 - dial plucks reed which is
coupled to similar reed in Rx set. Vibrating
reed taps bell. Intended for toy phones as well
as short range general applications
|
|
2523775
Electromagnetic transducer, William
J Muldoon, Wheeler Insulated Wire, 1950-09-26, 381/418; 310/25 - |
|
2523769
Calling unit, John
H Maloney, Randall
B Baker, Wheeler Insulated Wire, 1950-09-26, 310/25; 340/333- causes
loud noise in receiver units rather than separate
sound maker
|
|
2533136
Vibratory reed signaling device, William
J Muldoon, Wheeler Insulated Wire, 1950-12-05, 340/384.73; 310/25; 116/167;
379/167.01; 335/93- more powerful ringing
than patent 2492056
|
|
2582942
Electroacoustical transducer, Randall
B Baker, Wheeler
Insulated Wire, 1952-01-22, 310/25 - same
application as 2523775. |
|
2607857
Telephone handset, Randall
B Baker, Wheeler
Insulated Wire, 1952-08-19, 379/433.01; 446/142 - Tx and
Rx units plug in (no screws), toothed wheel for
2523769 signaling
|
|
2634378
Vibratory reed signaling device, William
J Muldoon, Wheeler Insulated Wire, 1953-04-07, 310/29; 340/6.13; 335/252;
335/230; 340/333 - even more powerful,
includes bell
|
|
2808461
Handset, Aldrich
R Thomas, Wheeler Insulated Wire, 1957-10-01, 379/422; 379/395; 379/433.06;
379/433.01- includes a PNP transistor
amplifier in the Tx cavity or can work as sound
powered w/PB switch.
|
Control
Instrument Co. Handset
Fig 1 Type L
Serial No. 2267
N.D. Control No. d1515, N.D. Insp.
Intermittent connection.
|
Fig 2 inside both elements look the
same.
|
 |
2109761
Telephonic device, Herbert
R Warnke, Control
Instrument Co, 1938-03-01, -
The Remco
toy uses the same method of using a single
transducer and a speaking tube so it can be used as
both the transmitter and receiver.
|
|
2115795
Magnetic unit, Herbert
R Warnke, Control
Instrument Co,1938-05-03, - for high power
loudspeaker?
|
|
2143097
Telephonic unit, Herbert
R Warnke, Control
Instrument Co,1939-01-10, -
"...capable of Operating as a receiving unit or as a
transmitting unit...high efficiency." |
|
2163161
Magnetic unit, Leslie
H Wadsworth, Control
Instrument Co, 1939-06-20, - "one-piece magnet casting"
- sound powered element (either Tx or Rx).
|
|
2215782
Telephonic unit, Grenville
B Ellis, Control
Instrument Co, 1940-09-24, - Diminishes
"blasting" like happens with gun fire nearby.
For more patents by G.B. Ellis see Radiosonde
Batteries.
|
|
2358529
Telephone system, William
J Muldoon, Harold
T Stenhammer, Control
Instrument Co, 1944-09-19, - much simplified
based on stepping switches.
|
|
2372801
Selector switch, Harold
T Stenhammer, Control
Instrument Co, 1945-04-03, -
|
|
D140289
Casing for telephone units, William
J. Muldoon, Filed: 1944-08-21, Pub: 1945-02-06,
- wedge shape unit
|
|
2380560
Permanent magnet, Urquhart
Noel, Control
Instrument Co, Filed: 1942-06-11, W.W.II, Pub:
1945-07-31, - "...a protective coating is applied
thereto to prevent corrosion and chipping under shock.
.." "It is an object of the invention to completely
cover a permanent magnet with a protective coating,
while causing no impairment of its mag netic
performance." |
|
2381673
Electromagnetic device, Lehde
Henry, Control
Instrument Co, Filed: 1942-04-06 W.W.II, Pub:
1945-08-07, -sound powered element, either Tx or Rx.
very rugged, easily assembled,
|
|
2389695
Impulse sender, Harold
T Stenhammer, Control
Instrument Co, 1945-11-27, - quiets down the
clicking noise of a phone dial
|
|
2432424
Electromagnetic sound translating device, John
J Hyland, William
J Muldoon, Control
Instrument Co, 1947-12-09, 381/418; 310/25 - |
|
2523775
Electromagnetic transducer, William J
Muldoon, Weeler
Insulated Wire, 1950-09-26, -
|
Chest Set
This set has a strong similarity to the Dynalec UA1814-1
(702020-110) NSN: 5975-01-27, DTID: 3211A0128BH21 but this
set has the chest mount microphone support and headphone
headbands.
In the movie Submarine: Steel Boats - Iron Men (IMDB)
about life on the USS Hyman G. Rickover (Wiki)
what appear to be sound powered chest sets are used in many
places.
Fig 1 United States Instrument Corp.
 |
|
Dynalec H-200/U Sound Powered
Chest Set
|
Type H-200/U
Sound Powered
Headset-Chestset
NSN: 5965-00-900-6401
Naval Sea Systems Command
Dynalec Corp p/n: 702019-375
Contr: DLA900-90-C-1582
Serial No. (blank)
Insp. (blank)
|
Patents
2149628
220566?
2205906
Sound translating device supporting assembly, Herbert
F Obergfell, Associated
Electric Labs,
H-203/U Handset
This is a handset with Push-To-Talk button. With the
button up the resistance between the 2 leads shows open,
when the button is pressed the resistance is about 32
Ohms. In DMM Diode Test mode when the button is
pressed and the leads are brushed against the phone
terminals you can hear scratching sounds from both the mike
and earphone on the handset.
Switch Plate marked:
Sound Powered Handset Type H-203/U
Stock No. 1N5965-247-0727
Navy Dept. Bu. Ships
Stromberg-Carlson
Contract No. N001 26-69-G-2303
Serial No. (blank) Insp. (blank) |
Receiver Marked:
1247-A
Alcoa 2
|
Transmitter Marked:
1247-A
Alcoa 1
|
There is a small difference in the elements used for the
microphone and speaker, but the fundamental part numbers
seem to be the same.
Fig 1 The screw on caps are made of
brass, not plastic.
|
Fig 2
15 MF
200 VDC
|
|
1247A
Alcoa 2
UA1614-1
U.S. Patent
No. 2245511
9/67
|
1247-A
Alcoa 1
UA1614-1
U.S. Patent
No. 2245511
10/69
|
|
|
|
TP-3 Sound Powered Telephone Set
This is a telephone set, meaning that it has ringer
capability in addition to the sound powered aspect. It
has the same functionality as the TA-1
Sound powered field phone set below.
This is a derivative of the EE-8 Field
Telephone and uses the same outer case (either leather
or canvas) and many other parts interchange. The key
difference is that the handset makes use of sound powered
elements and so it does not need a battery. The sound
power elements are the same as in
the H-203 handset.
There are a couple of blocking capacitors included in this
set, one to keep DC out of the sound powered handset and
another to keep DC away from the ringer coils/core.
When used with a common battery switchboard an off hook
signal to the operator is possible by shorting the L1 and L2
terminals in an alternating pattern of 1 second short 1
second open.
Manuals
Instruction Book for Telephone TP-3-T1
December 5, 1938
Reprint July 15, 1940
TM11-2043
TO 16-40T-P3-5
Telephone
TP-3
War Department - 30 August 1944
Technical Data
The handsets measure 36 and 40 Ohms. About the same
as the H-203 above which makes sense since they both use the
same elements.
Fig 1
|
Fig 2 the right side plate is bent.
 |
From Instruction Book.
This is the same mechanism
as 1767546 Fig 2 (below).
|
Fig 3
 |
TA-1 Field Phones
Note the ear piece is much thinner on the TA-1 when
compared to the The chest set, H-203 or TP-3 above.
That's so that the ear piece can be placed under a helmet.
Fig 1 with carry case
|
Fig 2
|
Sound powered field phones with generator driven buzzer, so
no batteries or external power needed. On separate web
pages TA-1.
Earphone element: SM-D-189373
Microphone element: TA-Z21/PT
Baldwin
Driver + Horn
This is a three part horn.
The cast iron base holds the driver.
The cast iron neck connects the base to the big horn.
The big horn is made of Bakalite with a sheet metal ring for
the connection to the neck
Fig 1
|
Fig 2 Note bottom plate of base is
friction fit with felt trapped between the two.
 |
Fig 3 Using the DMM Diode test function
produces a loud scratching noise.
 |
Fig 4 Nathaniel Baldwin Incorporated
Salt Lake City, Utah
Patented
May 10, 1910 Sept 14 1915
Those are different than the patents listed on the driver above.
They are 957403 and 1153593
 |
Fig 5
 |
Fig 6 "Standard Loud Speaker"
 |
Baldwin Headphones
Label on back of phones:
Manufactured and Sold by the Baldwin Radio Co. Salt Lake
City, Utah, under Nathanel Baldwin's Pat May 18, 1910 (see 957403 above), Sept 14, 1915 (see 1153593
above), Type "C".
Note that patent 1604251 (See above)
is not referenced so these were made after 1915 and before
1924.
Fig 1
|
Fig 1cu Close Up of Label
|
Fig 2 Pat Feb 2, 1915 (see 1127161 above)
 |
Fig 3 Inside
 |
Fig 4 Inside
 |
|
Dictograph
Western Electric No. 555 Receiver
This was the first loudspeaker to be used for talking
movies (Wiki).
It consisted of the WE No. 555 moving coil driver coupled
with a huge horn to make enough sound for to fill a movie
theater.
1707544
Electrodynamic device, Albert L Thuras,
Western Electric, Filed: 1926-08-04, Pub: 1929-04-02 -
Dynamic moving coil speaker driver - WE No. 555
1729806
Electrodynamic device, Albert L Thuras,
Western Electric, Filed:1928-04-26, Pub: 1929-10-01 -
increase the efiiciency of electrodynamic devices
1812389
Acoustic device, Edward C Wente,
Western Electric, Filed: 1925-04-01, Pub: 1931-06-30 -
probably the No. 555 driver "Receiver"
Western Electric No. 509w Receiver
Patent date July 23, 1918
1273351
Telephone-receiver, Halsey
A Frederick, WE,
1918-07-23, - maximum efficiency (for the time), uses
Silicon steel coil core.
Peerless Speaker (Lektophone)
This speaker was made under the
Lektophone Patents as were many early speakers while the
patents were in force.
The label spells this out.
Peerless
Licensed Under
Lektophone Patents
No. 1271527 - No. 1271529
No. 1271528 - Other Patents Pend.
Manufactured by United Radio
Corp. Rochester, N.Y. U.S.A. |
This speaker was purchased and
it's located on the Sound Powered Telephone web page
because the central axis of the coil is a right angles to
the central axis of the speaker cone, i.e. an efficient
structure.
The speaker measures 1.34 k
Ohms. There is a low pass filter made up of two
capacitors and an iron core inductor between the input
wires and the speaker proper. When you look into the
front with a flashlight you can see a second cone.
That's to say there are two speaker cones with different
cone angles.
Photos
Fig 1 Front
|
Fig 2 Back
 |
Fig 3 Bottom
 |
Fig 4
 |
Fig 5
 |
Fig 6 Coil at top of horseshoe magnet
has it's axis up and down.
 |
Patents
----------------------------
Listed on Label ----------------------
1271527
Sound-regenerating machine, Marcus
C Hopkins, Lektophone
Corp, Jul 2, 1918, 369/80,
369/158
- This is a
flat record player (not Edison cylinder, Wiki)
and instead of using a horn speaker (Wiki)
it uses a large diameter cone that has a rod driving the
center point.
1271528
Sound-regenerating machine, Marcus
C Hopkins, Lektophone
Corp, Jul 2, 1918, 369/158,
369/170
- very similar to the ...527 patent.
1271529
Acoustic device, Marcus
C Hopkins, Lektophone
Corp, Jul 2, 1918, 181/164,
181/173,
181/171,
369/155,
381/432
-
-------------------------- Other Patents Pend.
----------------------
1389632
Acoustic diaphragm, Davis
William H, Joss
Fredrick E, Lektophone
Corp, Sep 6, 1921, 181/171
- Just the
cone part of a speaker
1829355
Acoustic diaphragm, Houghton
Vernon T, Lektophone
Corp, Oct 27, 1931, 181/173
- about folding the cone outer diameter
surface to add compliance. Modern speaker cones have
"ripples" to to that.
1855168
Loud
speaker, Farrand
Clair L, Lektophone
Corp, Apr 19, 1932, 381/418,
381/432,
181/172
- can
be used as either Microphone or speaker. "'The principal object of this
invention is to provide a loudspeaker of the above
described general type in which the flexible support for
the diaphragm is supplemented by a special flexible
support for the armature, which will permit the armature
to move freely in an axial direction but will hold the
armature, or assist the flexible support for the cone in
holding it, in the proper aligned position in the air gap.
" Coil axis is concentric with cone axis so not the
high efficiency Sound Powered Telephone design.
Lektophone Corporation v. The Rola Company, 282 U.S. 168
(1930) (Supreme.justia,
FindLaw)
"There is not to be found in the prior art a
sounding board such as Hopkins designed and had patented
as his invention, and it is not enough to defeat his
patent to say that the elements of his claims are already
found in the prior art in isolation or in other
combinations."
963362
Apparatus for recording or
reproducing sounds, Thomas
A Edison, Jul 5, 1910, 369/165;
181/162; 181/173; 369/168 -flat pleated disk, not a cone
986477
Acoustical instrument, Louis
Lumiere, Mar 14, 1911, 29/896.23;
369/160 - pleated cone
Tivoli Audio Model One Radio
Tivoli Audio (Wiki)
- "The Company was founded in Massachusetts in 2000
by legendary audio engineer Henry Kloss and entrepreneur Tom
DeVesto, who noticed a gap in the consumer audio market for
high-quality, well designed and affordable audio products.
Their first product was the Model One, a simple to use
mid-century modern designed table top radio with a
high-performance tuner, receiving FM radio in congested urban
locations, while maintaining the ability to pick out distant
or low power stations."
While watching a number of streaming TV series set in
Scandinavian countries a common small table radio shows up.
I searched for it expecting it to come from Sweden or
Denmark. But it was designed in the U.S.A. and some
legendary audio people were involved.
While the design was what attracted me in the first place
there are other features that make this even more
attractive. The Auxiliary input senses when the 1/8"
stereo plug is inserted and turns off the radio audio
automatically. This allows the box to be used as an
amplified speaker. See: Music Speakers. In
addition there is an option for "12 Volt DC" power, which
has two advantages, first: allows radio to be used in an
emergency powered from batteries or a cigarette lighter
adapter and second: by using a small battery as a portable
music speaker.
It came with only the AC line cord, so I purchased an FM
antenna with a Type-F connector on eBay as well as some
stick-on feet since the factory feet had fallen off.
While researching this model I found a number of fix-it
YouTube videos about replacing the tuning capacitor.
Rather than do that I looked for a radio that had a
manufacturing date sticker hoping that meant the radio was
new enough not to need that repair. So far that's the
case.
Photos
Fig 1
|
Fig 2 The black circle is the end
of a tube
that's part of the bass reflex loading design.
 |
Fig 3 Connectors
Aux In: 1/8" stereo
DC In: 5.5mm x
Ant: The eBay "75 Ohm
Indoor FM Dipole Antenna Radio Stereo Signal
Receiver Amplifier Aerial" is defective.
Instead of a wire center conductor it has a tube so
will not fit. I have a message to the seller:
lepo-beauty. More after
I hear back.
This is a "PAL" connector for Eurpoe, not the wire
type for the US.
|
Bass Reflex Speaker Design (Audio
Judgement)
CCRadio2
This radio is made at C Crane located a few hours
drive North of me. It has bands: FM, AM, 2 meter Ham, WX
& Aux audio in. It does not have shortwave.
Runs on AC line or internal 6 D cell batteries. This is
much more convenient than using an external battery pack with
the Tivoli above. After a month or so the "D" batteries
have gone dead. Not sure if that's because they started
out low or if the radio consumes a lot of power when
"off". You should probably store batteries out of the
radio.
When the batteries die so do all the presets.
Not so great as an emergency radio because there will be no
preset frequencies. You need a hard copy so you can load
the frequencies after you install fresh batteries.
There are 5 preset frequencies for each band so a total of
20. To select a preset you need to first choose the band
then press the desired preset.
There have been a number of CCRadios with different features
over the years. Got this one used from eBay. It's
the CCRadio2 not the CCRadio2E that has better sound quality.
Preset frequencies:
1. (2 meters) 147.39
Press and hold a control for a few seconds to get the
(secondary function).
Main Tuning knob (Squelch)
Unlike the Tivoli
above, this radio does not have an external FM antenna
input.
Power
AC mains or internal 4 internal D cell batteries.
Mode
|
VDC
|
Function
|
Current
ma
|
Off
|
6.0
|
BL Off
|
0.001
|
Off
|
6.0
|
BL Very Dim
|
0.000
|
Off
|
6.0
|
BL Bright
|
0.017
|
On
|
6.0
|
Loud
|
0.3
|
| Dead |
3.9 |
-- |
-- |
The Energizer L95 (datasheet.pdf)
should last a very long time IF the Back Light (BL) is off
or very dim AND the WX monitor function is turned off.
Note: When the battery goes dead you loose all preset
frequencies.
Fig 1 Front
|
Fig 4 Close-up of top Push Button PCB.
Right Angle Momentary Tactile Push Button Switch
maybe 6x6x5mm size?
The buttons are hinged and
have a post that presses on the switch.
There are Surface Mount resistors, maybe the
resistance
indicates which button pressed, or it's a matrix?
|
Fig 2 Rear
 |
|
Fig 3 Inside - Looks like was in dusty
environment.
 |
Remove 6 screws (all have an arrow).
Top: Ferrite Antenna
8 Push button PCB
Left: RF & AF PCB..
Left hidden: Front panel PCB
Middle: 4 Ohm 6 Watt Speaker
AC to 6VDC power supply at lower right corner.
|
Acoustic Research Speakers
Acoustic Research (Wiki) - "Acoustic Research, Inc. (“AR”)
was founded in 1952[1] and incorporated on August
10, 1954, by audio pioneer, writer, inventor,
researcher and audio-electronics teacher Edgar Villchur and
his student, Henry Kloss."
When I built a Heathkit Hi-Fi system the speakers were
copies of the AR-1.
YouTube: DeVORE FIDELITY: John
DeVore goes on a rant about the High End Audio lie that
inspired him to start his company - This is about
speaker sensitivity:
A7 Voice of
the Theater Speakers
Altec Lansing (Wiki),
JBL (Wiki)
I got these as part of a Hi-Fi system that was built into a
house. There were alcoves on either side of the
fireplace where these sat. A speaker cloth grill
covered them and the wiring was routed inside the house to
the electronics which ended up being McIntosh. See Home Theater VOT for
more.
The sensitivity of the A7 VOT is 97 dB. (sound level 1
meter in front of speaker with 1 Watt drive.) This
goes directly to dynamic range since the maximum power is
limited to the 200 Watt speaker rating or the amplifier
rating. When music is played loud you're at the max
rating for the loud passages and the speaker sensitivity for
the quieter passages.
The heart of the speaker is the horn (Wiki).
A comment by James Wilkes related by my comment on the
YouTube:
YouTube: DeVORE FIDELITY: John DeVore goes on a
rant about the High End Audio lie that inspired him to start
his company - This is about speaker sensitivity:
Looks like they have a
515B LF driver, Altec Lansing specs for it say 98dB at 4'
with 1W pink noise 500-1000 Hz, which is probably the safe
figure -
500-3000 Hz yields 102 dB, but that's because the driver is
rather peaky above 1000 Hz. SPL varies with distance per
square law,
so a reading from 1m should be nearly 2 dB higher,
approaching 100 dB/1W/1m. Very efficient speaker.
Time Alignment (Wiki)
This may be the reason that the voice coils of the horn
and speaker are in the same vertical plane. Another
reason may be to make the horizontal pattern the same for
the horn and speaker. Both of these would tend to
make the sound better over a larger area than not doing
it.
The web page on time alignment (http://www.troelsgravesen.dk/Time-Alignment.htm)
shows a case where the frequency range is about 1600 to
4000 Hz and so may not be applicable to the VOT speaker
where the crossover frequency is around 900 Hz and where
the physical difference is voice coil locations would
differ by almost two feet.
|
|
|
1707545
Acoustic device, Edward
C Wente, Bell Labs, 1929-04-02, 181/159 - Horn
speaker/microphone |
|
1812389
Acoustic device, Edward
C Wente, Western
Electric, 1931-06-30, 381/346 - direct-radiator
loudspeaker |
|
1992268
Acoustic device, Edward
C Wente, Bell Labs, 1935-02-26, 181/187 -
sectional horn
|
These may not belong on the sound powered telephone
web page, but I've found some patents and his is where I'm
parking them.
655726
Telephone-receiver, William J Murdock, 1900-08-14, 381/393 - long pole or headphone style
786588
Telephone-receiver, William J Murdock, 1905-04-04, 379/428.01 - long pole
801034
Telephone-receiver, William J Murdock, 1905-10-03, 379/440 - long pole
853186
Telephone, William J Murdock, 1907-05-07, 379/428.01 - long pole case molded with woven
core
1091528
Circuit-detector, William J Murdock, 1914-03-31, 324/555 - headset with series battery and test
probes = audible continuity tester (test equipment, not phone)
1513924
Telephone head set, William J Murdock, 1924-11-04 - similar to
1583088 except pinch screw height adjustment
1583088
Telephone head set, William J Murdock, 1926-05-04 - headband
& two earphones, spring clip earphone height adjustment
Brandes Inc
1447969
Telephone head set, Dietrich Frederick,
Brandes Inc, 1923-03-13, 379/430; 296/139 - adjustable headband, see YouTube
1536482
Telephone receiver, Dietrich Frederick, Brandes Inc,
1925-05-05, 381/412 - matches design in
YouTube video. - specifically mentions ability to take apart
without breaking leads, but in video all the leads were
broken.
1543325
Headband for telephone head sets, Dietrich Frederick,
Brandes Inc, 1925-06-23, 2/209.3;
381/376 - to fit head of wearer
1544136
Electrical connection for telephone headsets, Dietrich Frederick, Brandes
Inc, 1925-06-30, 381/379;
174/36; 381/189; 381/377 - not exposed terminals so B+
from tube radio will not cause electrical shock.
1645231
Electromagnetic sound reproducer,
Dietrich Frederick, Brandes Inc, 1927-10-11,
381/160; 381/432 - triangular speaker enclosure
D71138
Loud Speaker, Dietrich
Frederick, Brandes Inc, Sep 28, 1926, D14/211 -
Condenser Microphone
1333744
Telephone-transmitter, Edward
C Wente, WE,
1920-03-16, -
Throat Microphone
I've read that these always sounded garbled and so were not
used for very long.
2121778
Sound translating
apparatus, Ballantine
Stuart, 1938-06-28 -
2121779
Sound translating apparatus, Ballantine
Stuart, 1938-06-28, - cited
by 25 patents
2121780
Sound translating
apparatus, Ballantine
Stuart, 1938-06-28, -
2121781
Sound translating device, Ballantine
Stuart, 1938-06-28, -
This NT-51007A (NSN: 5965-665-3480) is NOT a sound powered
unit, but rather a carbon microphone type.
Patents
Related to the 51007-A handset. The 51007 has a
carbon mike element. A retrofit kit (Navy-Radio: Xmtr-handsets,
NT-51007a)
replaced the mike and speaker with new elements giving the
51007A a dynamic mike with built-in amplifier and circuitry
that allows it to work with equipment that expects to see a
carbon mike element.
Roanwell still
makes the Type 503 H-169/U handset which is
based on an upgrade kit to the 51007 replacing the carbon
mike element with a dynamic element that contains an
amplifier designed to run from the carbon mike DC
bias. This mick element is a noise cancelling design
so your lips need to be touching the mouthpiece. I
think the speaker element was also replaced. Newly
made H-169/U handsets are gray in color.
Navy-Radio: Transmitter
Handsets -
51007A
Carbon Mike element: 35 - 50 [or 35 Ohms +/- 10] Ohms.
1300 Ohms DC! Maybe the mike element is bad?
Speaker Impedance: 600 [or 600 Ohms +/- 150] Ohms. 143 Ohms
DC. 370 Ohms @ 1 kHz
This appears to be a New Old Stock (NOS) handset. The
switch only has a single blue wire.
From
NAVSEA 0967:
page 97:
STOCK NUMBERS FOR COMPONENT PARTS IN HANDSET H-169/U,
FSN N5965-679-9501
Transistorized Type Handset H-169/U, complete with
cord-assembly CX-1846A/U, is now available from stock, under
FSN N5965-679-950l. This handset is used with equipments
AN/URC-32 and AN/WRT-2. In many equipments, it can be used
as a direct substitute for Handset Navy Type 51007A.
Component parts for Handset H-169/U are available from
stock, under the following stock numbers:
Description
|
p/n
|
FSN
|
NSN
|
Handset H-169/U w/cord
assy CX-1846/U
|
RC-10385/C |
5965-679-950l
5965-665-3480 |
5965-00-679-9501 |
| Handset H-169/U w/o cord
assy |
RC-10385 |
N5965-803-438l |
|
| Earphone element |
RC-10379 |
N5965-678-5305 |
|
Microphone unit,
w/retainer ring
|
RC-10367 |
N5965-678-5478 |
|
| Microphone unit, w/o
retainer ring |
RC-29020 |
N5965-624-4l34 |
|
Microphone retainer ring
|
8C-l5014 |
N5965-624-4l4l |
|
| Cord assembly |
CX-l846A/U |
N5965-803-438l |
|
"SHOCK HAZARD ON HANDSETS H-169/U AND N.T. 51007A
It has been reported that a shock hazard exists on a few
Navy handset types H-169/U and N. T. Sl007A. This is caused
by a misalignment of the leaf of spring of the switch which
shorts the push-to-talk button (metal) shaft and, in turn,
places the keying potential on the plate of the switch .
When the switch button is engaged or released , an inductive
kick-back potential is present on the switch plate. If
a handset is considered to be a shock hazard, or if a
continuity check indicates a short between the switch
plate and the plug pins, the handset should be modified as
follows.
1. Re-align the pile-up of the push-to-talk switch in order
to prevent shorting to the metal shaft.
2. Reverse the green and block leads of the switch, which
removes the keying voltagee from the leaf spring which, in
turn, shorts to the metal shaft. Figure l shows the modified
wiring diagram of the handset switch.
3. Determine weather excess solder is causing the short.
The drawing for handset H-169/U has been modified in order
that future procurement of the handsets will be manufactured
to reflect this modification. The handset switch is
available from stock under the Federal Stock Number:
N5930-678-5304."
"H-169/U and H.T.-51007A; Modification of Handsets
It has been reported that the push-to-talk switch on some
H-169/U and NT-51007A handsets bind and in some cases, break
due to the guide pin coming in contact with the metallic
rails directly under the switch .
It should be noted that the difficulty is not
apparant upon visual inspection, but develops while
the handsets are in actual use. If, upon depressing the
button at a slight angle, the switch short circuits to the
two brass rails, the handset should be modified by machining
the rails as indicated in figure l.
Specifications have been modified to prevent future
procurement of handsets with the defects indicated above.
(631)."
page 98:
"H-169/U Handsets - Electromagnetic Interference in
Shipboard Installations
Electromagnetic interference in the H-169/U handset was
detected during a recent survey conducted on the DE-1052
class ships. Investigation has indicated that the H-169/U
handset (containing an unshielded solid state audio
amplifier within the microphone transmitter element) when
physically located in open or semi-open areas, such as
flying bridge, bridge wings or pilot house, are vulnerable
to samples of reflected electromagnetic energy from the
ship's radar. Due to the reflective characteristics of the
ship's structure, sufficient levels of reflected RF energy
are present in the pilot house to degrade radio
communications. The signals are detected and amplified
within the self contained solid state circuit of the H-169/U
and reproduced as a series of audio pulses, representative
of the pulse repetition frequency (PRF) of the offending
radar.
The capability of the handsets (located in the exposed
areas) for detecting the PRF of the radar can be prevented
simply and inexpensively by replacing the existing dynamic'
solid state amplifier transmitter element with a carbon
element as used in the older Navy Type 51007A Handsets. This
carbon element is in the supply system under FSN 9N5965-
586-0831. The dynamic and carbon elements are directly
interchangeable, however, the carbon element will slightly
degrade transmitted audio fidelity.
NAVSHIPS has taken direct action to accomplish this change
to SCN funded ships of the DE-1052 class. Active Fleet ships
(OPN funded) should requisition the carbon elements when
similar electromagnetic interference problems are
encountered. (803)"
Roanwell 51007A
Photos
Fig 1
|
Fig 2
 |
Fig 3 Speaker 10088
 |
Fig 4
 |
Fig 5 Mike element 10118 is from the
NT-51007A (MIL-HDBK-173)
 |
Fig 6
 |
Fig 7 Mike Element 10118: no polarity
marks.
The dynamic mike elements have (+) and (-) polarity
marks next to the electrical terminals.
 |
Fig 8 Carbon Mike Element marked:
Roanwell Corp. 13544 (A)
This has the look of a classic telephone carbon mike
element.
Measures about 1500 Ohms, not 35 Ohms,
so probably needs help or replacement.
|
|
Brush Development Co
|
2383832
Intercommunication system, Alfred L
W Williams, Brush
Development Co, App: 1943-01-29, Pub:
1945-08-28, -
The microphone works by bending a piezo bar. The
call wheel works by bending this same bar. The
microphone also acts as the speaker by means of a
speaking tube that connects the mike and speaker
positions.
Brush Development Co made a lot of piezo crystal based
products.
|
James Wilkes: