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DIAPHRAGM, MORSE RELAY. Used on Morse observation sets to transmit relay armature vibrations to dictating machine. 

A round sounding diaphragm with a mounting projection which is fastened under relay thumb nuts and a fork which engages tip of armature. Dia. about 3".


Used with bridge testing sets. Wood or composition case containing highly sensitive coil and pointer of D'Arsonval galvanometer type. Has shunts to hold down current to coil until circuit is well balanced. L--6 ", W--4 ", Ht--2 3/4".

*Several models have been used, all of which are known by the same name and can be used interchangeably.

HOOD, RESONATOR.   Used as a sounding board for sounders in connection with various resonator supports (See resonator). 

A wooden hood, horizontal base on which sounder sets, and top sloping over sounder making ends equilateral triangle. 

W--6 7/8", Ht--7 1/4", D--5".

JACK, LOOP, WEATHERPROOF, 1-A. Used for terminating loops at ball parks, etc. where standard switchboards could not be used because of exposure to weather. 

Cast aluminum box, with two 200-A jacks set in one end and a condenser 21-AA and 2 Fahnestock clips inside. Wires lead in through a box connector at rear. Condenser normally closes loop but is lifted when plugs are inserted in jack. L-9 1/2m /w--3", Ht--3 ".

JACK, TABLE, .... WIRE.   Superseded by cordless table jacks. Wood base with four to twelve spring clips made to take wedge of old style switchboard.

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Round glass specn. E-50-B. 6" x 8" high. Used on various types of batteries and chemical rectifiers.


Used in ocean cable service for manual transmission. Two keys, on the set side by side on a base 4" x 4 ", Ht--1 ".

KEY, LEGLESS, 2A.*   Used for hand sending on Morse telegraph wires. Oral [sic] brass skeleton base with nickel plated steel sending lever mounted in two trunnion posts. Circuit closing lever is mounted alongside sending lever, both having hard rubber buttons. 

Base 3" x 2" x 1" high. Overall 5" x 2 3/4 x 1 high.

* Leg keys formerly used had threaded brass legs on bottom of base.

KEY, OPEN CIRCUIT. For use on telegraph wires operated on the "open circuit" principle. General construction similar to leg key 2-A, except that circuit closing switch, when closed, engages two separate contact lips, and when open engages a third lip. When the circuit switch is closed, the battery stands "open", and cannot be closed by pressing on the key lever until the switch is thrown. 

L--5 ", W--3 1/4", Ht--1 1/4", Wt--1 lb.


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Used for hand sending on automatic terminal sets and repeater on automatic circuits. 

Essentially a Morse key, but parts are mounted on a moulded base and circuit closing lever is replaced by a separate switch. Type 1-A also had brass base similar to a Morse key, but did not have open contact on switch.

Type Where used  Switch  Base L W Ht
1-B* Multiplex and  Universal Rptr. 3 point 5" x 3 " 6" 3 "    1 3/4"
3-A Overland Recorder ccts 9 point 5" x 4 "  6"   4 " 1 3/4"
4-A+ Overland Recorder ccts   6 point Same as 3-A      

* Type 1-AB will also be furnished. This is a 1-A key with switch converted to be like that of 1-B key.

+ 4-AB is a 3-A converted to be electrically equivalent to a 4-A. 


KEY, STRAP, 3 PT., 3-B.

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Used with switchboard voltmeter to secure static line "kick. Flat spring lever set on a slate base. Upper contact on lever normally touches contact on brass arch mounted over the lever. Depressing lever closes contact below. L--4". W--2". Ht--2".
METER, CONTACT ADJUSTING, 1-A, FOR SEMI-AUTOMATIC KEY.   Used to test the adjustment of the contacts on semi-automatic sending keys ("bugs"). Cast brass hollow base with various resistances set inside, and Weston Model 501 DC millammeter with special zero center scale. Has wedge jack on side for wedge of key and has lamp cord lead for connection to battery. L--9", W--5 ", Ht--5".
METER, FREQUENCY 1-A FOR SEMI-AUTOMATIC KEY. Used to measure the transmitting dot speed of semi-automatic keys ("bugs"). 

A cast brass case in which are mounted two magnets, necessary resistances and condensers, and a dial and pointer on the face. One magnet is connect to a clock which will hold magnet circuit closed for two seconds. Key is set on top of case so magnet armature will vibrate it. Wedge of key is put in wedge jack so as to send dots to stepper magnet which operates pointer over dial. L--11", W--10", Ht--6" (Magnet armature extends 6" above top).

MOISTENER, TAPE, ...., ....

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[Note:  For an interesting accessory, see "Cutter, Tape, Thimble, 2-B"]


Used on tape prionter positions for moistening glue on tape before pasting to message blanks.  The hand moistener is a transparent bakelite tube (for water) with a wick projecting from one end, and a guide through which the tape is so passed that as it leaves the guide it passes over the wick.  The table mostener is a rectangular brass water receitacle with a 3/*" x 1 1/2" wick projecting from the top.







6 1/2"

1 1/2"

1 3/4"



2 7/8"


1 1/2"


Kind Battery
Container 1,2,5 gal
Used on Gravity batteries to stop evaporation
Description Heavy mineral
Specn 788-a

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