Contemporary Commo Equipment












TA43/PT, Western Electric predecessor to the TP312
[picture donated by Mike Brueckmann]
TA43/PT
 
 


TA-312


The TA-312/PT is a two-wire, battery-operated field telephone. It may be used in a point-to-point wire system or in any
two-wire ring-down subscriber position of a telephone communications system. The Handset H-60 contains a push-to-talk switch which connects power for talking. The TA-312/PT has a built-in Receptacle Connector U-79/U for use with a headset and an associated EXT-INT switch.  These proved to be some of the best and most rugged pieces of telephone equipment used by the U.S. Army.  Evidence of their superior but simple engineering-as the older models where replaced for use by the Regular Army, they were handed down to the National Guard in serviceable condition.
Some of them where still in use thirty years after their manufacture.
 
 

ta-312 with canvas bag
 
 
 
 
 

A picture donation from Rolf Taylor:
Here are the picture of the 312 with the adjunct dial pad. It uses its
own type J battery.

It has a flap that extends to cover the magneto crank, to prevent use of
the magneto when tone signalling is used.

I believe that with this adaptor installed and the selector switch set
to CB the unit should be usable on any normal POTS line.

The adjunct pad is labelled:

(first Label)

ADAPTOR, TONE SIGNALLING TA-955/PT
STAR DYNAMIC CORP P/N 2140

(second & THIRD labelS, on magneto cover flap, inside and outside)

WARNING DO NOT REMOVE COVER EXCEPT FOR RADIO LOOP TO THE SB-3614

(fourth label, ON BOTTON)

<--- Connector

<-REMOVE SCREWS TO CHANGE BATTERY->

ADAPTER, TONE SIGNALLING TA-955/PT
STAR DYNAMIC CORP. P/N 2140
5711 KENNEDY BLVD.
NORTH BERGEN BLVD, NJ 07047
SERIAL NUMBER 2614
CONTRACT NO. DLA900-87-C-0993

<-REMOVE SCREWS TO CHANGE BATTERY->
 
 










 
 
 
 
 
 





top view TA-312 in bag
 

ta-312


 TP-6-A
TP-6-A
   The TP6A was built around the WE302 design--you can find Connecticut, North and WE versions---and many of the C & N versions had WE parts such as dials and transmitter/receiver elements.    The AE black box magneto set you have was not built for the military but for railroads, etc, Mine is marked Union Pacific.  They were not built heavy enough for the rigors of combat and 19 year old grunts.
Mike

Ok, Someone want to send me a pic of a "real"  TP-6-A?

I suspect that as the Auto. Elect. dial was the only commercial dial approved by the Signal Corps (so that the Telephonics and Nanasi are
copies) that in the beginning of TP-6 designation all the examples were originally outfitted with Auto. Elect. dials and only later were those
two companies contracted to supplement the demand for such a dial design.  One can speculate that for some reason the W.E. dial (which
could have been produced in sufficient quantities) was judged unsatisfactory.
Marshall
and note that up to December 1954 (The latest version of the TM that I have seen) W.E. dials will NOT correctly be found in TP-6-A units as they were never approved "by the S.C. on substation equipment except the dial used with the TA-236/FT." (the W.E. 500 set version).
Telephone collecting Precision is not easy!
Marshall
Please amend my original comments about the manufacturers of TA-45(*)/GT dials.  I do not have an example of a TA-45B/GT dial and do not know if the design is A.E. or other (I will ask the listserv for A.E. info); all I know is that the A.E., Telephonics, and Nanasi dials all have shunt cams and pulse cams whereas the TA-45B/GT has a shunt cam and an impulse WHEEL.  Also the TA-45(*)/GT dials all require a dial adapter for use with the North sets.
In addition, as many of the TP-6 sets were furnished as MANUAL versions, subsequent insertion of non Signal Corps approved dials would not convert them into proper TP-6 units.
Marshall

TP-6 represents eight different commercial model desk-type telephone
sets, viz.:
1) Western Electric Co. No. 302A W-3
2) Auotomatic Electric Co. No. 40
3) Kellogg Switchboard & Supply Co. No. 925BAX
4) Stromberg-Carlson Co. 1222BW
5) North Electric Mfg. Co. No. 3H6SL
6) North Electric Mfg. Co. No. H-600SL
7) Stromberg-Carlson Co. No. 1242WA

Also, several of these equipments have individual nomenclature, viz.:
2) TA-101/FTC
3) TA-102/FTC
4) TA-113/FTC.

TA-107/FTC looks externally like the North sets but whose base plate looks like the WE turned 90 degrees.
Also, the TP-6A, by Conn. Tel. & Elect. Corp, eventually was given the TA-241/U designation.
 The dials in the above sets must be TA-45/GT, TA-45B/GT or TA-45C/GT, which were (as far as I know) only manufactured by Auto. Elect., Telephonics, or NANASI CO. INC.  This means that the TP-6 designation was only given to those sets with the TA-45(*)/GT dials; no WE, North, SC dials permitted!  Also note that the TA-45(*)/GT dials by
Auto. Elect are just marked Auto. Elect. with the five and two sets of contact screws with connecting strap.
Much of this info is contained in TM 11-468, "Substation Maintenance"; a manual I'm still trying to find, in case you come across any!
Regards,
Marshall
 


 
 

Go to the USN and USMC telephone equipment page


 

TA-1
TA-1/PT TELEPHONE, sound-powered unit requires 2-conductor field phone wire connected to another TA-1 for communication without batteries. Palm-operated generator provides approx 100 V to buzz- signal another phone; also visual indicator. Has coil cord with push terminals for wire hook-up and plastic carrying case.
 
 
 
 

TA 954/TT
TA-954/TT NON-SECURE DIGITAL VOICE TERMINAL used in Tri-Tac comm-system: 4-wire set xmits and receives diphase-modulated digital voice and loop signaling info at 16K or 32K bits. 125 ohm line impedance 125 ohms; range 4 km using WF-16 field (no stock). Requires 24-56 VDC, Tone pad has characters 0-9, FO-F-I-P-R-O-C; also Volume L-H Ring - Receive & H-250 handset. Plastic case is EMI/EMC static protected. {I got out to soon to get to use one of these!}
 
 
 

TA 838
TA-838/PT MILITARY FIELD TELEPHONE has push-button numeric tone pad and is designed for 2- or 4-wire
communications; replaces old EE-8 and TA-43/312 field phones. Ringing signal audible only in 4-wire hook-up. TA-838
also operates over standard telephone lines. Rugged thermoplastic construction; re-quires four C-cell batteries.















 
 




TM-5805-243-12 (TA-1/PT): Range, using WD-1/TT Field Wire - 4 miles

TM-11-333 (EE-8):

Type of Wire lines...Miles (Point to point/Switchboard System)

W-110-B, nonloaded...11/2
W-110-B, 5,280-88 (loaded)...19/4
W-130-A...4.5/0.9
W-143, nonloaded...25/5
W-143, 3,300-88 (loaded)...100/20

Open wire

080 copper-steel, 40%...120/24
104 copper-steel, 40%...165/33
128 copper-steel, 40%...230/46
080 copper...230/46
104 copper...360/72

TM-11-678 (Fundamentals of Telephony):

Wire...Miles (Single Pair- Wet/Dry)...Miles (Twin pair strung on poles- wet/dry)

W-110-B...11/18...65/65
WD-14/TT...12/20...70/70
WD-1/TT...12/20..70/70

This TM also has descriptions of various Transmission Lines:

Spiral-four cable contains four conductors in 2-pairs. Each conductor
consists of seven strands of copper, and is covered in polyethylene insulation...

Five-pair rubber cable contains ten conductors, arranged in five
pairs...Each conductor is tinned solid-copper wire, covered with rubber
or latex insulation...

Toll cable differs from the two types just described primarily that its
outermost covering is made of lead...The wires sizes customarily used
are # 19 and # 16...

Field-wire Lines...consist of simple pairs of insulated wire twisted
together...They are used primarily for short lines, because of their
high transmission loss. The military designation for the field wires
most commonly used are W-110-B, WD-14/TT and WD-1/TT... Each of the two
conductors has seven strands, of which four are copper and three are
steel. Each seven strand conductor is covered with polyethylene
insulation and an outer protective covering of nylon.

(Keith, if you exhaust all other sources I have some of this somewhere I
looked and could not find it, but I'd be willing to look again)

TB-Sig-223 (Field expedients for wire and radio) discusses loading and
use of twin pairs to extend range.
 

Rolf Taylor


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