E-89-A Telephone Repeater

Brooke Clarke 2013

E-89-A Telephone Repeater


These were used to increase the reach of phone lines.  The neat thing is that it's an amplifier that amplifies the signal between A and B as well as the signal between B and A, that's to say each terminal pair is both an input and an output.  For this to work the lines need to have the same impedance looking each way from the amplifier.  The functional check is to short either the input or output and listen on the earphone to see that the amplifier is oscillating at all attenuation settings.


There are two ways to power this repeater: either use a BA-40 combined 1.5 & 90 Volt battery by means of the 4-prong plug, or use seperate BA-23 (No. 6) 1.5 V battery and two BA-36 45V batteries in series by means of the 4-prong socket to 4-wire cable.

The single tube is the VT221 (3Q5GT).  There's a single Trimm earphone to monitor conversations going in either direction.

To test operation just short either pair of line terminals and there should be oscillation at all settings of the attenuator.

Normal 20 Hz ringing can be employed on lines equipped with these repeaters.  Ringing signals are transmitted through the repeater.
Made when W-110-B was the common filed wire, but will work with WD-1 field wire.


Fig 1 Overall view
Signal Corps U.S. Army
Telephone Repeater
E-89-A Telephone
Fig 2 Instructions & Circuit
E-89-A Telephone
Fig 3 Battery Box & Front Panel
E-89-A Telephone
Fig 4 Front Panel
E-89-A Telephone
Fig 5 Inside top left
E-89-A Telephone
Fig 6 Inside back right
E-89-A Telephone
Fig 7 Inside Bottom
E-89-A Telephone



Short Line A terminals and hear if the unit sings into the earphone at all attenuation switch settings.



TM 11-2006 July 1943 Operation, Moistureproofing & fungiproofing

TM 11-4301 General requirements of repaired equipment (not E-89-A specific)
TM 11-4302 Tactical Switchboards and Long Lines Equipment, Repair Instructions, Apparatus Requirements
TM 11-4407 Aug 1945 - 4th & 5th echelon repair - Repair Instructions, Operational Requirements & Testing (Note:  This is a War Department manual)


Patents in general, not specifically for this unit?
The 21-Type Repeater (Lectures in Physics) - single tube amplifier - The EE-89 is a single tube repeater.
Bell System Technical Journal 1931-07: Vol 10; Issue 3 - (sim_att-technical-journal_1931-07_10_3.pdf) - "Negative Impedances and the Twin 21-Type Repeater"
Ref: The Dynatron, A.W. Hall, Proc IRE Feb 1918 (GR Experimenter Vol IV, No. 12, May, 1930)

Passive Repeaters

542618 Telephone Relay or Repeater, C.H. Arnold, 1895-07-16 -
542619 Telephone Relay or Repeater, C.H. Arnold, 1895-07-16 -
791655 Telephone-current reinforcer or relay, Herbert E Shreeve, AT&T,1905-06-06, -
835037 Telephone repeater circuit and apparatus, Herbert E Shreeve, AT&T, 1906-11-06, -
863230 Telephone repeater circuit, Herbert E Shreeve, AT&T,1907-08-13, -
990365 Telephone repeater-circuit, Carl August Kruckow, McMeen & Miller, 1911-04-25, - the heart is the coil design
1015768 Automatic telephone circuit and repeater, Charles Adams-Randall, Randall Telephone Mfg, 1912-01-30, - uses carbon mike type amplifier
1474038 Telephone repeater circuits, Edgar D Johnson, WE, 1923-11-13, - uses carbon mike type amplifier

Tube Type Repeaters

1495422 Transmission circuits, Robert C Mathes, WE, 1924-05-27, - The 21-Type Repeater
1504135 Telephone repeater circuits, Nyquist Harry, AT&T, 1924-08-05, - Type 22 Repeater.
1566311 Telephone-repeater circuits, Alva B Clark, Ray S Hoyt,
1734113   Telephone repeater circuits, Alva B Clark, Crisson George,
1814775   Telephone repeater circuit arrangement, Urmston James, Smith Frederick Stretton,
2223200   Telephone repeater control circuit, Herbert W Augustadt,

Related Telephone & Test Equipment

Phones -
Bell System 302 Dial Phone -
Bell System 500 Dial Phone -
Bell system 2500 Touch Tone phone -
EE-8 Telephone Set
KY-68 Secure Field Telephone
KX-TA824 Panasonic Phone System up to 8 incoming lines & 24 extensions, supports dial phones
TA-1 Sound Powered Telephone Set
TA-312/PT Telephone Set  (Field Phone)
TA-838/TT Telephone Set
TA-1042  Digital Non-Secure Voice Terminal (DNVT)
TG-5-B Telegraph Set
Western Electric 202 Dial phone-
VOIP - Voice Over Internet Protocol (free domestic phone)

Test Equipment
Harris TS1000 ADSL Test Set
HP 4395A Network Analyzer with the HP 4380S CAT 5 Cable test System
Telephone Tool Kit
KS-8455L2 -  lineman's & installer's test set
MK-356/G Wire Splicing Kit - missing the splices.
ZM-4B/U Resistance Bridge
Telephone Poles
SB-22A  Switchboard
SB4170 Military Telephone Switchboard
GRA-39 Radio Set Remote
Z Impedance
Z0 - transmission line impedance including CAT5 and Open wire telephone lines


US Army Signal Corps: Telephone line transmission equipment - EE-89 "Two wire voice frequency intermediate repeater for use on lines with 20 or 1000-cycle signalling. Provides thru simplex telegraph operation. Uses one battery BA-40 which last for about 2 weeks."
Back to Brooke's Products for Sale, Telephones, U229 Audio Accessories, Audio Connectors, Military Information, Electronics, Home page
page created 2 Oct 2013