COMMON WEALTH ERICSSON WALL TELEPHONE


Many articles have appeared in Australia on the Ericsson wall telephone, known to us as Commonwealth Ericsson model. It first appeared before the turn of the century and was adopted by the newly formed PMG Dept in 1901 as the standard magneto telephone throughout Australia.

The models produced by L M Ericsson were:-

Type Old cat no. Magnets Ringer res. Wt. kg
AB 530 345 4 300 ohms 8.7
AB 535 - 4 1000 ohms 8.7
AB 590 346 5 2000 ohms 9.2

The above models were full size. A 3/4 size phone was produced with 3-bar magneto, for use on short distance services and a miniature model (1/2 size) with 2-bar magneto was available for intercom purposes. However, this discussion is only about the standard model which was elected for use in Australia because of its long distance capabilities.

A panel discussion on this phone took place at the September 1988 ATCS meeting, A lively discussion resulted, with considerable input form the panel, members of the audience and details submitted by members unable to be present. The phone was considered point by point and the following details in abbreviated form were the outcome. Some of the information may not be strictly correct and if anyone can make any corrections it will certainly be appreciated.

TIMBER CREST
Very Early models had a spear pointed crest; this was followed by the fairly plain crest with fleur-de-lis type incisions up to 1903 after which the carved crest (stamped?) was standard.

 

early crowncrown3 crown4


LINE TERMINALS
Lacquered brass initially, superseded by frosted nickel plate later. Terminal thread was generally 2BA but at least one other thread type has appeared.


 term id

LIGHTNING ARRESTER
The standard form was two flat discs secured in place by recessed-top terminals. Circular insulated washers have variously been black ebonite, empire cloth or mica with several holes punched. It was thought mica might be English.

GONGS
Always the large type, brass, nickel plated, with raised section around hole.

BELL POSTS
Located by two screws and arranged to provide adjustment:

RINGER COVER
Early models were one piece stamped metal with rounded edge at top. Later were two pieces with square edge. The diamond shaped squiggle transfer stated to be most common The 'L M ERICSSON, PATENT, STOCKHOLM' transfer appears to be earlier. Maybe the diamond pattern was standard for Commonwealth Ericsson and the other transfer appeared on other imported phones. British made phones had 'ERICSSON, ENGLAND' on the cover. The lightning flash transfer down each side should be applied with the top and bottom points outwards.

RINGER MECHANISM
1000 ohm for AB 530 and 2000 ohm for AB 590. Some phones have letter 'B' between bells to indicate use in bridging circuits.

BUTTON
Early models, plain ebonite button; later models, brass screwed-in fitting with ebonite knob on top. Depressing the button opens the circuit to bell when ringing out (silences bell) and short induction coil secondary (improves strength of signal when listening).

SERIAL NUMBER
Stamped on front edge of shelf. Date of manufacture can be ascertained from this. Significance of other numbers and letters sometimes appearing near serial number were not known.

MADE IN SWEDEN
Generally stamped on left hand side of shelf but no invariably.

PAPER LABEL
Attached inside hinged front gives information on ringing ability of generator plus date of manufacture (probably date of test).

LINE FUSES
Initially standard for Commonwealth Ericsson but deleted in later phones.

SELECTOR LINKS
Standard for commonwealth Ericsson. Selective ringing could be applied on party lines, ringing L1 to L2, L1 to E, L2 to E.

BATTERY TERMINALS
Early models have a long stem but later models had terminals set in wood block.

AUXILIARY RECEIVER HOOK
On front curved portion but not always provided. Some phones without hole and some have wood plug or metal disc to cover hole.

MAGNETO
Usually 4-bar but 5-bar available for long distance lines. Of the sliding shaft type.

HOLE LEFT HAND SIDE
Presume used to form radius on side pieces of battery cover. Side pieces identical except for larger hole on right hand side for magneto handle. Left hand side plugged and fitted with small disc.

BATTERY COVER
Mild steel with wood grain finish. Up to 1903, flat across front with wood strip down centre. After 1903, battery cover centre was formed by pressing the steel, eliminating wood piece.

BATTERY COVER TRANSFER
Initially a circular logo was used featuring skeletal phone in centre. After 1904, transfer changed to incorporate 'L M ERICSSON' above plain skeletal phone and 'STOCKHOLM' below. Phones manufactured in UK had skeletal phone only in the transfer. At some stage a change was made to depict the skeletal phone in gold instead of silver.


CIRCUIT DIAGRAMS
Only supplied in British made phones when it was pasted inside the battery cover.

BATTERY SHELF
Heavy steel plate painted black. Early models simply a flat plate secured by screws along back edge. Later models had substantial return on plate and secured by screws into back of board.

BACKBOARD
Substantial timber (about 1" thick) generally in on solid piece, but sometimes with a vertical joint to join two pieces of timber together. Some phones have appeared with a vertical piece each side, filled in top and bottom with separate pieces of timber.

TYPE OF TIMBER
Mostly walnut but occasionally in oak, the oak models also being made in Sweden. This phone did not appear to have used veneer as so many other models did. TIMBER FINISH: Plated finish was always nickel - never renovate with chrome plate.

TORTOISE SHELL PROTECTOR
Attached to left hand side to protect woodwork against damage by handset. Material was actually celluloid, finished in tortoise shell pattern, which as it ages tends to shrink and crack over the years.

HANDSET
Early models had thick microphone, wide groove wooden hand grip and ebonite ear cap. Changes evolved gradually but by 1903 the handset had thin type microphone, fine groove ebonite grip and ebonite insert on receiver, held in place by knurled metal ring. Cords were green or brown, terminating in 4-pin plug.

COMMONWEALTH CIRCUIT
Made specially for Australia to connect handset receiver and auxiliary receiver in parallel instead of standard Ericsson procedure of connecting them in series. This was simpler and assured continuity of use in the event that a cord or receiver became open circuited.

From the Australian Telephone Collectors Society 11/88


Last revised: November 11, 2006