BELL (ANTWERP)
TELEPHONES


These telephones were made between 1956 and 1966 in Antwerp, Belgium at The Bell Telephone Works.  They have a Zinc alloy case and a large brass carrying handle (folded down in pictures).  Originally the phones were just a solid colour, black or white, but as the RTT prefers to recycle it's old equipment overseas, many of these phones found there way onto the second hand market and were either stripped back and coppered or re-sprayed and fitted with decals.

The Belgian state telephone company, RTT (Regie der Telegraaf en Telefoon/Regie de Telegraphe et Telephone) requested two suppliers, ATEA and BTMC, to come up with a standard telephone together.  The new design appears to be based on a prewar design by ATEA, which got a US Patent in 1937 and was called the ATEAPHONE 50.  The ATEAPHONE 50 case was made of Zinc Alloy (Zamac) or Bakelite and were supplied in black with a small number in white.

With some adaptations, such as the addition of the carrying handle, the new phone became the RTT 56 or as the suppliers called it the U56.

The RTT 56A was produced by ATEA whilst the RTT 56B was made by BTMC.

It is advisable NOT to fit an electronic transmitter to these phones, because of the circuit design they tend not to work.

How to convert this telephone to work on PST
Many of these phones were wired to different diagrams.  So please choose the correct one for conversion to the UK system:-

Conversion of telephone with diagram SA15859A-1 and AP209794

  1. Remove original cord and fit UK style cord as follows.
  2. White of line cord to A.
  3. Red of line cord to B with link to C2 removed.
  4. Blue of line cord to C1.
  5. Remove link A to S and fit 3.3k resistor.
  6. Remove the blue wire from the1uf capacitor (Oblong metal canister) and insulate.

Conversion of telephone with ATEA diagram C20021

  1. Remove original cord and fit UK style cord as follows.
  2. White of line cord to 5.
  3. Remove link 6 to 5 and insert 3.3k resistor.
  4. Red of line cord to 7.
  5. Remove the two green wires from the capacitor and join both of the wires to the blue of the line cord.
  6. Rectifier to be connected to terminals 1 and 3 (R and MR).

Conversion of telephone with ATEA Diagram C55027

  1. Remove any links found between terminals 5 & 6 and 7 & 8.
  2. Insert a 3.3K resistor between terminals 5 and 6.
  3. White of line cord to terminal 5.
  4. Red of line cord to terminal 7.
  5. Blue of line cord to terminal 4.
  6. Rectifier to be connect to terminals 1 and 3 (R and MR).

Conversion of telephone with TMA diagram ST121

  1. Remove original cord and fit BT style cord as follows.
  2. White of line cord to A.
  3. Remove link A to S and insert 3.3k resistor.
  4. Red of line cord to B.
  5. Remove the two wires from one side of the capacitor and join both of these wires to the blue of the line cord.
  6. Rectifier to be connected to terminals 1 and 3 (R and MR).

Conversion of telephone with RTT diagram ST141

  1. Remove original cord and fit BT style cord as follows.
  2. White of line cord to A.
  3. Remove link A to S and insert 3.3k resistor.
  4. Remove link B to C2.
  5. Red of line cord to B.
  6. Blue of line cord to C1.
  7. Locate the 1uf capacitor.  It has two tags, one has one wire on it and the other has two wires on it.  Remove the single wire and insulate the end of the wire.
  8. Rectifier to be connected to terminals R and MR.

 

 
 
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Last revised: July 18, 2021

FM