|
|
|
|
|
|
|
UK Phone Voice Scrambler sa 5030 → ← Overview
|
|
Telephone No. 162
No. 232
|
|
|
|
Telephone set used with scrambler phone
- this page is a stub
|
|
The first scrambler sets that were released in early 1940, used a
green bakelite Tele.No.162 as the voice terminal for scrambled
conversations. The call would be initiated first with a standard black
telephone set of the No. 328 range,
that was also connected to the Frequency Changer [1].
|
Once the call had been setup, both parties would press a button to
go secure (i.e. select scrambled speech) and the conversation
was continued on the green 162 telephone set. Once the call was
finished, both parties would place their handset in the cradle to
terminate the connection.
The Tele. No. 162 was actually the GPO version of the Neophone, made by
Siemens Brothers 1 of Woolwich. It was introduced by the GPO in 1929
and is nicknamed The Pyramid. 2 The sets were
available in black (bakelite), and later also in Jade Green,
Chinese Red, Ivory and mottled Brown 3 .
|
|
|
|
The 162 had a No. 164 handset, which in this case was also green.
Shortly after its introduction the 162 became a popular model and
was re-released in the Tele. No. 232. The version without the dial
was known as 232CB. None of the 162/232 models has a built-in bell.
If a bell was required, an external bell unit could be fitted elsewhere,
or (optionally) at the bottom of the unit.
|
-
Not to be confused with the German manufacturer
Siemens & Halske.
-
This nickname was introduced in recent years by collectors and was
not used at the time.
-
Although the coloured versions are commonly said to be made of
Bakelite, they were actually made of Urea Formaldehyde, which was
– like Bakelite – one of the first plastics.
|
The image on the right shows the device that was a supplied with
the Frequency Changer 6AC/3 in our collection. It has a
bakelite body, no dial, and as the drawer fitted at the bottom.
It is fitted with a bakelite No. 164 handset. 1
The cradle is made of bad (deteriorated) plastic. 2
As the unit is only used for its handset — the microphone and speaker
elements are connected directly to the voice circuits of the
Frequency Changer — it is not fitted with an induction coil
(transformer). The hook switch in only used to interrupt the connection
to the microphone.
|
|
|
It can not be used to make calls, nor can it be used to accept
calls. According to the instructions on the circular Secraphone label,
the call had to be initiated on a regular telephone set (that was
connected in parallel with the Frequency Changer.
Once the call was established, the user could pick up the unit's
handset, after which the handset of the regular phone was replaced.
As the unit has no markings or stamps at its bottom whatsoever,
we have given it the provisional name TMC-232X, indicating that
it was made by TMC and that it was used for a special application.
➤ More about Frequency Changer 6AC/3
|
-
Instead of the normal No. 164 marking, it has the letters 'TMC'.
-
The cradle is made of a poor quality plastic, and had become brittle.
|
Below is the circuit diagram of the simplified TMC-232X telephone set.
It has been modified for direct operation with the Frequency Changer 6AC,
and is used for its handset only. Note that the two contact pairs of the
hook switch are used for disconnecting the microphone and also for disconnecting
the DC voltage that is needed for the carbon microphone, when it is on-hook.
Note that a different connection pattern is required when using the telephone
with the Frequency Changer 6AC/3, as the latter has a slightly different
internal wiring of its terminator block.
|
|
|
|
Any links shown in red are currently unavailable.
If you like the information on this website, why not make a donation?
© Crypto Museum. Created: Wednesday 26 May 2021. Last changed: Sunday, 06 June 2021 - 08:21 CET.
|
 |
|
|
|
