|See also Autodial No. 301
C MARKETING INSTALLATION
Issue 2, JAN 1977
Description and Installation
Instruction describes the Autodial No. 302A (Card Callmaker) which enables subscribers
connected to automatic exchanges to call other frequently used subscribers numbers without
the necessity of remembering or dialling the telephone numbers. To call other subscribers
the normal telephone dial may be used.
The autodial is a "repertory dialler" with a punched card memory and is used in
conjunction with the normal telephone. Each telephone number is punched on an individual
card, which has a capacity of 16 digits. About thirty cards can be stored in the recessed
top of the autodial. The autodial is mains-powered with an integral power unit, measures
5.5in x 6in x 4in and weighs 3.5 lb. When the mains supply is switched on, the red opal on
the lid of the autodial glows.
When a punched card is placed in the slot, the autodial pulses the first recorded digit.
The card then drops, under the force of gravity, until arrested by a latch. The next digit
is then transmitted. This procedure continues until all the recorded digits have been
transmitted, when the card drops from the slot and is caught by a transparent tray fitted
to the base.
When a punched card is positioned in the slot, light shines through the punched out holes
in the card on to photocells. The difference in the resistance of the lit and unlit
photocells sets a pulse counter and starts a pulse generator.
The pulse generator sends dial pulses to line and steps the pulse counter until it is
restored to zero, at which time the generator stops and a monostable multivibrator is set
to give an interdigital pause (IDP ) of 850 ms. The latch on which the card is resting is
released and the second latch is operated to allow the card to drop to the position in
which the next row of holes is presented to the photocells.
After this number has been pulsed out, the second latch is released and the first
re-operated, to allow the following row of holes to be presented to the photocells. This
process is repeated until no holes are presented to the photo cells causing both latches
to be released and allowing the card to fall-from the slot. If an exchange line access
digit at a PABX is required to precede the telephone number, the digit is recorded in the
normal manner but one additional hole is punched. When this particular hole is presented
to the appropriate photocell the IDP is extended to allow main exchange dial tone to be
obtained prior to the dialling of the remaining digits. Should an incorrect card be
inserted in the slot, the call may be cancelled at any time during the dialling process by
pressing the button in front of the card slot, and replacing the telephone handset.
The cards (Card, Autodial, D 92879) are supplied in boxes of 50. Each card is 2in x 3in,
has five columns of 16 semi-punched holes and, on the edges, 42 two columns of slots in
which the latch pins locate. A roughened surface is provided at the top, on which to write
the name or other details of the relevant subscriber, and down the left-hand side, on
which to write the number being called. Each row of holes corresponds to one digit of the
telephone number starting from the bottom and working upwards.
This code is derived by deducting the required digit from 16 and punching out the holes
required to total the result. The first column on the left represents the value 1, the
second column the value 2, the third column the value 4, and the fourth column the value
8, e.g. to record the digit 7, 16-7 = 9, 9 is represented by punching out the hole in the
1 column and the hole in the 8 column, the digit 0 must be considered as 10, i.e. 16-10 =
6 represented by holes in the 2 and 4 column. The use of the fifth column of holes is
explained in par 4.
When more than 700 cards are required kit Autodial 3/D 93151, item Code 372724 should be
TO RECORD A NUMBER
A guide is provided to facilitate the recording of telephone numbers on the cards as
(a) Write the name of the subscriber to be called at the top of the card, and the number
to be recorded along the left hand side, starting from the bottom with each digit
coinciding with one row of holes.
(b) Using the guide, line up the first digit to be recorded with the corresponding digit
on the guide and punch through the holes provided.
(c) Slide the card in the guide to locate the second digit to be recorded with the
corresponding digit on the guide and repeat as in (b).
(d) Repeat (c) for third and subsequent digits.
(e) After the last digit has been recorded slide the card from the guide. It is now ready
for use in the autodial.
When a guide has not been provided, the cards should be prepared in the manner described
LONG INTERDIGITAL PAUSE
The autodial automatically inserts an interdigital pause of about 850 ms. The card can be
programmed to provide a long IDP. A special column of semi-punched holes (the fifth) is
provided for this facility. After punching out the digit preceding the long pause, the
hole in the fifth column in the same row is punched out. The hole corresponding to this
facility is designated * on the guide.
The long IDP is 2.5 to 3 seconds on the Autodial No. 302A.
TO MAKE A CALL
(a) Select the bard with the desired name and number on it.
(b) Lift the telephone handset and obtain dial tone.
(c) Insert the card in the slot, with the subscribers name at the top, and allow it to
fall freely into the slot.
The autodial will now automatically transmit the recorded number leaving the call held by
To call a number not recorded on a card the telephone dial is used in the normal manner.
INSTALLATION (see N2312)
(a) Connect a three-pin plug to the mains lead, to suit the socket outlet provided by the
subscriber. If a fused plug is used the fuse rating should not be more than 3 amp. A
three-pin plug must be used and the green/yellow wire must be connected to the earth
(b) Locate the autodial near the telephone. It may be connected in all automatic exchange
areas to any ordinary telephone installation, PBX operator's dialling circuit or any
extension which is provided with a dial. The autodial should be connected to the exchange
line or extension pair whenever practicable by using the existing terminal block.
When the autodial is connected to a 700 type telephone or to a switchboard dialling
circuit the spark quench strap must be removed. This strap consists of a wire link
connected between two pillars and is located on the rear printed circuit board.
On completion of the installation it should be ensured that the subscriber can operate the
autodial, has a copy of the operating instructions and understands that the telephone dial
can be used in the normal manner when a telephone number is required which has not been
recorded on a card, or if the autodial fails to function, e.g. during a mains failure.
(c) Apparatus to be Requisitioned
|Autodial No. 302A
||Item Code 372712
|Kit Autodial 1/D 93151 (Punch and Guide Kit)
||Item Code 372644
|Kit Autodial 2/D 93151 (Box of 50 Cards)
||Item Code 372645
|Kit Autodial 3/D 93151 (Box of 1000 Cards)
||Item Code 372724
The lid is removed by slackening the two screws at the rear of the base and one screw
underneath the card slot projection. Two further screws, passing through the transparent
tray, secure the case to the chassis. The removal of these will allow the chassis to be
withdrawn. Before removing the chassis from the case the mains supply must be
An extract from
C MARKETING INSTALLATION
CONNECTING THE AUTODIAL TO TELEX APPARATUS
There are two versions of the Autodial No. 302A. Mk I or Mk II.
For identification the Autodial has printed on its base the manufacturers code, the
year of manufacture and the suffix ... /I or ... /II to denote the mark number.
Dial Ratio Link on Mk II Autodials
The dial ratio is a preset adjustment by means of a two-position link. To change the dial
ratio remove the lid. The dial ratio link is next to the LKA strap. It will be noticed
that the link is soldered to a post at one end and at the other has a socket which is
pushed onto one of two other posts. Should the socket be on the 66-33 post it should be
carefully removed from that post and pushed onto the 60-40 post.
On no account may any other control on the Mark II Autodial be adjusted.
Adjustment to Autodial
Before adjusting the Autodial it is necessary to determine whether the version to be
adjusted is a Mark I or Mark II version.
Mark I Version
Adjustment can be made by rotating potentiometer RV2 which is located on the left hand
printed circuit board of the Autodial. Access can be gained to the potentiometer be
removing the lid as described in paragraph 4.
Rotation of RV2 clockwise increases the dial ratio.
Rotation of RV2 anticlockwise decreases the dial ratio. Dial pulse speed can be
adjusted by rotation of RV1. On no account may any control on the Mark II Autodial be
If the Autodial fails to function correctly after all tests and adjustments have been made
it must be replaced.
Replace the Dial Test Card in the box for future use by the customer or maintenance
Introduced in 1971.
Extract from an article on Repertory diallers in the POEEJ, Vol 62, page 188,
T. G. SIMMONDS, B.SC., and P. A. BURTON
The Autodial No. 30lA stores its dialling information on plastic cards, each card being programmed for one telephone number by having holes punched out in accordance with a simple code. Any telephone number consisting of up to 16 digits can be recorded in this way.
This autodial is a self-contained unit
with an internal mains-driven power unit, measures approximately 6 in x 4 in x 6 in and weighs 34 lb. In the top of the unit is a card chute through which the card falls during automatic dialling. The card is arrested at each row
of punched out holes by a solenoid latch pin, until on completion of dialling the card drops out into a translucent tray. A storage compartment for thirty cards is provided behind the card chute. A call may be cancelled at any time during the dialling process by pressing the button which is situated in front of the card slot, and replacing the telephone handset.
The cards, which measure 3.5 in x 2.25 in, are moulded in A.B.S. Copolymer with 16 rows of potential holes, each hole covered with a thin web which can be removed as required with a suitable pointed instrument. Writing surfaces are provided along the top and down the left-hand side for the
name and telephone number, respectively, of the called subscriber.
A typical card is shown
to the right, each row of holes corresponds to one digit of the telephone number. The code is derived by deducting the number required from 16, and punching out holes corresponding to the result, where the first column on the left represents the value 1, the second column the value 2, the third column the value 4 and the fourth column the value 8. Therefore, for the digit 7,
code digit 9 must be recorded, i.e. holes punched out in column 1 and column 8. The digit 0 must be considered as 10, hence holes to the value 6 would be punched out. A jig is provided to assist the user in programming cards correctly.
The line circuit of the autodial consists only of the pulsing contact, a mercury-wetted reed with a standard spark quench, and two mask contacts performing a similar function to the dial off-normal contacts. Dry-reed inserts are utilized for the mask-relay functions.
The autodial is normally connected between the incoming exchange-line pair and the telephone instrument, the pulsing contacts being inserted in the B-leg of the line, and one set of the mask contacts being connected across the line. On multiple telephone installations it is necessary to connect the autodial into one of the telephone instruments in series/ parallel with the telephone dial. Both mask contacts are required for this type of connexion, but the autodial spark quench must be disconnected.
A simplified block schematic of the Autodial 30lA circuit is shown below. To make a call the user lifts the telephone handset, obtains dial tone and inserts a selected card in the chute. The card comes to rest against a latch pin, with the bottom row of holes aligned between the light source and the photo-conductive cells which detect the digit value. The presence of the card operates the card-detect circuit, which in turn operates the mask relay, to short-circuit the line in preparation for pulsing, and triggers the
i.d.p. generator. The latter enables the pulsing control circuitry to be used for the control of the first digit in the same manner as for subsequent digits, but without operating the latch control.
The dial-pulse generator is clamped by the output from the i.d.p. generator. The termination of this output triggers a 5 ms timer which provides a setting potential for the
When the 5 ms timer restores, the dial-pulse generator, a free running multivibrator, starts sending impulses to line and stepping the pulse counter. When the counter reaches its home state (binary 0.0.0.0.) it triggers the
i.d.p. generator which clamps the dial-pulse generator, and causes the latch to release for 35 ms. This allows the card to fall and be caught by the latch pin locating in the first feed hole in the card. In this position the second row of holes is aligned between the photo-conductive cells and the light source. This process continues until no punched holes are presented to the photoconductive cells. The number-sent detector then operates, releasing the latch until the card has fallen from the chute, and releasing the mask relay to enable conversation to take place.
If a public-exchange access digit from a p.a.b.x. is required to precede a national or an international telephone number, the access digit is recorded in the normal manner using the first row of holes, but the fifth hole is also punched out. The detection of this fifth hole causes the following
i.d.p. to be increased to two seconds. This allows time for
public exchange dial tone to be connected before the remainder of the telephone number is transmitted.