Ferrograph 724 Owners Manual

Page 2

CONTENTS

Foreword ,.

General Specification
General Description
OPERATING INSTRUCTIONS

Connections

Power Supply . .

Inputs - Microphone
Tuner (radio)
Pick-up Cartridge
Other Sources t.

Outputs - Loudspeaker
Amplifier..
Tape Recorders
Headphones

Deck Operation .

Tape Loading

Tape Speed

Play

Record H

Automatic and Foil Stop
Fast Wind ,

Replay
Bass and Treble Controls

Output Switch . .
Meter Switch

Record .
Interjection
Stereo Models ..
Radio . . . .
Gramophone
Microphone .. .. ..
Characteristics . .
Placement .
Use of Microphone
Monitoring .. . .

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LIST OF DIAGRAMS AND PLATES

Frontispiece

Ferrograph - Uncased Model ..

Jack plug wiring

Rear Panel-Mono

Rear Panel-Stereo

Tape Loading

Turns Counter Graph

Amplifier Controls - Mono
Stereo

Track Dispositions - Half track
Quarter track

Tape Splicing

Auxiliary Socket Connections

Head Block - Stereo

Recorder Chassis - Rear View

Chassis Model Dimensions

Block Diagram - Stereo Models

Recorder Chassis - Front View

Effect of Bass and Treble Controls

Endless Loop Cassette

Deck Mechanics .. ..

Mono Track Dimensions - Model 713

Models 702 and 722

Models 704 and 724

Stereo Track Dimensions - Models 702 and 722
Models 704 and 724

Mono Amplifier Front View
Mono Amplifier Rear View

Stereo Amplifier Front View
Stereo Amplifier Rear View
Mono Power Unit

Stereo Power Unit

Page

11
14
16
17
19
21
22
23
28
29
30
34
37
38
39
41
42
4B
51
55
56
56
56
57
57
58
60
61
63
65
66

Page 11

FERRDGRAFH SERIES SEVEN

OPERATING INSTRUCTIONS

The carrying handle is at the rear of the recorder adjacent to the flap
covering the connection panel. This flap can be raised using the slot.
when the handle can be withdrawn from its recess. The cabinet lid is
removed by sliding the two knobs (one at each end of the recess)
away from the lid. which can then be slid backwards and lifted clear.
It is replaced and secured in the reverse manner.

When 8%" reels are fitted to the recorder. they overhang the deck
slightly and must be removed when refitting the lid. Smaller reels of 7"
diameter or less can be left on the deck, but it is inadvisable to operate
the instrument with the lid in position. as this inhibits the ventilation
arrangements. For the same reason, the square aperture on the underside
of theflcabinet should not be obstructed. as this would stop adequate
air in- ow.

When the Ferrograph is to be operated vertically, the two studs at
the front of the recorder case should be replaced by the two larger feet
supplied with the recorder. The two "press-in"studs should be levered
out of their positions and the new feet screwed into the same two
places so that when the recorder is stood upright, its front face is
inclined backward very slightly. Also. the auto stop control at the
extreme right of the deck control panel should be turned so that the
screwdriver slot is in line with 'V' (see page 20).

The recorder is also supplied with a mains lead, a head cleaning brush:
hexagonal "Allen" keys (33A, 4B.A and 68A) and replacement fuses.

Note. All subsequent references to "mains" in this manual mean
the AC. power supply any. the mains fuse. 0n 117V, 60Hz models
(Sui/ix A). no voltage selectors are fitted.

CONNECTIONS

Except for the microphone input on the front panel, all connections
are at the rear of the recorder r10. Line input, 6000 output, Low Level
output and Loudspeaker output. The mains input is at the centre of
the panel with the mains and QC. fuses either side. These are all 1A
rating. size 20 mm. long x 5 mm. dia. except for the Mains Fuse on the
117V model (Suffix A) which is 20 mm. x 5 mm. dia. rated at 15 Amp.

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The maximum volume (with the variable resistance at maximum) is
still governed by the Output control on the recorder, but adjusting the
remote control will vary the signal from this down to zero.

Signal Operation

The Auxiliary Socket on the rear panel is arranged to accept a Signal
operated Switching Unit, This unit is designed to drive the tape only
when a signal is present for recording and to switch off the tape drive
when the signal ceases. To allow for short gaps in the signal e.g, pauses
in speech. the Switching Unit has a built-in delay of 5-25 secs. before
switching off. Thus by omitting the long silent periods when no signal
occurs. messages, etc., spread over a long time can be recorded onto
a single tape.

After plugging the Switching Unit into the Auxiliary Socket, the
recorder should be set in the "Pause" position with the "Record" button
pressed and the record gain controls adjusted to ore-determined
settings. The appropriate Output Switch must be set to "Source".

SPECIAL APPLICATIONS

Echo Effect

Due to the physical spacing of the record and replay heads there is a
finite delay between the record and replay signals which corresponds
to the time taken for the tape to travel between the two heads. At
7&- in/sec. this is approximately % sec. (.45 sec. at 15 in/sec.. § sec. at
3% in/sec., g sec. at 1% iii/sec). Thus part of the replay signal fed back
into the record amplifier will give the effect of an echo whose magnitude
will depend upon the amount of signal fed back.

The Meter switch should be set to "Source" and the Output switch
to "Tape". A lead should then be connected between the 600 ohm
output and the Line input (Line gain control at zero). The signal to be
recorded should be fed into the Microphone input, and its gain control
advanced to a suitable record level. On turning to Run and pressing
the Record button, the echo can be added to the record signal by
gradually turning up the Line gain control. Care should be taken not
to set the echo too high as this may cause it to build up. leading to
instability.

When applying echo to a stereophonic recording, each channel
should be connected as described above, taking care to adjust the
controlsto give approximately the same amount of echoto each channel,
unless an unbalance is intentionally required.

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