Goldring G99 User manual

INSTRUCTION MANUAL FOR
GOLDRING"G.99" TRANSCRIPTION UNIT
Description
This Goldring G99 transcription unit has been developed particularly for those High-
Fidelity enthusiasts who require a unit of high transcription quality, but wish to use a
transcription arm of their own choice. It offers complete freedom in mounting
arrangements.
The G99 is styled in the modem idiom by a famous industrial designer.

The hardened steel centre spindle runs in a sintered bronze bush with a special
thrust pad. The 4 pole constant velocity motor limits changes in turntable speed
to less than 1% for up to 13% change in line voltage. Rumble and hum are
negligible. Maximum wow and flutter is 0.2%. The turntable, which is die-cast
from zinc alloy, is non-magnetic and weighs 8 Ibs. A thick rubber mat is fitted.
Another feature is the push-button on-off switch which also engages and
disengages the drive. A neon pilot light gives the "99" an added refinement. The
switch circuit is entirely click suppressed. A vertical idler wheel transmits
drive from the motor to the underside of the turntable. The speed is infinitely
variable over the range 30/80 r.p.m. and from 15/18 r.p.m., and is altered by
means of a rotary knob which by a system of gears and levers moves the idler wheel
along a conical drive shaft of the motor. A neon-lit stroboscope is built into the
unit and very accurate speed settings are possible.
Specification
AC Mains 200-250V 50 c.p.s.
4 pole constant velocity motor
Continuously variable speed control
8Ib non magnetic turntable
Neon lit stroboscope
Centre spindle is of lapped, hardened steel in sintered bronze main bearing.
Wow and flutter less than 0.2%
Rumble and hum negligible
Turntable speed less than 1% variation for 13% mains voltage change.
Fully positive drive and accurate control through precision conical shaft and
vertical idler wheel. Automatic disengagement of idler wheel.
Dimensions
Front to back 14 ¥ inches
Side to side 13 % inches
Turntable diameter 12 inches
Clearance above motor board dependant on the arm used
Clearance required below motor board 3 inches

Installation and Operation
WARNING The motor is held in position by two transit screws 'B' for safety in
transit. Before the unit is played these must be removed
1. UNPACKING. This unit was carefully checked before leaving the factory.
Observe the conditions of the packing carton for signs of improper handling in
transit. If damage is apparent make an immediate claim to the dealer from whom
you made the purchase. Check that all items shown in paragraph 3 are complete.
2. BASEBOARD. The unit should be mounted on a wooden baseboard ¥2 inch to
% inch thick and large enough to accommodate the unit and a separate pick-up
arm. The board should be cut to provide one large cut-out and drilled for three
holes of 1/8 inch diameter.
The position of the cut-out and the holes may be obtained by either of these two.
methods:
(a) Cover the baseboard with carbon paper laid face downwards and fix the
template in the desired position with drawing pins; then scribe on the heavy
outline of the cut-out, so that the line is reproduced on the baseboard by the
carbon paper.
(b) Attach template to the baseboard with self adhesive tape or with pins, and
prick through the template with a sharp pointed instrument such as a scriber or
bradawl.

Fig 1 Top View
Top plan
A: TURNTABLE SPINDLE
RANSIT SCREWS
C: FIXING HOLES
D: IDLER WHEEL SPRING
E: IDLER WHEEL ARM
F: IDLER WHEEL CIRCLIP
G: SLIDEWAY
H: ON-OFF SWITCH KNOBS
I; MAINS INDICATOR NEON
J: STROBOSCOPE VIEWING APERTURE
K: ROTARY SPEED CHANGE KNOB

Fig 2 Underside View
Underside plan
i:
: SWITCH CLICK SUPPRESSOR
: EARTH TAG
: MAINS LEAD
: IDLER WHEEL
: IDLER WHEEL LOCKNUTS
: MOTOR CONE
: MOTOR POVNOZE

Fig.3. Wiring diegram
3. CONTENTS OF CARTON. The following Items are contained in the carton:
(a) The turntable packed in cardboard sleeve.
(b) Rubber turntable mat.
(c) The motor unit complete.
(d) Fixing screws.
4. MOUNTING PROCEDURE. The unit should be screwed down to the wooden
baseboard by means of the wood screws provided. The fixing holes "C" coincide
with the drilled holes in the baseboard. Having screwed the baseplate into position
remove the two red transit screws "B” which hold the motor "'R" against the
baseplate.

5. TURNTABLE. Place the turntable over the centre spindle "A", ensuring that it is
properly seated. Place loose rubber mat over centre spindle. In order to remove
the turntable apply a sharp tap with a wooden block to the centre spindle while
lifting the turntable.
6. MAINS SUPPLY. The unit is normally supplied for 200/250 volts 50 cycles A/C
mains. Connect the mains lead "N" to your supply, ensuring that before this is
done the unit is in the "OFF" position. An earth tag "M" is fitted to the baseplate
and it is recommended that a separate lead be taken from this lead to either an
earth point on the amplifier or to an external earth point. The unit is now ready
for playing.
7. TO PLAY. Press the button "H" marked "ON". This will switch the motor on and
illuminate the neon light "I". At the same time it will engage the Idler Wheel "O".
Allow a few minutes for the motor to warm up before playing records.
8. SPEED ADJUSTMENT. The turntable speed is altered by turning the speed
change knob "K", To increase speed it should be turned clockwise, and to reduce
speed anti-clockwise. Stroboscopic markings are visible through the window "E".
The Inner band of markings correspond to a speed of 78 r.p.m., whilst the middle
and Outer hands correspond to 45 and 33 1/3 r.p.m. respectively. When the bars
of any one particular band appear to remain stationary, the speed for that setting
is exact. When the bars appear to move to the left the speed is fast, and similarly
when the bars appear to move to the right the speed is slow.
IMPORTANT. Always switch off the motor before switching off the mains supply.

8. MAINTENANCE & SERVICE. The motor bearings and turntable spindle
bearings are self lubricating and no further lubrication is necessary. Should the
slide-way "G" of the speed change mechanism run dry, then a small amount of
Vaseline should be applied. Care must always as taken however that the
underside of the turntable and the idler wheel "O" be kept clean and free from
grease.
IF the turntable does not rotate but the motor is going, then the idler wheel
spring "D" needs replacing.
IF the motor does not operate but the noon light "I" Is on, then the motor has
developed a fault and should be repaired.
IF the neon light does not come on when the unit is switched on, the wiring
should be checked as per Fig. 1
IF the motor continues to turn when the unit is switched off, then the switch click
suppressing condenser "L" is faulty and should be replaced.
IF the speed is erratic or a rumble develops, then the idler wheel "J" should be
cleaned with carbon tetrachloride as should the underside of the turntable and the
motor cone "Q".
Should a flat appear on the idler wheel, then this should be replaced. To replace
idler wheel remove the circlip "F" and unhook spring "D" then lift out the idler
wheel arm "E". The idler wheel is secured by two lockouts "P". Undo these and
slide the old idler wheel off the spindle. Fit the new idler wheel to the spindle,
taking care not to touch the rubber ring. Do not over tighten the locknuts. Replace
assembly and refit spring and circlip.