Zenith Royal 1000 Service Manual

SERVICE
MANUAL
MODEL
"ROYAL
1000"
ALL
TRANSISTOR
TRANSOCEANIC
PORTABLE
RECEIVER
CHASSIS 9C14022
“о
the
Sewiceman
GENERAL
The
transistor
portable
chassis
is
a
conventional
super-
heterodyne
receiver
using
an
individual
mixer
and
oscillator
to produce
the 455 Kc intermediate
frequency.
The intermedi-
ate
frequency
amplifiers
are
conventional,
It
is
necessary
to
use neutralization
in the I.F. amplifier
stages
as in circuits
using a triode tube, The 103-22
diode is used as a detector
and AVC voltage
source.
This diode is part of I.F. Trans-
former
T4. This is then followed
by a first audio amplifier
and a driver
stage for the class
B push pull output.
The
121-47
output
transistors
are
a
matched
pair
and
will
be
coded
with paint dots, red, white,
yellow
and green.
Should
one transistor
fail it must be replaced
with another
121-47
transistor
with corresponding
color.
Do not use 121-47
tran-
sistors
in pairs
unless
their color codes
are identical.
. The iron core slugs of the RF, mixer and oscillator coils
have hex-holes through their centers. This will enable the
technician to tune the top slug then drop alignment wrench
No. 68-32 down through the slug to adjust the slug in the
lower coil.
Power Supply — Eight Zenith Z2NL 14 volt or Standard
Flashlight Batteries total 12 volts D.C. Approximate battery
life 300 hours. One Zenith Z2NL 1И volt or Standard Flash-
light
Battery
for
the
dial
light.
- Frequency Ranges:
540 to 1600 Kc 11.4 to 12.3 Mc
2 toá Mc 14.6 to 15.8 Mc
4 to9 Mc 17.1 to 18.5 Mc
9.4 to 10.1 Mc 20.7 to 22.5 Mc
Intermediate Frequency: 455 Kc
,Power
Output
Undistorted:
500
Milliwatts
Speaker:
4
inch
P.M.
Alnico
V,
Voice
Coil
Impedance
—
3.2
ohms
@
1000
cycles
Accessory
Earphone
39-22
Impedance
15 ohms
9 1000
cycles
RESISTANCE MEASUREMENTS
When
making
resistance
measurements
in
the
circuit,
it
is
most
important
to
remove
the
transistors
in
the
circuit
under
test
otherwise
readings
obtained
willbe
incorrect.
This
is
the
direct
result
of a transistor
acting
as a diode.
When
making
measurements
across
an
electrolytic
capacitor,
be
certain
the
ohm
meter
leads
are
correctly
polarized;
also
be
certain
the
battery
voltage
of
the
meter
does
not
exceed
the working voltage of the capacitor, Otherwise damage to
the capacitor may result, :
:
VOLTAGE READINGS
It
is
suggested
that
a
VTVM
with
an
excellent
low
range
scale be used to measure all circuit voltages. All voltages
indicated on the accompanying diagrams have been measured
under no signal conditions and a carbon battery supply
voltage of 12,0 volts. Under these no signal conditions,
a check can be made of the batteries, With carbon batteries,
the total voltage should be 12.0 volts.
COMPONENT
REPLACEMENT
When soldering components at the base of the transistor soc-
ket, it is suggested that the transistor be removed to avoid
any possibility of excessive heat being transferred through
the socket to the transistor. When soldering the low voltage
electrolytics and germanium diodes, it is suggested that the
wire be held with a pair of long nose pliers while soldering.
The long nose pliers will act as a heat sink.
TRANSISTORS
At
the
present
time
we
do
not
know
of
any
satisfactory
com-
mercially available transistor tester.

Zenith Royal 1000 Specifications

General

Type	Transistor Radio
Model	Royal 1000
Manufacturer	Zenith
Tuning	Analog
Material	Plastic and Metal
Wave bands	AM, FM
Bands	AM, FM
Power Source	Battery

Summary

General Receiver Information

Receiver Overview

Describes the transistor portable chassis as a conventional super-heterodyne receiver with specific IF stages.

Frequency Ranges and Power Supply

Details the receiver's frequency ranges and the power supply requirements using Zenith Z2NL batteries.

Coil Tuning Procedure

Explains how to tune RF, mixer, and oscillator coils using hex-holes and alignment wrenches.

Service Procedures and Notes

Resistance Measurement Guidelines

Stresses the importance of removing transistors before resistance measurements to avoid incorrect readings.

Voltage Reading Recommendations

Suggests using a VTVM with a good low range scale for accurate circuit voltage measurements.

Component Replacement Advice

Advises removing transistors when soldering at the socket base to prevent heat damage.

Transistor Testing Information

Notes the current lack of satisfactory commercially available transistor testers.

Repair and Alignment

Recommended Repair Equipment

Lists essential equipment for transistor radio repair, including signal generators, VTVM, and tools.

Signal Tracing Methodology

Warns against 'screwdriver testing' and recommends point-to-point signal checking for diagnostics.

Alignment Procedures

Provides detailed steps for aligning IF, BC, and SW stages using specific signal inputs and trimmers.

Mechanical and Layout Details

Dial Cord Drive Mechanism

Diagram and description of the dial cord drive mechanism, including cord routing and turns.

Transistor and Trimmer Layout

Diagram showing the physical location of transistors, trimmers, and other components on the chassis.

Schematic Diagram and Notes

Main Circuit Schematic

Presents the overall circuit schematic illustrating all major components and their interconnections.

Technical Notes for Servicing

Provides essential notes on component tolerances, voltage measurement conditions, and capacitor replacement.