Zenith royal 300

Page 1

VOLUME R-18, MOST-OFTEN-NEEDED

1958 RADIO SERVICING INFORMATION

mm Chassis 7AT42 81 7AT42ZI

Model "Royal 300"

CHASSIS IDENTIFICATION

The Roan 300" seven trlnsistot portable Ins been produced
with two basic chlssis. This expedient Ins necessnry to
noble us to produce sufficient quantities by using trunsiston
from seven] sources. Both chassis have the chassis number
gnu-med on them Is veil as a color 1denrifying code on the
buttery compirtment just above the butt ery insullnrion 1nsrtuc-
rion label.

(Continued on page 183)

The 7Al'42 chsssis uses rr-nsistors manufactured by Sylvnnis.
The 7AT4221 ch-ssis use: rrnnsistors mnnuf-crured by Tex-s
Instrument. In uddition to this, both chnssis have individual
unliiiiu 1.7011 l-bels. .he caller e: the p; .5
lubels conforms respectively to the color dot on the chassis.
The uccompunying Chlt't gwes I" the necessnry information on
chlssis number, color dot. rr-nsisror layout lsbels. trsnsisror
numbers, Zenith put number, RETMA pert number (where
uvlillble), tnnsistot supplier, etc.

Transistor
Layout Crystal
Chassis Lube! F1111 Diode
Che-sin (3010de Color No. Mixer 01c. 1.1.1.17. 2ndLF. Detector Driver Supplier
71142 Green Green Zenith 121-22 121-21 121-70 121-71 103-19 121-7 121-11 Symm-
102-3498 11151-114 211194 211193 NPN NPN 1mm; 2N3; zms-zmi
Type NPN NPN NPN Mstched Pur
NPN NPN
711-4221 Red Red Zenith 121-54 121-53 121-50 121-51 103-19 121-52 121-19 Tex-s
102-3474 Type PNP PNP NPN NPN 1NB7G PNP Muched P-ir Instrument
PNP PNP
cw OSCILLATOR TRIMMER 0'0 050- TRM
cm ANTENNA mmmew mom-:11 PAIR cu 1141, Tame-j KWGWD PM
\1 1 m, "MM...
T3 31101! TRANSFORMER\ SR \LEP ré IKE '"" "W
B
Q
12 2ND 1;. TRANSFORMER\ . T2 2" ' F "W5

T6 OSUUJCI'OR TRAISFORMER

TI 151 IF. TRANSFORMER

M i; i
\ll Ill

rs osc. TRANS.\

d

NVD
it!

' ' I "" (Q r 'l 1 "w a w
105 flab! i i 43-] J
39410.11: 111w
TRANSISTOR k TRIMMER LAYOUT TRANSISTOR a TRIMMER LAYOUT
F0?- 7A1'42 FOR 7A1'4zz1
Allgnment Procedure
Input Signal Connect Inner Conductor Comect Outer Shield
Operntlon Frequency From Oscillator To Conduc or From Set Diet A! Trimmers Purpose
Gschi' To
1 455 K'c Chem, 600 KC Adi. Ti, 12. For 1.1:.
T3 for mnxi- Alignment
ONE mum output.
2 1620 KC TURN __ _ Glng ClC Set Oscillator
" s sun-w:
35 KC COUPLED Clogegd 111 T6 to dill sclle.
4 RE PE AT T0 __ _ _ _
STEPS 2 at 3 WAVEMAGNET
5 1260 KC - 1260 KC ClA Align loop Int.

182