Grundig 3028 Marlborough Schematic

Page 1

118 RADIO SERVICING

GRUNDIG MARLBOROUGH Model 3028/W/3D

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CIRCUIT DIAGRAM-GRUNDIG MARLBOROUGH MODEL 3028fW/3D

4 General Description: Six-valve (including tuning indicator), four-
waveband (L .W. /M. W. / S W. /V. H. F. ), combined A. M. /F. M. table receiver
with four independent tone controls and three dynamic loudspeakers.
Rotatable ferrite-rod aerial and provision for external aerials. Diode socket
for use With tape recorder.

Power Supplies: A. C. mains, I 10 and 190-2 50 volts.

Valves: (V1) ECC85; (V2) ECHSI; (V3) EM34; (V4) EF89; (V5)
EABCSO; (V6) EL84.

Servicing Notes: R15 provides overload protection for the I. F. trans-
formers and should not be replaced with a resistor rated above% watt. A
check point is provided for the V. H. F. oscillator; this 13 a small piece of wire
behind C5, C19 from which the negatiVe grid bias can be measured With an
Avo model 8 (20, OOO-ohrns/volt) meter (should be approximately 2 5 volts).