Motorola "Golden Voice" Radio-Phonograph Repair Journal and
Photos
by Chad Hauris, Retro
Electronics and Audio Lab, Midland, TX. 7/2/06
This Motorola from around 1958 had several problems. First of all, the
record changer was in very poor shape mechanically. This is a VM unit
and we were able to find an exact replacement which worked well from a
Steelman console.
However there was also a power supply problem to the record changer
which was very puzzling.
We found that there was a SPDT switch connected with the AM-FM-Phono
function switch. When the switch was in the AM or FM position, 120 volt
AC was supplied to the amplifier and also to the tuner chassis, which
has a separate power transformer. When the switch was in the "Phono"
position, power was removed from the tuner and fed to the phono. In
this position, the power switch on the turntable also controlled the
amp, to allow it to shut off after the records were done playing.
We devised an clever repair for the problem...which was, that only one
pole of the switch was working, and power was never being fed to the
phono. We installed a 110 volt AC relay into an octal socket in the
space previously occupied by the old filter capacitor which we
replaced. The AM-FM-Phono power switch portion now controlled the relay
coil only. The 110 volt AC was then fed to the common terminal of the
relay contacts, the phono power lead to the "normally closed" terminal
and the tuner power lead to the "normally open".
Therefore with the function switch at "Phono" the relay coil was
off and the power flowed to the phono. With the switch to AM or FM, the
relay coil energized and power was switched to the tuner.
We also replaced all capacitors in the amp and tuner sections. P;ease
click the photos for larger views.
Cabinet front view.
Control panel. There is a tuning eye with a fan-shaped pattern in the
dial.
Replacing capacitors in the amp.
Testing the relay setup on the tuner and amp chassis.
Testing the tuner chassis with new capacitors.
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